Product-process interaction modeling of composite structures using As-Built information

Transcription

1 FASERINSTITUT BREMEN e.v. (FIBRE) Product-process interaction modeling of composite structures using As-Built information Christian BRAUNER 1, Andrea MIENE 1, Michael BRUYNEEL², Frederic PASCON², Axel S. HERRMANN 1 Contact: Christian Brauner tel.: (0) [email protected] March 2015

2 Agenda Introduction Online Process Monitoring Preforming / Draping Online Process Monitoring Resin arrival / Curing Cure dependent material modelling Results of a As built analysis Conclusion

3 Motivation Material variability Variationen during preforming / draping Variation of process parameters like pressure, temperature, time Homogenization Draping Injection As Built part performance Structural analysis Curing Warpage/residual stress Part quality 3

4 Agenda Introduction Online Process Monitoring Preforming / Draping Online Process Monitoring Resin arrival / Curing Cure dependent material modelling Results of a As built analysis Conclusion

5 Prefoming Monitoring Objectives Foreign objects Fibre orientations Patch position Gaps, Overlays Thickness Methods Keyence LJ-V7200 laser displacement sensor CCD camera together with the FIBRE light dome

6 Prefoming Monitoring Application test case Cutting Draping of first layer, thickness measurement Measurement of fibre orientation Last Layer and vacuum bag setup

7 Prefoming Monitoring Result: thickness measurement 1Layer 2 & 3 Layer 4 Layer Deviation: two Overlaps

8 Prefoming Monitoring Result: thickness measurement projected on a FE mesh Thickness values projected on a FE shell mesh

9 Prefoming Monitoring Result: Fibre orientation measurement Fibre orientation

10 Agenda Introduction Online Process Monitoring Preforming / Draping Online Process Monitoring Resin arrival / Curing Cure dependent material modelling Results of a As built analysis Conclusion

11 Cure Monitoring Objectives Resin arrival Cure time and cure evolution Cover First time right and process control aspects Methods Measurement of dielectric resin properties Measurement of resistance changes Measurement of ultrasonic sound properties Available sensors

12 OPM - Cure Monitoring Curing at 100 C Post Curing at 180 C Noise? Resin arrival Curing Postcuring

13 Agenda Introduction Online Process Monitoring Preforming / Draping Online Process Monitoring Resin arrival / Curing Cure dependent material modelling Results of a As built analysis Conclusion

14 Simulation Approach Simulation strategy : Sequential coupled thermo mechanical analysis Advantages of sequential coupling: Dependency from thermal to mechanical but not reveres Computational cheap Flexible coupling, possibility to use different discretisation / mesh

15 Description of the methode Structure of the method Load State Variables Calculate Degree of cure, Tg Calculate Matrix stiffness Calculate ply properties Asssemble stiffness matrix Calculate total strain Calculate stress Save State Variables - Output 17

16 Description of the methode Characterization of the cure kinetics of RTM6 resin using DSC- mesurements Load State Variables Cure kinetic approach of Kamal / Sourour is used Calculate Degree of cure, Tg DiBenedetto equation to determine the glass transition temperature 18

17 Description of the methode Dependency of the matrix modulus Degree of cure Load State Variables Calculate Degree of cure, Tg Calculate Matrix stiffness Nonlineare approch based on Rehometer mesurements 19

18 Description of the methode Homogenization of the ply properties by Hashin/Hill Load State Variables Calculate Degree of cure, Tg Ply properties Transverse to the fibre direction Calculate Matrix stiffness In fibre direction Calculate ply properties Assemble stiffness matrix Orthotropic stiffness matrix 20

19 Description of the methode Model development viscoelasticity Load State Variables Characterization using DMA relaxation measurements Calculate Degree of cure, Tg Calculate Matrix stiffness Calculate ply properties Asssemble stiffness matrix Calculate total strain Calculate stress Modified incremental linear viscoelastic approach of Zocher Math. closed form modeling of the master curve Using extended shift factors Incremental stress formulation extended shift factors 21

20 Description of the methode Model development viscoelasticity Load State Variables Calculate Degree of cure, Tg Calculate Matrix stiffness Transfer of the viscoelastic matrix dependency using homogenization approach of Meder RT 180 C Calculate ply properties Asssemble stiffness matrix E1 [MPa] E1 [MPa] Calculate total strain Time[min] Time [min] Calculate stress Relaxations spectrum in fibre direction E2 [MPa] E2 [MPa] Time [min] Time [min] Relaxations spectrum in transverse direction 22

21 Agenda Introduction Online Process Monitoring Preforming / Draping Online Process Monitoring Resin arrival / Curing Cure dependent material modelling Results of a As built analysis Conclusion

22 Results of a As built analysis Result: Temperature & Degree of cure

23 Results of a As built analysis Result: Development of engineering constants

24 Results of a As built analysis Result: Stress transverse to the fibre direction

25 Results of a As built analysis Result: Process induced deformation on As-Planned and As-Build configuration Increase of warpage by 13% by including overlays

26 Conclusion Efficient simulation strategy to analyse process induced distortions and residual stresses Transient analysis of the process to study effects of the process parameters Enhancement from a cure dependent viscoelastic material (Svanberg) to a cure dependent fibre volume dependent viscoelastic material description Full characterisation of the used materials with focus on the relaxation effect Coupling to Online Process Monitoring to feedback As-Built information to ensure reliable simulation models

27 FASERINSTITUT BREMEN e.v. (FIBRE) Thank you for your attention Acknowledgement The authors are grateful for the financial support provided by the European Commission within the framework FP7 of research project ECOMISE. Contact: Christian Brauner tel.: (0) [email protected]