Global Ground Vehicle & Heavy Machinery Industry Conference 2015

Transcription

1 MSC Software Magazine Volume V Summer 2015 Issue

2 Global Ground Vehicle & Heavy Machinery Industry Conference 2015 Sept 16-17, 2015 Troy, Michigan Register Today!

3 TABLE OF CONTENTS FEATURE STORY 22 EDITOR LETTER 1 Reaching the Apex LETTER FROM THE CEO 3 Simulating the Complete Engineering Process MSC IN THE NEWS 4 Simulation News & Media Coverage PRODUCT NEWS IN-BRIEF MSC New Product Releases CO-SIMULATION SPOTLIGHT 8 Noise Prediction of Moving Mechanisms Co-Simulation Feature 10 Evaluating Suspension Components Earlier in Design Volvo Car 12 System Analysis 15X Faster with Co-Simulation Litens Automotive 14 Tackling Conflicting Performance Requirements Ford Motor Company 16 Simulations Give Insight into Bedsore Problems CEI

4 FEATURE STORY 22 MSC Apex: Latest Release Delivers Dramatic Time-Savings in Mid-Surface Modeling 23 Accelerated Mid- Surface Model Construction Workflow 24 Analyzing Design Modifications Faster TLG Aerospace 25 From Two Days to One Hour Dynetics 26 Aero Supplier Achieves Dramatic Time Savings DEMA 28 The Award-Winning MSC Apex TECH TIPS 18 Marc: Defining Axis of Rotation of a Rigid Body Joe Satkunananthan, MSC Software 19 Patran: Useful Tools for Contact Analysis Christian Aparicio, MSC Software 20 Adams: The New ANCF Object: FE_Part Maziar Rostamian, MSC Software PARTNER SHOWCASE 30 Smart & Collaborative 3D CAE Visualization Solution for MSC Nastran, Marc, and SimManager VCollab SPECIAL SPOTLIGHT 32 Simufact: Welcome to the MSC Family Volker Mensing, Simufact 34 Optimizing MSC Nastran Nonlinear with Multi-Core Technology Intel Simulating Reality Contest Winners 39 MSC Learning Center s e-learning Christopher Anderson, MSC Software CUSTOMER SPOTLIGHT 40 Simulating Complex Package Folding Procedure IIT UNIVERSITY & RESEARCH 42 Adams Curriculum Kit 2nd Edition is Here! Volume V - Summer

5 EDITOR LETTER by LESLIE BODNAR Executive Editor simulating REALITY Reaching the Apex Executive Editor Leslie Bodnar Is modeling and simulation finally reaching higher levels of usability, accuracy, and efficiency? Engineers are telling us, yes. In fact, it is. In this issue, we introduce new technology that is already pushing the envelope by creating dramatic time savings for engineers involved in the initial stages of the analysis process - specifically geometry repair, modeling, and meshing. These mundane and repetitive tasks are where our customers tell us they simply need a new approach, a better one. Our answer MSC Apex. And, this is just the beginning of what s to come. Reaching the top and pursuing greatness in the application of engineering simulation throughout the stages of new product development and into design validation is what we will always strive to help engineers do. Already in its fourth release, MSC Apex is producing real time savings for companies like TLG Aerospace, DEMA, and Dynetics Technical Services. On page 24, TLG Aerospace engineers describe how they were able to reduce geometry cleanup and meshing time by 75%. While DEMA engineers were able to reduce the time required to analyze their design by 60%. See page 26. Also included in this issue is a dedicated Co-Simulation Spotlight. Beginning on page 8, we introduce five stories each describing different methods for applying co-simulation such that engineers are now able to test more scenarios with higher fidelity and better accuracy than ever before through virtual testing. Integration of simulation technologies also cuts development time and drives rapid innovation in products. For example, Volvo Car is coupling multibody dynamics and nonlinear FEA to design lighter suspension systems and look at more design alternatives. See their story on page 10. Litens Automotive is able to achieve a 90% reduction in computation time using the same approach. See page 12. The automotive and machinery industries aren t the only ones benefiting from advancements in co-simulation technology. On page 16, see how it s revealing hidden insights into bedsore problems for hospital equipment manufacturers. Reaching the top and pursuing greatness in the application of engineering simulation throughout the stages of new product development and into design validation is what we will always strive to help engineers do. Thank you to everyone who shared their story with us. Sincerely, Editor/Graphic Designer Marina Carpenter marina.carpenter@mscsoftware.com Assistant Editors/ Graphics Contributors Daryen Thompson daryen.thompson@mscsoftware.com Jennifer Betonio jennifer.betonio@mscsoftware.com MSC Software Corporation 4675 MacArthur Court, Suite 900 Newport Beach, CA Volume V - Summer

6 2015 USER CONFERENCES Simulating Reality, Delivering Certainty Beijing, China May 27 Xian, China May 29 Tokyo, Japan June 4 Paris, France June Brno, Czech Republic June Istanbul, Turkey June Gothenburg, Sweden June 15 Munich, Germany June Napoli, Italy July 10 Queretaro, Mexico August 18 Michigan, USA September Tampere, Finland September 22 Moscow, Russia October 7-8 Budapest, Hungary October 8 Bologna, Italy October 14 Rotterdam, Netherlands October 15 Belgium October 15 Torino, Italy November 11 Madrid, Spain October Pretoria, South Africa March 17, 2016 Pune, India September 4 For more information, visit:

7 LETTER FROM THE CEO by DOMINIC GALLELLO President & CEO MSC Software Simulating the Complete Engineering Process A few years ago I attended a global leadership conference where the attendees on the opening night sat right in the middle of the Los Angeles Symphony Orchestra. They powerfully demonstrated the sounds that an orchestra would make if they were not working well together. It was not good. Finally the conductor took control of all the sections and to no surprise, the music was fantastic. If you think about the number of simulations that take place in a product development process, it is really not much different. If one of the members of the simulation orchestra delivers great results, but they are alone and disconnected from the rest of the development process, it is pretty clear that the results will not be optimal. Over the past few years, we have been assembling the major sections of the simulation orchestra to simulate the complete engineering process: Materials The design of new materials which reduce weight and provide same or better structural integrity with reduced part count, materials that have better acoustics properties, etc. is becoming more and more critical. This can be for materials of chopped fiber and continuous fiber composites as well as metal which is still the predominant material for cars, trains and planes. Design, testing and management of new materials should be a natural part of the design process, not relegated to just a special few. We enable engineers to use the design variables of new, advanced materials with certainty as a natural part of their design process. Fabrication As the materials are chosen, they need to be formed into parts. Forming, forging and other fabrication processes are done by a huge number of companies. Forming simulation we have done before, but annealing, rolling, curing, 3D printing and general simulation of fabrication is something new and offers our customers the ability to use simulation to explore the impact of fabrication on the materials behaviors and the robustness of their designs in the face of realizable material variability. Support the simulation of the as-manufactured spatial property variation to enable parts/systems designers to design to robust manufactured parts with minimal margins. Enable the fabrication engineering departments to decide on the best ways to work the material to obtain the design targeted properties. Parts The ability to quickly model and shape parts for simulation that runs the first time has been difficult to achieve over the years. And now, as light-weighting is driving engineers to refine their parts designs and 3D printing and other fabrication methods are opening new design options, it is even more critical to enable engineers to design the parts. It is no longer enough to validate that the part meets its operational criteria. Make simulation tools easier to use and tie them more closely to the geometrical design parameters. Enable the easy exploration of fabrication methods in the simulation of parts behaviors. Assembly Idealized parts from the traditional design process don t always behave the way you want after being fabricated and then joined to an assembly. Welding, riveting, annealing and spatial variations from strain hardening and forming of steel and aluminum change the characteristics of the subsystems and systems and this cannot be ignored. The joining process is another very important input into the design process to understand overall system behavior and how to exploit it in the design of parts and in the design of the assembly process itself. Systems Getting the system model just right gets more and more challenging. Lightweighting, acoustical optimization, energy management, stability augmentation of the dynamic behavior and more and more specialized load cases coupled with a need to minimize the use of margins of safety to create certainty in the design creates a seemingly endless back and forth between the system model and the myriad of part models. The reduction of just one loads cycle has incredibly positive time and cost impact on the overall development process. Enable the systems model and its criteria to be visible throughout the design process. Simplify the exchange of systems and parts behaviors and properties through the supply chain. All five pieces of the process are now in place. With the building blocks laid down, it offers us incredible opportunities to assist our customers to accelerate not only each piece of the process but also to exploit even greater design improvements by simulating the materials to systems processes. We look forward to working with you to realize the full potential. Volume V - Summer

8 MSC IN THE NEWS Simulation News & Media Coverage Acoustic Simulation Software Helps Appliance Engineers Meet Demands Appliance Design More people are living side-by-side with their appliances in smaller spaces, so they want quieter machines, but not completely silent machines. They want enough sound to confirm the refrigerator is working or the washing machine has completed its cycle, but no more. At the same time that engineers are trying to strike that balance, government agencies are mandating greater energy efficiency and end of life design that minimizes waste and maximizes re-use. Throw cost, style, and size into the mix, and engineers face a tangle of conflicting priorities. Acoustic simulation can resolve that conflict by giving engineers insight for developing products with appropriate sound profiles while balancing other design considerations. Integrating acoustic simulation technology into their design processes provides manufacturers with the insight necessary to know where the balance between consumer preference and government restrictions lies. They don t need the resources of a multinational corporation to do it. They just need to know that they have options for understanding their products acoustic behaviors without raising their costs. Ford Applies New Simulation Technology to Solve Challenges Design World Lugging is a familiar and unwelcome challenge that symbolizes the tension between fuel economy and noise, vibration and harshness (NVH) in motor vehicle design today. Lugging occurs when a vehicle is operating at a high gear and a low engine speed below 2,000 RPM and the driver hits the accelerator. Engineers can adjust the vehicle s transmission to accelerate smoothly in high gear a process called slipping but doing so reduces the car s fuel economy. Therein lies the conflict. Consumers want the smoother rides that slipping the transmission yields, but automotive engineers are under enormous pressure to improve fuel efficiency to meet ever-stricter government mileage requirements. Ford s solution came through a combination of simulation and modeling technology and an open standard for co-simulation called Functional Mock-Up Interface (FMI). Ford created detailed 3D models of the drivetrain and the entire vehicle in MSC Software s Adams multi-body dynamics software. Simulation results demonstrated that a slip of 40rpm slip was the optimal trade-off between NVH and fuel economy. Simulation will help engineers develop vehicles that deliver the comfort and performance required to appeal to customers and the efficiency to meet increasingly stringent fuel economy standards. Nonlinear Forming & Welding Simulation Brings As Manufactured Data to MSC Engineering.com In February 2015, MSC Software acquired Simufact, creators of metal forming and joining simulation software. The software is a popular nonlinear CAE Tool used by the automotive, OEM, aerospace and machine part industries. The tool is designed to reduce the trial and error associated with manufacturing a product on the shop floor. In fact, some Simufact customers have reported that they have been able to cut their physical testing in half, and reduce the cycle time of a new part to a single week when using the software. For MSC users, however, Simufact will help to complete the simulation process chain. This will give engineers the ability to simplify the assessments of their as manufactured designs. 4 MSC Software

9 Simplifying Simulation Scientific Computing World Software that is easier to use allows engineers more time to focus on simulation and analysis of the data rather than trying to adapt to new software, learn proprietary coding languages, or the worrying about how to map algorithms to the latest GPU or accelerator technology. For instance, aircraft noise has become a major concern and in some cases is an obstacle to growth in air transport as numbers of airports place restrictions on the amount of noise that can be generated by an aircraft. Designers and engineers must work hard to reduce the noise of jet engines by placing acoustic liners in the nacelle, a housing that holds engines, or equipment on an aircraft, to minimize the fan noise radiated from the engine. One example of the use of MSC software for acoustic simulation looked at the use of nacelle liners on Airbus aircraft. The company evaluated several different shapes and materials to understand the best performance. Airbus found that it could dramatically reduce the time required to design and evaluate acoustic liners by moving to a simulation-based process using Actran acoustic simulation software developed by Free Field Technologies (FFT), a subsidiary of MSC. Materials to Reduce Vehicle Weight Today s Motor Vehicles A new generation of materials management technology will open a window on lighter, more efficient vehicles. Composites, reinforced plastics, and lightweight steel and aluminum, are being deployed across the automotive industry at record rates to improve fuel efficiency. Automotive OEMs are integrating new materials into parts and assemblies in existing designs and developing completely reimagined platforms around them, such as the BMW i3 and i8. New material systems provide significant benefits in specific weight and stiffness. However, because of their variability due to new manufacturing methods and engineers lack of familiarity with them, new material systems demand significantly more and different types of testing potentially increasing up-front cost. This expansion of testing obligates OEMs to rethink how material systems are managed, and how they must evolve to support wider uses of new materials. Such a system must put materials in the forefront of engineering to use materials as an essential design variable to innovate. The ability to model material properties quickly, easily, and in detail is essential to adopting new materials that will make automobiles lighter, more fuel efficient and, ultimately better for the environment. Class Gives United States Marine Corps Engineers New Analytical Tool Defense Video & Imagery Distribution System In February 2015, the United States Marine Corps put some of its engineers through an intensive nineday training course on Adams. In less than two weeks, the students realized that learning Adams could put them on equal footing with engineers in the private sector. Adams powerful analysis capabilities are giving the USMC the ability to start bringing engineering work back in-house, allowing them to quickly and accurately analyze any vehicle mishaps that may occur. Volume V - Summer

10 PRODUCT NEWS IN-BRIEF 2015 New Product Releases The 2015 product release lineup delivers new event simulations for vehicle modeling, coupled physics, extended material modeling methods, an all-new release of MSC Apex, and a range of advanced engineering simulation technologies for streamlining the analysis workflow. In addition to the releases mentioned below, please expect later this year to see new 2015 releases of Marc, MSC Nastran & Patran, SimManager, and additional releases of Digimat, Simufact, and Actran. New Release Highlights: Adams 2015 Extends Vehicle Simulation Scope for Automotive Engineers The Adams 2015 release delivers new functionality and major enhancements in many areas, especially for Adams/Car. Automotive engineers will benefit from new out-of-the-box, customized solutions for model setup and vehicle event simulations. The new features also give users the ability to create higher fidelity subsystems in their vehicle models. Highlights of the release include: Higher Fidelity Modeling Adams/Machinery Compatibility in Adams/Car - High fidelity gear and motor modeling in car & driveline Nonlinear FE Part Support for Adams/Car Geometric nonlinearity for vehicle subsystems modeling and simulation Adams-Marc Co-simulation Enhancements Easier and faster Multibody Dynamics-Nonlinear FEA Integration New Vehicle Database Provides availability of key vehicle types out-of-the-box New Vehicle Events Full-vehicle Suspension Parameter Measurement Machine (SPMM) - Tune suspension parameters for desired vehicle behavior without costly iteration with physical prototypes Static Vehicle Characteristics (SVC) Computes and reports key metrics of the vehicle at static equilibrium Tandem Axle Suspension Analysis (TASA) Delivers support for tuning of multi-axle architectures For details, please visit MSC Apex Diamond Python Delivers two products; Modeler and Structures + SmartMidsurface The latest release of MSC Apex enhances the engineer s workflow and daily productivity with many innovative modeling and analysis capabilities. The MSC Apex Diamond Python release introduces: The fourth release of MSC Apex Modeler - A CAE Specific direct modeling and meshing solution that streamlines CAD clean-up, simplification, and meshing workflow. The second release of MSC Apex Structures - An add-on to MSC Apex Modeler which now expands MSC Apex to a fully integrated and generative structural analysis solution. New incremental Mid-surface modeling workflow (SmartMidsurface ) for dramatic time savings Diamond Python delivers a solver integrated solution for interactive and incremental structural analysis. Modeling, validating, solving, and exploring designs has never been this efficient and easy. MSC Apex helps users to dramatically reduce the amount of time that it takes to build and validate models, a task that does not add any value to the design process. This frees users to focus on delivering not just acceptable designs but ones that are optimal - in an environment that is fun to use. For details, please visit 6 MSC Software

11 Digimat 6.0 The material modeling platform for simulating a range of composites This latest Digimat 6.0 release brings a series of new features and improvements for modeling and analyzing composite materials, from Short Fiber Reinforced Plastics (SFRP) to Discontinuous Fiber Composites (DFC) and Continuous Fiber Reinforced Composites (CFRP). The new release also introduces Digimat-VA, a unique software solution dedicated to accurate virtual characterization of CFRPs to dramatically reduce the cost and time associated with material characterization and qualification. Digimat-VA, which stands for Virtual Allowables, offers a dedicated integrated workflow starting with easy and efficient creation of advanced multi-scale material models (including micro-level variability and progressive failure), FEA simulations of common test coupons, and automatic post-processing for computing mean strength and A/B-basis values. Any engineer concerned with characterizing a new composite material, exploring the design space or better understanding widespread mechanical properties will find in Digimat-VA a productive solution to save time and money. For details, please visit MaterialCenter 2015 Delivers material data integration and ease of use to dramatically improve engineering simulation workflows MaterialCenter 2015 is an out-of-the-box Material Process and Data Lifecycle Management solution with direct integration into many of the CAE pre- and post-processing tools commonly used by engineers. The integration provides direct support to retrieve a material model from MaterialCenter without leaving the native CAE pre- and post-processing application. MaterialCenter 2015 also enables users to create and edit material data directly from the browser environment. Along with MaterialCenter s Excel integration, this provides a completely traceable system to ensure users are aware of all the modifications made to the data. MaterialCenter is the single point of entry for all of your materials related activities including physical test data entry and reduction, multi-scale materials modeling, approval workflow and the export of simulation ready data to analysis. For details, please visit Material Databanks Secure, reliable, and fast access to material data The MSC Material Databanks are collections of technical materials information in electronic format. The databanks are developed and maintained through MSC s partnerships with premier sources of materials information. They provide a comprehensive source of material property data for use by engineers for design and analysis. Benefits include: Easy access to high-quality, reliable material data from around the world to improve team efficiency and information workflow. Improved quality and consistency with engineering data derived from a single source. Reduced transcription errors with electronic data transfer. Increased accuracy of predictive analysis, product design, and simulation using certified material data records for CAD, CAE, or PLM software. For details, please visit Volume V - Summer

12 CO-SIMULATION SPOTLIGHT MULTIBODY DYNAMICS - ACOUSTICS SIMULATION Noise Prediction of Moving Mechanisms By: Dr. Diego Copiello, Product Marketing Manager, Actran & Yijun Fan, Product Marketing Manager, Adams & Easy5 Introduction The reduction of the development cycle and resources needed for designing quality products is always a major industrial challenge. The integration of different CAE technologies allows making a step forward to this aim. For example, by enabling Multibody Dynamics (MBD) engineers to access preliminary acoustic data in their familiar MBD environment, it allows them to detect unsatisfactory designs even without being acoustic specialist or with the direct support of an acoustic engineer. Moreover, trying to connect the two worlds can lead to loss of information and requires additional manual work for the engineers. On the contrary, with an integrated solution, the data exchange between MBD and acoustic departments would be limited only to some advanced acoustic results. This article will discuss how Adams and Actran, the MBD and Acoustic solutions of MSC Software, are combined and integrated together enabling MBD engineers with the possibility of an insight into the acoustic behavior of moving mechanism early on in the design process. Moreover, the acoustic engineers can still get more valuable information from the further post-processing of acoustic results. Multibody Dynamics Coupled with Acoustic analysis It is generally difficult to predict the noises coming from a moving system like transmission system or gearbox. One, there are complicated moving mechanisms inside the system, and different ways in which the parts interact with each other causing varying contact forces and vibrations. Two, understanding how the dynamic performance can influence the acoustic waves radiated from the gearbox casing is also a big challenge. Without the ability to accurately predict how the system dynamics will impact its noise performance, engineers don t have an efficient method to redesign their systems to improve acoustic behavior. Figure 1. Conventional workflow for MBD-Acoustics integration Figure 2. New workflow for highly integrated method The traditional workflow for such analysis involves three interfaces, Multibody dynamics (MBD) tool, finite element analysis (FEA) tool, and acoustic software. First, Engineers would need to perform the dynamic analysis in an MBD tool to get the dynamic loading on the gear casing surface, and since that time-domain results usually can t be read into Acoustic software directly, they would need to convert the complete structure response in the frequency domain, after that, they can finally read the surface vibration into the acoustic software and use it as a boundary condition. This workflow is fairly laborious and could require several CAE engineers to cooperate together every time there s a change in the design. MSC Software has recently developed a new methodology allowing the engineers to perform the modeling within the Adams interface and get initial results and impressions of the acoustic behavior without manually exporting the results into acoustics software to perform noise analysis. Typical acoustic results are computed via Actran, and displayed in Adams interface, including the acoustic pressure evolution in time at selected positions around the model and audible wave files for listening to the sound. Such new workflow greatly reduces the time and cost to conduct acoustic analysis on moving mechanisms like a gearbox, enabling engineers to do more iterations on the new system design in the same period of time comparing to the conventional method. Indeed, the new methodology fully automates this workflow into a single simulation environment by embedding Actran s new time domain acoustic solver into Adams. This allows MBD engineers to perform a first iteration on acoustic results including the evaluation of the sound quality provided by a specific 8 MSC Software

13 Figure 3. Gearbox model with three gear pairs & flexible casing Figure 4. Acoustic analysis setup in MBD environment Figure 5. Acoustic Pressure evolution in time for the surrounding microphones product design. Thereafter, and only if deemed necessary, acoustic engineers can perform a more detailed analysis by investigating acoustic maps in the time domain or by converting only the most relevant results in the frequency domain. The Gearbox Example With the aim of illustrating the MBD & Acoustic integrated solution; let us consider a gear box for example: the motion of the gearwheels causes the vibration of the gearbox which affects then the physical behavior of the gearwheels leading to a strongly coupled problem. The vibrating gearbox also transmits energy to the surrounding fluid and the acoustic waves radiate from it. Contemporarily, the acoustic waves affect the structural vibration as well. However, if on the one hand the Multibody dynamics and structural simulation domains are usually strongly coupled and shall be solved contemporarily, on the other hand the feedback from the acoustic waves to the structure can be neglected when considering an acoustic radiation occurring in air. This assumption allows the engineers to split the analysis of a vibrating structure into two subsequent steps: the MBD analysis is run first and outputs the structural vibration on the structural domain. These vibrations are used as boundary condition for the acoustic analysis which can be efficiently performed by means of Actran s time-domain solver especially for transient phenomena. Let us also assume a gearbox composed by three gear pairs. The input wheel is subject to a rotation ranging between 0 and 3000 RPMs. To evaluate the acoustic response, we can consider a number of microphones distributed around the gearbox. For example, the microphones could be spatially distributed accordingly to the standard ISO In the Adams model, the gearbox casing is considered flexible to capture its surface response. The rest of the gearbox (like gears, shafts, bearings) are rigid parts. Although the gears are not flexible parts, it is still possible to calculate the tip relief and crowning effects which can impact the dynamic loading on the gearbox casing. After the Adams model is set up, a 5-seconds dynamic analysis is conducted with the rotational speed of the input shaft ramping up from 0 to 3000rpms. From the analysis, we got outputs for all the loads and contact forces of each component as well as the displacement, velocity and acceleration of each system s part. Following the MBD simulation, and while still in the Adams environment, an acoustic toolkit is launched to set up the parameters for the acoustic analysis like the acoustic mesh, radius of the infinite elements, speed of the sound, fluid density, output format, acoustic environment (the material) and so on.. What this toolkit does is that it will convert the MBD results into boundary conditions for acoustic model, and perform the acoustic analysis in the background using the new Actran time domain solver. Specifically, the casing acceleration (or equivalently the displacement or the velocity) and the surface mesh of the casing are used to feed the acoustic simulation tool. As the meshing requirements for the structure model are more restrictive than the acoustic ones, the structural and acoustic meshes are incompatible. This also implies that a projection procedure from the structural mesh to the acoustic one is needed. When the acoustic simulation is done in the Adams environment, you can go to the MBD postprocessor and get some of the acoustic results of this gearbox casing like the acoustic pressure evolution in time for the Figure 6. Spectrogram at one of the microphones surrounding the gearbox Figure 7. SPL of orders 25 and 50 VS RPM Advanced in the integration of CAE technologies enable a reduction of development time and resources. surrounding microphones at each microphone location and sound file (.wav). Figure 5 shows an example of the acoustic response in time domain of all the surrounding microphones; this first result allows the identification of instants and areas where the acoustic pressure could exceed unwanted values, which means some potential noise issues. Moreover, these data can be converted in audio files to get the audio quality of a certain gearbox design directly in a single simulation environment, enabling MBD engineers to detect unsatisfying results from an acoustic perspective. Time domain data can be further converted in the frequency domain thanks to Actran s utility ICFD. Thereafter, results can be postprocessed in ActranVI to get a thorough understanding of the acoustics. For example, Figure 6 depicts the waterfall diagram of the noise at a microphone surrounding the gearbox case. The main noise contribution is given by the 25th and 50th orders highlighted by two straight lines in the picture. These orders are linked to the first gearwheel since it features 25 teeth. Between 800 and 1300 Hz the noise levels are much higher. This is due to the excitation of specific structural modes by the first gearwheel. Figure 7 depicts the Sound Pressure Level (SPL) versus the machine RPM automatically extracted by Actran s WaterfallViewer from the plot of 6. This allows to better understand the impact of the different orders on the acoustic performance. Indeed, at low machine rotational speed the 50th order has a major contribution to the radiated noise, whereas the 25th mainly impacts the system at higher rotational speed. Conclusions Advances in the integration of CAE technologies enable a reduction of development time and resources. This article provides an example of these benefits by illustrating how the integration Adams and Actran improves the workflow for CAE engineers. Specifically, multibody dynamic and acoustic time domain analyses are integrated into Adams environment enabling MBD engineers to perform preliminary acoustic performance evaluations of their products. These evaluations also include the investigation of the noise quality thanks to the generation of audio files. Finally, and only on most relevant cases, advanced post-processing can be performed by acoustic engineers in Actran s environment. u Volume V - Summer

14 CO-SIMULATION SPOTLIGHT MULTIBODY DYNAMICS - NONLINEAR FEA CO-SIMULATION Evaluating Suspension Components Earlier in Design Volvo Car Looks Into New Technology to Simulate Complex Load Cases Based on an interview with Anders Wirje, Technical Expert at Endurance Attribute & Chassis CAE Dept,, Volvo Avehicle might be subjected to misuse, peak load or strength events such as driving over a curb or skidding against a curb a few times during its life. These durability load cases play a major role in the product development process since they potentially drive the design for several components. At Volvo, the driving over a curb and skid against a curb strength events are classified into two categories, Level 1 and 2. Level 1 represents extreme customer usage and the requirement is that all functions remain intact with no visible or noticeable deformation of any component of the vehicle. Level 2 covers customer misuse and a certain amount of damage is accepted with a safe failure mode. Structural deformations are acceptable but there should be no separation or breakage. For level 2 it is desirable that a predetermined inexpensively replaceable component deforms and protects neighboring components, a design principle known as chain of failure. Challenge The capability to perform peak load simulation with a high level of confidence is of great importance to setting the design loads for components and studying vehicle behavior in these events. Volvo uses Adams multibody dynamics software to simulate Level 1 load cases for driving over a curb and skidding against a curb. The components of interest are modeled as linear flexible bodies in Adams. This allows for linear material response for flexible bodies so this method is only valid up to small plastic strains which is a good fit for Level 1 load cases. On the other hand, Level 2 load cases involve plasticity and buckling of flexible bodies for which there has not been a way in Adams to simulate with sufficient levels of accuracy up to now. The skid against a curb load case is verified with physical testing with a known mass hitting the vehicle at a specified velocity and impact angle. These tests require prototype hardware that is expensive to build and only available later in the product development cycle. We wanted the capability to simulate Level 2 load cases in order to be able to evaluate design of suspension components earlier in the development cycle without having to build hardware for each design alternative, said Anders Wirje, Technical Expert CAE Durability at Volvo. Figure 1: Physical testing of skid against a curb load case Solution/Validation MSC recently introduced the Adams-Marc co-simulation capability that makes it possible for the first time to include geometrically and materially nonlinear structural behavior in multibody dynamics simulation. Any Adams model and any Marc model can be used in co-simulation with this tool. Post processing is done separately, Adams results in Adams and Marc results in the Marc postprocessor, or using Computational Engineering International s (CEI Inc.) EnSight post-processor which can import both Adams and Marc results. When setting up the co-simulation model for the skid against curb load case, the Marc model contains the lower control arm and bushings connecting the LCA to the subframe whereas the rest of the half-vehicle model are included in the Adams/Car model. Due to the extreme nature of a peak load event, component modeling is absolutely critical to simulation accuracy. All components have to be described within their full range of excitation. Key components and behavior to model include: Contacts between curb and tire & between curb and rim Elastomers, i.e. bushings Camber stiffness of the suspension Flexibility and plasticity/buckling of structural components Adams runs a dynamics analysis while Marc runs a quasi-static analysis which means that mass and inertia of the component is not accounted for. It would also be possible to run a transient analysis in Marc that would take mass effects into account. Adams leads the co-simulation and then feeds its results to Marc. Marc interpolates the Adams results to catch up and passes the results to Adams which extrapolates them in taking the next step. The simulated event has a duration of 0.7 seconds in clock time. The communication interval is 5e-4 seconds in clock time. The 10 MSC Software

15 total simulation time was a very reasonable 40 minutes on a Dell laptop with 16 Gigabytes of RAM and a 2.7 GHz CPU. The Adams Marc co-simulation of the Volvo S80 front suspension accurately predicted the behavior of a Level 2 skid against a curb load case. The low velocity impact (Level 1) and high velocity impact (Level 2) cases showed the same behavior as the physical tests. Results/Benefits The ability to accurately simulate Level 2 load cases will make it possible to substantially improve the product development process. From the early stages of the development process, we will be able to evaluate the performance of alternative designs in terms of their performance under Level 2 loads, Wirje said. The ability to quickly and easily look at alternatives at a time when we are not locked into any particular approach should make it possible to meet performance requirements with a lighter suspension that can improve the fuel economy of the vehicle. At the same, we should be able to reduce the cost and time involved in suspension development by performing product development more accurately from the beginning so fewer prototype verification cycles are required. Of course, full physical verification will be performed at the end of the project. About Volvo Car Group Volvo Car Group manufactures and markets sport utility vehicles, station wagons and sedans. Sales for 2014 hit a record of 465,866 cars, up 8.9 percent from Volvo Cars has been under the ownership of Zhejiang Geely Holding of China since u The ability to quickly and easily look at alternatives at a time when we are not locked into any particular approach should make it possible to meet performance requirements with a lighter suspension that can improve the fuel economy of the vehicle. Results of Adams-Marc co-simulation of Level 1 skid against curb event show no buckling or plasticity Strain mapped onto lower control arm in Level 2 skid against curb event Results of Adams-Marc co-simulation of Level 2 skid against curb event shows buckling and plastic deformation, matching physical testing results Close-up view of Adams-Marc co-simulation of Level 2 skid against curb event Lateral force on front bushing based on linear elastic simulation (blue trace) and fully non-linear Marc component (red trace) Volume V - Summer

16 CO-SIMULATION SPOTLIGHT MULTIBODY DYNAMICS - NONLINEAR FEA CO-SIMULATION System Analysis 15x Faster with Co-Simulation Litens Automotive Group achieves 90% reduction in computation time Based on an interview with Dr. Steve Jia, Chief Engineer, Litens Automotive Group Litens Automotive Group s patented TorqFiltr torque modulator uses an arc spring isolator mechanism to decouple the accessory drive system inertia from the engine torsional vibrations. The Litens torque modulator controls the system resonant frequency by tuning the spring stiffness to the system inertia. Because the spring stiffness is softer than traditional rubber isolators, vibrations from the engine are mostly absorbed before being transmitted to the accessory drive belt. This results in isolation of all components in the accessory drive, and any accessory drive resonance has very small peak amplitudes, since there is very little excitation. The product is dimensionally rather small, but incorporates a complex mechanism consisting of a series of components that transmit power to each other through complicated frictional contacts rather than fixed connections. This device provides an enormous design challenge, said Dr. Steve Jia, Chief Engineer for Litens Automotive Group. We need to fully understand the 12 MSC Software behavior of the design under dynamic loading conditions. The product must be customized to deliver optimal performance for many different automotive engines. In the past, this involved a time-consuming and expensive trial and error process. Challenge Litens developed the ability to accurately simulate the operation of its torque modulator including how the design behaves, how components move and react against each other, and what happens under dynamic loading conditions with MSC Marc nonlinear finite element analysis software. Simulation provides substantial cost savings by accurately predicting performance of a proposed design without the considerable expense and lead time required to build and test a prototype. However, the computational resource requirements are considerable because a nonlinear finite element analysis is performed on each component. Time to perform a typical simulation is 30 hours, which limits the degree to which nonlinear analysis can be used in the design process. We were looking for an approach that would allow us to simulate the performance of our torque modulators, including material and geometric nonlinearities, in a fraction of the time so that we could integrate advanced nonlinear analysis into the design process, Dr. Jia said. We had the idea of combining multibody dynamics (MBD) simulation at the system level with nonlinear finite element analysis at the component level for components with large deformation to achieve a fast solution and accurate results. MBD software has previously been integrated with linear FEA software, but not with nonlinear FEA, which is needed to provide accurate results for components with large deformations and material nonlinearities, such as the right and left side springs used in the torque modulator. Solution/Validation MSC is the leader in nonlinear analysis with Marc and the leader in MBD software with Adams, so they were the obvious choice

17 to approach with our request to integrate these two technologies, Dr. Jia said. MSC engineers coupled Marc and Adams so that the interaction between the motion behavior in Adams and the nonlinear behavior in Marc is taken into account in the simulation at both the system and component level and solved at each integration time step. Deflections calculated by Adams are taken into account at each time step in Marc and dynamic loading conditions are transferred from Marc to Adams. Marc determines stress and deformation at the component level with geometric, material, and contact nonlinearities taken into account. The Adams-Marc co-simulation capability was introduced in a beta release of Adams The beta release was validated on the Litens torque modulator before the software was released to the general public in Adams Results Litens CAE engineers set up the typical simulation so that only the left and right springs are modeled as flexible bodies in Marc and all other components are modeled as rigid bodies. Six contact points are established between the shell of the torque modulator and the springs, and these points are used by Adams to provide displacements to Marc, and by Marc to provide forces back to Adams. Under these conditions, Adams-Marc co-simulation analyzes the torque modulator in only two hours, 1/15 of the time required for Marc simulation. A small difference of 10% in results was seen with co-simulation, and this was expected since normal Marc simulation analyzes all components as flexible bodies while the co-simulation models most components as rigid bodies. The Marc simulations have previously been found to be very close to physical measurements. The cosimulation results for key values, such as the inner drive angle as a function of input torque, were found to vary by less than the 10% from the Marc simulation over two revolutions of the input shaft. This small difference in results is acceptable considering the dramatic reduction in computation time provided by co-simulation, Dr. Jia said. This technology will make it The Litens torque modulator controls the system resonant frequency by tuning the spring stiffness to the system inertia. possible for the first time to utilize advanced nonlinear FEA as an integral part of the design process. We see this advancement as similar in significance to the advancement several decades ago in computing power which made it possible to integrate FEA into the design process. It is expected that Adams-Marc co-simulation in the early stages of the design process to evaluate different design alternatives will significantly speed up the design process. Once we find a design that looks promising, we will run a more accurate Marc simulation to validate its performance. About Litens Car Group Litens is a global organization serving the automotive market with high quality service and products for power transmission systems. Litens was the first company to develop and produce in volume an automotive automatic tensioner and single belt accessory drive. After 35 years, Litens has established its global leadership in automotive belt drive systems and component design applications. The company is engaged in the development of innovative products to provide its global customer base with unique engineered solutions to vehicle performance and NVH challenges. u Comparison of dynamic spring load for left spring for Marc simulation vs. Adams-Marc co-simulation Adams Model of the Center Drive and Marc Model of the Two Springs The Adams-Marc cosimulation capability more than satisfies our guideline of reasonable results in a reasonable time. With up to a 90% reduction in computation time, optimization using advanced nonlinear FEA becomes practical. Such development provides a great benefit and is crucial for our product development and we are proud to work together with MSC in advancing the technology. Volume V - Summer

18 CO-SIMULATION SPOTLIGHT MULTIBODY DYNAMICS - CONTROLS CO-SIMULATION Tackling Conflicting Performance Requirements Ford Leverages Adams FMI Co-Simulation Method to Optimize Tradeoff between Fuel Economy and NVH By Mario Felice & Jack Liu of Ford Motor Company & Wulong Sun of MSC Software Noise/vibration/harshness (NVH) and fuel economy often must be traded off against each other during the vehicle design process. For example, lugging is a condition that typically occurs when the vehicle is in high gear with an engine speed of below 2000 rpm. When the driver steps on the gas pedal under these conditions, the engine struggles to give motion to the vehicle while generating relatively little torque so acceleration is low. Lugging produces high levels of low frequency inputs because of the low firing frequency at low engine speeds and high loads. These low frequency inputs are frequently experienced by the driver and passenger as seat track vibration, steering wheel vibration and interior cabin boom sound. One of the primary methods by which engineers attempt to control lugging is through the torque converter which transmits and amplifies the torque from the engine to the transmission using fluid coupling. The torque converter consists of a pump, turbine, impeller and stator contained within a cavity filled with transmission fluid in addition to a lockup clutch and damper assembly. The clutch is electronically controlled to provide the desired level of slip. When required, the clutch locks up and provides a direct connection between the engine and transmission, resulting in near 100% efficiency and the best fuel economy. In lock-up mode, engine torque fluctuation is transmitted directly to the transmission, potential causing the drivetrain to generate vibration and noise. Slipping the torque converter increases damping,reducing sensitivity of the driveline vibration to the engine torque excitation and improvingnvh performance. On other hand, slipping increases losses due to fluid coupling and clutch friction which decreases fuel economy. Challenge When developing a new vehicle model, engineers are responsible for meeting a wide variety of often conflicting performancetargets. Fuel economy and NVH are two of the most important categories of targets. With regards to lugging, NVH engineers are typically responsible for holding torsional vibration amplitudes at the transmission output shaft below a target value. The NVH team naturally would prefer a large amount of slip in order to help meet their targets while the team responsible for fuel economy would like slip to be as low as possible to meet their targets. Up to now it has not been possible to determine torsional vibration amplitudes with high levels of accuracy until a prototype vehicle is built and tested in the late stages of the product development process. However, at this late stage, the design is frozen and changes are quite expensive and could potentially delay production. Ford was looking for a method to simulate the effects of different torque converter designs so that engineers could make intelligent tradeoffs upfront in the design and development stages. Drivetrain model Adams and AMESim FMI co-simulation Torque converter assembly 14 MSC Software

19 We ran the model for different values of desired slip rpm across a broad range of engine rpm. The simulation results showed that a slip of 30 rpm or lower would fail to meet the NVH target while a slip of 40 rpm or greater would meet the target. The simulation showed that 40 rpm slip was the optimal value that would meet the NVH target and would result in the best trade off with fuel economy. Solution/Validation Ford engineers addressed this challenge by taking advantage of a new capability of MSC Software s Adams to support the Functional Mock-Up Interface (FMI) tool independent open standard for model exchange or cosimulation. The FMI standard makes it possible to create a virtual product from a set of models of the physical laws and control systems assembled digitally. The FMI instance of a model is called a Functional Mock-Up Unit (FMU). An FMU is a formatted file containing an XML formatted model description file, dynamic link libraries and model data files. FMI can be used for model exchange or co-simulation. The Adams FMI support extends the Adams/ Controls Co-simulation support of Matlab and Easy5 to all software utilizing the FMI Cosimulation standard. In this case, Ford engineers used an Adams 3D drivetrain and full vehicle model as the co-simulation master with an AMESim 1D converter slip controller model as the cosimulation slave with the goal of optimizing converter slip to meet the vehicle lugging NVH target while maximizing fuel economy. A drivetrain model was created in Adams/ Driveline including an I4 Gasoline Turbocharged Direct Injection (GTDI) engine with three mounts, a torque converter with a lockup clutch, a six-speed gearbox with internal shafts and planetary gear sets, and a front driveline with differential, link-shafts, halfshafts, constant velocity joints and wheels. The driveline model was incorporated into a full vehicle model using Adams/Car. The vehicle model includes the chassis, suspension, steering, brake and wheel subsystems. The AMESim torque converter model is a Torsional vibration at transmission output shaft vs. engine rpm vs. slip rpm proportional-integral-derivative (PID) controller that provides the normal force on the converter clutch based on the difference between the actual slip and the desired slip. Results We ran the model for different values of desired slip rpm across a broad range of engine rpm, Mario Felice said. The simulation results showed that a slip of 30 rpm or lower would fail to meet the NVH target while a slip of 40 rpm or greater would meet the target. The simulation showed that 40 rpm slip was the optimal value that would meet the NVH target and would result in the best trade off with fuel economy. Engineers further studied the reduction in torsional vibration amplitudes generated by the clutch damper behavior and the torque converter slip. They also compared vibration at the steering wheel and seat track with 0 rpm and 40 rpm slip. The results showed that steering wheel and seat track vibration are drastically reduced by slipping the torque converter. Next steps will include increasing the sophistication of the torque converter model by modeling the hydraulic system to provide more accurate predictions of normal force as a function of time, Felice said. We also plan to validate the model with physical testing results. Then we will integrate the co-simulation into the design process so that the torque converter design can be optimized early in the product development cycle. About Ford The Ford Motor Company is an American multinational automaker that sells automobiles and commercial vehicles under the Ford brand and luxury cars under the Lincoln brand. u Steering Wheel and Seat Track Vibration are drastically reduced by slipping Torque Converter Volume V - Summer

20 CO-SIMULATION SPOTLIGHT MULTIBODY DYNAMICS - NONLINEAR FEA CO-SIMULATION Simulations give insight into Bedsore Problems MSC Co-Sim Technology Combines with EnSight 3D Visualization to Solve Bedsore Mystery By Ms. Kara Gray, CEI & Mark Carlson, MSC Software Each year, an estimated 1 million people suffer from painful bedsores in U.S. hospitals across the country. These wounds are the result of long-term confinement to a bed or wheelchair and often become seriously infected or develop gangrene. Not only are bedsores incredibly painful, but they can also be deadly, linked to a four-fold increase in death, with a hospital mortality rate of percent. Compounding the problem, patients who develop bedsores also experience a five-time longer hospital stay, putting them at much greater risk of developing other ailments. Then, of course, there are financial implications: conservative estimates peg the cost of bedsores in U.S. hospitals at $55 billion per year. (All sources: leedergroup.com/bulletins/bed-sores). Finding a way to prevent bedsores before they start is a high priority for hospitals, nursing home and long-term care facilities, as well as bed manufacturers. Conventional means of studying possible solutions typically involve long prototyping processes and the use of human test subjects, who are asked to lie in a bed for an extended period to see if they develop a bedsore. Instead, MSC Software s Senior Engineer Mark Carlson and his team have developed a simulation test bed both literally and figuratively for assessing the impact of potential bed designs on bedsore formation in a matter of hours instead of months, with absolutely no risk to human health. The simulation combines the non-linear finite element solution capabilities in MSC Marc with the multi-body dynamics analysis power of MSC Adams, and the 3D post-processing visualization provided by EnSight from CEI. The analysis has been able to uncover critical, previously unattainable insights into the bedsore problem. This helps equipment manufacturers build better beds that can help prevent bedsores from forming in the first place. More than Skin Deep One of the critical challenges in studying bedsore development is understanding how, where and why they develop. Anecdotally, Carlson and his team knew that the buttocks and heels are the primary locations for bedsore formation. Bed manufacturers have been experimenting for years with different types of bed surfaces, foam materials, positioning/ angling and other parameters to help better distribute the stresses caused by pressure and gravity across the body. The problem is, conventional testing typically involves two methods, which have some limitations. First, manufacturers ask human test subjects to lie on a pressure sensitive pad, which indicates how the contact patches manifest externally, on the surface of the skin. Researchers have long theorized that bedsores are more than just a surface problem they actually manifest under skin, deep in the tissues of the flesh, muscles and even bone interfaces. Second, lab tests using body part molds in a compression test machine can study the forces applied by those parts onto the bed, but only for those specific, individual parts just the heel or the torso, for example. This kind of test makes no consideration for the changes, sometimes dramatic, which could occur when entire human bodies of varying sizes and anthropometric characteristics are positioned across the entire bed. Marc/Adams Co-Sim Reveals Hidden Insights To study the problem more holistically, Carlson and team developed an advanced co-simulation solution that not only allowed researchers to study the problem more thoroughly, but also much faster, to accelerate material and equipment design innovation, testing and market delivery. Carlson began with Adams to simulate the rigid component geometry of the human body, using the Life Mod plugin ( lifemodeler.com/products/lifemod/) from Life Modeler of San Clemente, Calif., to model the anthropometric data for various parts, sizes and characteristics of the human body from the pre-loaded Life Modeler geometry database. Adams was able to simulate the effects of bed settling due to gravity across the fifteen different body segments, accounting for accurate range of motion calculations, as well as the other complex dynamics and kinematics present in the various human joints. But, gravity settling is only part of the 16 MSC Software