# Notes on Ultrasonic Experiments

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Notes on Ultrasonic Experiments Material Properties and Sound Waves Sound travels at different speeds in different materials. This is because the mass of the atomic particles and the force constants are different for different materials. The mass of the particles is related to the density of the material, and the interatomic force constant is related to the elastic constants of a material. The general relationship between the speed of sound in a solid and its density and elastic constants is given by the following equation: Where V is the speed of sound, C is the elastic constant, and is the material density. This equation may take a number of different forms depending on the type of wave (longitudinal or shear) and which of the elastic constants that are used. The typical elastic constants of a materials include: Young's Modulus, E: a proportionality constant between uniaxial stress and strain. Poisson's Ratio, : the ratio of radial strain to axial strain Bulk modulus, K: a measure of the incompressibility of a body subjected to hydrostatic pressure. Shear Modulus, G: also called rigidity, a measure of a substance's resistance to shear. Lame's Constants, and : material constants that are derived from Young's Modulus and Poisson's Ratio. When calculating the velocity of a longitudinal wave, Young's Modulus and Poisson's Ratio are commonly used. When calculating the velocity of a shear wave, the shear modulus is used. It is often most convenient to make the calculations using Lame's Constants, which are derived from Young's Modulus and Poisson's Ratio. It must also be mentioned that the subscript ij attached to C in the above equation is used to indicate the directionality of the elastic constants with respect to the wave type and direction of wave travel. In isotropic materials, the elastic constants are the same for all directions within the material. However, most materials are anisotropic and the elastic constants differ with each direction. For example, in a piece of rolled aluminum plate, the grains are elongated in one direction and compressed in the others and the elastic constants for the longitudinal direction are different than those for the transverse or short transverse directions. 1

2 Examples of approximate compressional sound velocities in materials are: 1020 steel cm/microsecond Cast iron cm/microsecond. Examples of approximate shear sound velocities in materials are: 1020 steel cm/microsecond Cast iron cm/microsecond. Acoustic Impedance Sound travels through materials under the influence of sound pressure. Because molecules or atoms of a solid are bound elastically to one another, the excess pressure results in a wave propagating through the solid. The acoustic impedance (Z) of a material is defined as the product of its density () and acoustic velocity (V). Z = V Acoustic impedance is important in 1. the determination of acoustic transmission and reflection at the boundary of two materials having different acoustic impedances. 2. the design of ultrasonic transducers. 3. assessing absorption of sound in a medium. 2

3 Ultrasonic waves are reflected at boundaries where there is a difference in acoustic impedances (Z) of the materials on each side of the boundary. (See preceding page for more information on acoustic impedance.) This difference in Z is commonly referred to as the impedance mismatch. The greater the impedance mismatch, the greater the percentage of energy that will be reflected at the interface or boundary between one medium and another. The fraction of the incident wave intensity that is reflected can be derived because particle velocity and local particle pressures must be continuous across the boundary. When the acoustic impedances of the materials on both sides of the boundary are known, the fraction of the incident wave intensity that is reflected can be calculated with the equation below. The value produced is known as the reflection coefficient. Multiplying the reflection coefficient by 100 yields the amount of energy reflected as a percentage of the original energy. Since the amount of reflected energy plus the transmitted energy must equal the total amount of incident energy, the transmission coefficient is calculated by simply subtracting the reflection coefficient from one. Refraction and Snell's Law Refraction takes place at an interface due to the different velocities of the acoustic waves within the two materials. The velocity of sound in each material is determined by the material properties (elastic modulus and density) for that material. Snell's Law describes the relationship between the angles and the velocities of the waves. Snell's law equates the ratio of material velocities V 1 and V 2 to the ratio of the sine's of incident ( ) and refracted ( ) angles, as shown in the following equation. Where: V L1 is the longitudinal wave velocity in material 1. V L2 is the longitudinal wave velocity in material 2. 3

4 In the diagram, the incident longitudinal wave (V L1 ), a reflected longitudinal wave (V L1' ) and refracted longitudinal waves (V L2 ) are shown. The reflected wave is reflected at the same angle as the incident wave because the two waves are traveling in the same material, and hence have the same velocities. Mode Conversion When sound travels in a solid material, one form of wave energy can be transformed into another form. For example, when a longitudinal waves hits an interface at an angle, some of the energy can cause particle movement in the transverse direction to start a shear (transverse) wave. Mode conversion occurs when a wave encounters an interface between materials of different acoustic impedances and the incident angle is not normal to the interface. Snell's Law holds true for shear waves as well as longitudinal waves and can be written as follows. Where: V L1 is the longitudinal wave velocity in material 1. V L2 is the longitudinal wave velocity in material 2. V S1 is the shear wave velocity in material 1. V S2 is the shear wave velocity in material 2. It can be seen that when a wave moves from a slower to a faster material, there is an incident angle which makes the angle of refraction for the longitudinal wave 90 degrees. This is known as the first critical angle and all of the energy from the refracted longitudinal wave is now converted to a surface following longitudinal wave. This surface following wave is sometime referred to as a creep wave and it dampens out very rapidly with increasing distance. Beyond the first critical angle, only the shear wave propagates into the material. For this reason, most angle beam transducers use a shear wave so that the signal is not complicated by having two waves present. In many cases there is also an incident angle that makes the angle of refraction for the shear wave 90 degrees. This is known as the second critical angle and at this point, all of the wave energy is reflected or refracted into a surface following shear wave or shear creep wave. Slightly beyond the second critical angle, surface waves will be generated. 4

5 Normal Beams When a transducer (usually a piezoelectric sensor) is placed in contact with a material, longitudinal waves are transmitted into the material. If the same transducer is used to receive the reflected/scattered waves, the configuration is termed pulse-echo method. If a separate transducer is used to receive the reflected/scattered waves, the configuration is termed pitch-catch method. Oscilloscope traces of pulses Angle Beams Wedges are typically used to introduce a refracted shear wave into the test material. The angle of refraction is only accurate for a particular material, which is usually steel. Transmitter Receiver Signal Characteristics Normally, when a signal is measured with an oscilloscope, it is viewed in the time domain (vertical axis is amplitude or voltage and the horizontal axis is time). For many signals, this is the most logical and intuitive way to view them Time Domain Frequency Domain (Magnitude) 5

6 The frequency domain display shows how much of the signal's energy is present as a function of frequency. For a simple signal such as a sine wave, the frequency domain representation does not usually show us much additional information. However, with more complex signals, such as the response of a broad bandwidth transducer, the frequency domain gives a more useful view of the signal. Fourier theory says that any complex periodic waveform can be decomposed into a set of sinusoids with different amplitudes, frequencies and phases. The process of doing this is called Fourier Analysis, and the result is a set of amplitudes, phases, and frequencies for each of the sinusoids that makes up the complex waveform. Adding these sinusoids together again will reproduce exactly the original waveform. A plot of the frequency or phase of a sinusoid against amplitude is called a spectrum. Lab activity: You are provided solid media of several types (metal, granite, wood, glass etc). You are to determine the longitudinal and shear wave speeds in these materials and estimate the various elastic moduli, Poisson ratio of these materials. The longitudinal wave speed is to be determined using the pulse-echo mode of operation. The shear wave speed is to be determined using the through transmission mode of operation. 1. With normal beam transduction in the pulse-echo method, estimation of longitudinal wave speed from distance and time of flight data. 2. With two angle beam transducers in the through-traqnsmission mode, estimation of shear wave speed from distance and time of flight data. 3. With angle beam transducers in the pitch-catch mode, checking for mode conversion. 4. Estimation of elastic moduli and Poisson ratio with longitudinal and shear wave speeds (given density) You are to familiarize yourself with Snell s laws associated with plane waves, critical angle calculations, acoustic impedances, and impedance mismatch. Useful information: Longitudinal wave speed in wedge material: 2700 m/s Longitudinal wave speed in steel: 5890 m/s Shear wave speed in steel: 3240 m/s Angle of refraction produced by the wedge in steel: 45 6

7 Generation of Ultrasound Remember the tuning fork? It was used to produce sound waves at a specific frequency. The tuning fork was made to resonate at a specific frequency. You also recall that the sound was heard long after the tuning fork was struck. In other words, the tuning fork was lightly damped. To generate ultrasound, typically a piezo-electric crystal (such as quartz that you may have found in quartz clocks) is used. The dimensions of the crystal are chosen to let it resonate at a specific frequency. You will see in the lab transducers that have these resonating crystals and something more. Applied Voltage Sound pressure (damped) Received Voltage Figure 1 On the left of Figure 1, we see a typical transducer with mechanisms for damping which will result in a short duration sound pulse to be generated. On the right of Figure 1, a schematic shows the sound generation (damped quartz crystal on the left), sound propagation in a medium (water in this case) and sound reception (another damped quartz crystal). The sequence of what happens when a short voltage pulse is applied to a damped crystal is indicated alongside (top trace). The sound pressure pulse that propagates in water (the medium in this case) is shown as the middle trace. What we see on the oscilloscope is what is depicted as the received voltage (bottom trace).

### Acoustic Velocity, Impedance, Reflection, Transmission, Attenuation, and Acoustic Etalons

Acoustic Velocity, Impedance, Reflection, Transmission, Attenuation, and Acoustic Etalons Acoustic Velocity The equation of motion in a solid is (1) T = ρ 2 u t 2 (1) where T is the stress tensor, ρ is

### BIOMEDICAL ULTRASOUND

BIOMEDICAL ULTRASOUND Goals: To become familiar with: Ultrasound wave Wave propagation and Scattering Mechanisms of Tissue Damage Biomedical Ultrasound Transducers Biomedical Ultrasound Imaging Ultrasonic

### DESIGN AND EVALUATION OF PROBE WITH THREE DEGREE- OF-FREEDOM FOR NON-DESTRUCTIVE TEST USING THREE- DIMENSIONAL FINITE ELEMENT METHOD

DESIGN AND EVALUATION OF PROBE WITH THREE DEGREE- OF-FREEDOM FOR NON-DESTRUCTIVE TEST USING THREE- DIMENSIONAL FINITE ELEMENT METHOD Masafumi Aoyanagi Graduate School of Systems and Information Engineering,

### Introduction to acoustic imaging

Introduction to acoustic imaging Contents 1 Propagation of acoustic waves 3 1.1 Wave types.......................................... 3 1.2 Mathematical formulation.................................. 4 1.3

### Ultrasonic Wave Propagation Review

Ultrasonic Wave Propagation Review Presented by: Sami El-Ali 1 1. Introduction Ultrasonic refers to any study or application of sound waves that are higher frequency than the human audible range. Ultrasonic

### 10ème Congrès Français d'acoustique Lyon, 12-16 Avril 2010

ème Congrès Français d'acoustique Lyon, -6 Avril Finite element simulation of the critically refracted longitudinal wave in a solid medium Weina Ke, Salim Chaki Ecole des Mines de Douai, 94 rue Charles

### Experiment 1: SOUND. The equation used to describe a simple sinusoidal function that propagates in space is given by Y = A o sin(k(x v t))

Experiment 1: SOUND Introduction Sound is classified under the topic of mechanical waves. A mechanical wave is a term which refers to a displacement of elements in a medium from their equilibrium state,

### Handbook on the Ultrasonic Examination. Austenitic Welds

Handbook on the Ultrasonic Examination Austenitic Welds The International Institute of Welding Edition Handbook On the Ultrasonic Examination of Austenitic Welds Compiled by COMMISSION V Testing, Measurement,

### An Introduction to Piezoelectric Transducer Crystals. Piezoelectric Materials and their Properties

An Introduction to Piezoelectric Transducer Crystals Piezoelectric Materials and their Properties Certain single crystal materials exhibit the following phenomenon: when the crystal is mechanically strained,

### INTERFERENCE OF SOUND WAVES

1/2016 Sound 1/8 INTERFERENCE OF SOUND WAVES PURPOSE: To measure the wavelength, frequency, and propagation speed of ultrasonic sound waves and to observe interference phenomena with ultrasonic sound waves.

### Scanning Acoustic Microscopy Training

Scanning Acoustic Microscopy Training This presentation and images are copyrighted by Sonix, Inc. They may not be copied, reproduced, modified, published, uploaded, posted, transmitted, or distributed

### 7.2.4 Seismic velocity, attenuation and rock properties

7.2.4 Seismic velocity, attenuation and rock properties Rock properties that affect seismic velocity Porosity Lithification Pressure Fluid saturation Velocity in unconsolidated near surface soils (the

### Stress Strain Relationships

Stress Strain Relationships Tensile Testing One basic ingredient in the study of the mechanics of deformable bodies is the resistive properties of materials. These properties relate the stresses to the

### Rock Bolt Condition Monitoring Using Ultrasonic Guided Waves

Rock Bolt Condition Monitoring Using Ultrasonic Guided Waves Bennie Buys Department of Mechanical and Aeronautical Engineering University of Pretoria Introduction Rock Bolts and their associated problems

### Overview of Topics. Stress-Strain Behavior in Concrete. Elastic Behavior. Non-Linear Inelastic Behavior. Stress Distribution.

Stress-Strain Behavior in Concrete Overview of Topics EARLY AGE CONCRETE Plastic shrinkage shrinkage strain associated with early moisture loss Thermal shrinkage shrinkage strain associated with cooling

### Electrical Resonance

Electrical Resonance (R-L-C series circuit) APPARATUS 1. R-L-C Circuit board 2. Signal generator 3. Oscilloscope Tektronix TDS1002 with two sets of leads (see Introduction to the Oscilloscope ) INTRODUCTION

### FXA 2008. UNIT G485 Module 4 5.4.3 Ultrasound. Candidates should be able to :

1 Candidates should be able to : ULTRASOUND Describe the properties of ultrasound. ULTRASOUND is any sound wave having a frequency greater than the upper frequency limit of human hearing (20 khz). Describe

### Acousto-optic modulator

1 of 3 Acousto-optic modulator F An acousto-optic modulator (AOM), also called a Bragg cell, uses the acousto-optic effect to diffract and shift the frequency of light using sound waves (usually at radio-frequency).

### 4.4 WAVE CHARACTERISTICS 4.5 WAVE PROPERTIES HW/Study Packet

4.4 WAVE CHARACTERISTICS 4.5 WAVE PROPERTIES HW/Study Packet Required: READ Hamper pp 115-134 SL/HL Supplemental: Cutnell and Johnson, pp 473-477, 507-513 Tsokos, pp 216-242 REMEMBER TO. Work through all

### Periodic Wave Phenomena

Name: Periodic Wave Phenomena 1. The diagram shows radar waves being emitted from a stationary police car and reflected by a moving car back to the police car. The difference in apparent frequency between

### PHYSICS 202 Practice Exam Waves, Sound, Reflection and Refraction. Name. Constants and Conversion Factors

PHYSICS 202 Practice Exam Waves, Sound, Reflection and Refraction Name Constants and Conversion Factors Speed of sound in Air œ \$%!7Î= "'!*7/>/

### 3.14 understand that light waves are transverse waves which can be reflected, refracted and diffracted

Light and Sound 3.14 understand that light waves are transverse waves which can be reflected, refracted and diffracted 3.15 use the law of reflection (the angle of incidence equals the angle of reflection)

### Data Communications Prof. Ajit Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture # 03 Data and Signal

(Refer Slide Time: 00:01:23) Data Communications Prof. Ajit Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture # 03 Data and Signal Hello viewers welcome

### Advancements in High Frequency, High Resolution Acoustic Micro Imaging for Thin Silicon Applications

Advancements in High Frequency, High Resolution Acoustic Micro Imaging for Thin Silicon Applications Janet E. Semmens Sonoscan, Inc. 2149 E. Pratt Boulevard Elk Grove Village, IL 60007 USA Phone: (847)

### Plate waves in phononic crystals slabs

Acoustics 8 Paris Plate waves in phononic crystals slabs J.-J. Chen and B. Bonello CNRS and Paris VI University, INSP - 14 rue de Lourmel, 7515 Paris, France chen99nju@gmail.com 41 Acoustics 8 Paris We

### APPLICATION NOTE ULTRASONIC CERAMIC TRANSDUCERS

APPLICATION NOTE ULTRASONIC CERAMIC TRANSDUCERS Selection and use of Ultrasonic Ceramic Transducers The purpose of this application note is to aid the user in the selection and application of the Ultrasonic

### A wave lab inside a coaxial cable

INSTITUTE OF PHYSICS PUBLISHING Eur. J. Phys. 25 (2004) 581 591 EUROPEAN JOURNAL OF PHYSICS PII: S0143-0807(04)76273-X A wave lab inside a coaxial cable JoãoMSerra,MiguelCBrito,JMaiaAlves and A M Vallera

### Indiana's Academic Standards 2010 ICP Indiana's Academic Standards 2016 ICP. map) that describe the relationship acceleration, velocity and distance.

.1.1 Measure the motion of objects to understand.1.1 Develop graphical, the relationships among distance, velocity and mathematical, and pictorial acceleration. Develop deeper understanding through representations

### PRODUCTION OF ULTRASONIC WAVE

ULTRASONICS Production of ultrasonics by magnetostriction and piezoelectric methods - acoustic grating -Non Destructive Testing - pulse echo system through transmission and reflection modes - A,B and C

### Waves Sound and Light

Waves Sound and Light r2 c:\files\courses\1710\spr12\wavetrans.doc Ron Robertson The Nature of Waves Waves are a type of energy transmission that results from a periodic disturbance (vibration). They are

### Crystal Optics of Visible Light

Crystal Optics of Visible Light This can be a very helpful aspect of minerals in understanding the petrographic history of a rock. The manner by which light is transferred through a mineral is a means

### Physics 9e/Cutnell. correlated to the. College Board AP Physics 1 Course Objectives

Physics 9e/Cutnell correlated to the College Board AP Physics 1 Course Objectives Big Idea 1: Objects and systems have properties such as mass and charge. Systems may have internal structure. Enduring

### Vibrational Analysis of Guitar Bodies

Vibrational Analysis of Guitar Bodies Eric W. Moon Department of Physics, University of Illinois at Urbana-Champaign ABSTRACT Understanding how a guitar vibrates could aid manufacturers in shaping the

### Lab Exercise 1: Acoustic Waves

Lab Exercise 1: Acoustic Waves Contents 1-1 PRE-LAB ASSIGNMENT................. 2 1-3.1 Spreading Factor: Spherical Waves........ 2 1-3.2 Interference In 3-D................. 3 1-4 EQUIPMENT........................

### STANDING WAVES & ACOUSTIC RESONANCE

REFERENCES & ACOUSTIC RESONANCE R.H. Randall, An Introduction to Acoustics, (Addison-Wesley, 1951), Sect. 7-1, 7-. A.B. Wood, A Textbook of Sound, (Bell & Sons, 1944), pp.179 et seq. Berkeley Physics Course,

### Ultrasonic Technique and Device for Residual Stress Measurement

Ultrasonic Technique and Device for Residual Stress Measurement Y. Kudryavtsev, J. Kleiman Integrity Testing Laboratory Inc. 80 Esna Park Drive, Units 7-9, Markham, Ontario, L3R 2R7 Canada ykudryavtsev@itlinc.com

### Piezoelectric Simulations

Piezoelectric Simulations Outline Overview Examples Relevant Products Useful Features Overview Industries Using Piezoelectric Devices Aerospace Oil & Gas Automotive Piezoelectric Devices MEMS Acoustics

### AP1 Waves. (A) frequency (B) wavelength (C) speed (D) intensity. Answer: (A) and (D) frequency and intensity.

1. A fire truck is moving at a fairly high speed, with its siren emitting sound at a specific pitch. As the fire truck recedes from you which of the following characteristics of the sound wave from the

### APPLICATION NOTE AP050830

APPLICATION NOTE AP050830 Selection and use of Ultrasonic Ceramic Transducers Pro-Wave Electronics Corp. E-mail: sales@pro-wave.com.tw URL: http://www.prowave.com.tw The purpose of this application note

### Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect

Objectives: PS-7.1 Physical Science Study Guide Unit 7 Wave properties and behaviors, electromagnetic spectrum, Doppler Effect Illustrate ways that the energy of waves is transferred by interaction with

### Mechanical Properties of Metals Mechanical Properties refers to the behavior of material when external forces are applied

Mechanical Properties of Metals Mechanical Properties refers to the behavior of material when external forces are applied Stress and strain fracture or engineering point of view: allows to predict the

### Chapter Outline. Mechanical Properties of Metals How do metals respond to external loads?

Mechanical Properties of Metals How do metals respond to external loads? Stress and Strain Tension Compression Shear Torsion Elastic deformation Plastic Deformation Yield Strength Tensile Strength Ductility

### Waves-Wave Characteristics

1. What is the wavelength of a 256-hertz sound wave in air at STP? 1. 1.17 10 6 m 2. 1.29 m 3. 0.773 m 4. 8.53 10-7 m 2. The graph below represents the relationship between wavelength and frequency of

### Lecture 11: Introduction to Constitutive Equations and Elasticity

Lecture : Introduction to Constitutive quations and lasticity Previous lectures developed the concepts and mathematics of stress and strain. The equations developed in these lectures such as Cauchy s formula

### Sonic Logging in Deviated Boreholes of an Anisotropic Formation: Laboratory Study

Sonic Logging in Deviated Boreholes of an Anisotropic Formation: Laboratory Study Zhenya Zhu, Shihong Chi, and M. Nafi Toksöz Earth Resources Laboratory Dept. of Earth, Atmospheric, and Planetary Sciences

### Acceleration levels of dropped objects

Acceleration levels of dropped objects cmyk Acceleration levels of dropped objects Introduction his paper is intended to provide an overview of drop shock testing, which is defined as the acceleration

### Rock Mechanics I Course CEE9577. Properties of Rocks

Rock Mechanics I Course CEE9577 Properties of Rocks Rock as an Engineering Material Rock as an Engineering Material It differs from other engineering materials in that it contains discontinuities such

### physics 1/12/2016 Chapter 20 Lecture Chapter 20 Traveling Waves

Chapter 20 Lecture physics FOR SCIENTISTS AND ENGINEERS a strategic approach THIRD EDITION randall d. knight Chapter 20 Traveling Waves Chapter Goal: To learn the basic properties of traveling waves. Slide

### INTERFERENCE OF SOUND WAVES

2011 Interference - 1 INTERFERENCE OF SOUND WAVES The objectives of this experiment are: To measure the wavelength, frequency, and propagation speed of ultrasonic sound waves. To observe interference phenomena

### 1 of 9 2/9/2010 3:38 PM

1 of 9 2/9/2010 3:38 PM Chapter 23 Homework Due: 8:00am on Monday, February 8, 2010 Note: To understand how points are awarded, read your instructor's Grading Policy. [Return to Standard Assignment View]

### PIPELINE INSPECTION UTILIZING ULTRASOUND TECHNOLOGY: ON THE ISSUE OF RESOLUTION By, M. Beller, NDT Systems & Services AG, Stutensee, Germany

ABSTRACT: PIPELINE INSPECTION UTILIZING ULTRASOUND TECHNOLOGY: ON THE ISSUE OF RESOLUTION By, M. Beller, NDT Systems & Services AG, Stutensee, Germany Today, in-line inspection tools are used routinely

### Waves - Transverse and Longitudinal Waves

Waves - Transverse and Longitudinal Waves wave may be defined as a periodic disturbance in a medium that carries energy from one point to another. ll waves require a source and a medium of propagation.

### Dispersion diagrams of a water-loaded cylindrical shell obtained from the structural and acoustic responses of the sensor array along the shell

Dispersion diagrams of a water-loaded cylindrical shell obtained from the structural and acoustic responses of the sensor array along the shell B.K. Jung ; J. Ryue ; C.S. Hong 3 ; W.B. Jeong ; K.K. Shin

### HET408 Medical Imaging. The Physics of Diagnostic Ultrasound

HET408 Medical Imaging The Physics of Diagnostic Ultrasound 1 1 Introduction All conventional diagnostic ultrasound equipment depends on the ability of ultrasound waves to reflect from tissue interfaces.

### Determination of source parameters from seismic spectra

Topic Determination of source parameters from seismic spectra Authors Michael Baumbach, and Peter Bormann (formerly GeoForschungsZentrum Potsdam, Telegrafenberg, D-14473 Potsdam, Germany); E-mail: pb65@gmx.net

### Fric-3. force F k and the equation (4.2) may be used. The sense of F k is opposite

4. FRICTION 4.1 Laws of friction. We know from experience that when two bodies tend to slide on each other a resisting force appears at their surface of contact which opposes their relative motion. The

### Fatigue :Failure under fluctuating / cyclic stress

Fatigue :Failure under fluctuating / cyclic stress Under fluctuating / cyclic stresses, failure can occur at loads considerably lower than tensile or yield strengths of material under a static load: Fatigue

### Waves-Wave Characteristics

1. What is the wavelength of a 256-hertz sound wave in air at STP? 1. 1.17 10 6 m 2. 1.29 m 3. 0.773 m 4. 8.53 10-7 m 2. The graph below represents the relationship between wavelength and frequency of

### Synthetic Sensing: Proximity / Distance Sensors

Synthetic Sensing: Proximity / Distance Sensors MediaRobotics Lab, February 2010 Proximity detection is dependent on the object of interest. One size does not fit all For non-contact distance measurement,

### Energy Transport. Focus on heat transfer. Heat Transfer Mechanisms: Conduction Radiation Convection (mass movement of fluids)

Energy Transport Focus on heat transfer Heat Transfer Mechanisms: Conduction Radiation Convection (mass movement of fluids) Conduction Conduction heat transfer occurs only when there is physical contact

### v = λ f this is the Golden Rule for waves transverse & longitudinal waves Harmonic waves The golden rule for waves Example: wave on a string Review

L 23 Vibrations and Waves [3] resonance clocks pendulum springs harmonic motion mechanical waves sound waves golden rule for waves musical instruments The Doppler effect Doppler radar radar guns Review

### 08/19/09 PHYSICS 223 Exam-2 NAME Please write down your name also on the back side of this exam

08/19/09 PHYSICS 3 Exam- NAME Please write down your name also on the back side of this exam 1. A sinusoidal wave of frequency 500 Hz has a speed of 350 m/s. 1A. How far apart (in units of cm) are two

### The He-Ne Laser * He-Ne Laser System. Power supply and ballast. interatomic collision. 1E-7 sec

The He-Ne Laser * I. Introduction The He-Ne laser (Figure 1) uses a low pressure (ca. 1 Torr He, 0.1 Torr Ne) mixture excited by a dc electric discharge. A ballast resistor is placed in series with the

### Name Date Day/Time of Lab Partner(s) Lab TA

Name Date Day/Time of Lab Partner(s) Lab TA Objectives LAB 7: AC CIRCUITS To understand the behavior of resistors, capacitors, and inductors in AC Circuits To understand the physical basis of frequency-dependent

### Laminar and Turbulent flow. Flow Sensors. Reynolds Number. Thermal flow Sensor. Flow and Flow rate. R = Mass Flow controllers

Flow and Flow rate. Laminar and Turbulent flow Laminar flow: smooth, orderly and regular Mechanical sensors have inertia, which can integrate out small variations due to turbulence Turbulent flow: chaotic

### Earthquake source mechanics

Earthquake source mechanics Lecture 6 Seismic moment Earthquake magnitude Richter magnitude scale M = log A( ) - log A 0 ( ) where A is max trace amplitude at distance and A 0 is at 100 km Surface wave

### The elements used in commercial codes can be classified in two basic categories:

CHAPTER 3 Truss Element 3.1 Introduction The single most important concept in understanding FEA, is the basic understanding of various finite elements that we employ in an analysis. Elements are used for

### Yield Criteria for Ductile Materials and Fracture Mechanics of Brittle Materials. τ xy 2σ y. σ x 3. τ yz 2σ z 3. ) 2 + ( σ 3. σ 3

Yield Criteria for Ductile Materials and Fracture Mechanics of Brittle Materials Brittle materials are materials that display Hookean behavior (linear relationship between stress and strain) and which

Chapter 20. Traveling Waves You may not realize it, but you are surrounded by waves. The waviness of a water wave is readily apparent, from the ripples on a pond to ocean waves large enough to surf. It

### Adam Zaborski handouts for Afghans

Tensile test Adam Zaborski handouts for Afghans Outline Tensile test purpose Universal testing machines and test specimens Stress-strain diagram Mild steel : proportional stage, elastic limit, yielding

### PIEZO CERAMICS. Noliac Group develops and manufactures piezoelectric. zirconate titanate (PZT) of high quality and tailored for custom

Noliac Group develops and manufactures piezoelectric zirconate titanate (PZT) of high quality and tailored for custom Piezoelectric components may be used as e.g.: Actuators Sensors Generators Transducers

### Piezo Technologies - Technical Resource Paper

An Overview of the Properties of Different Piezoceramic Materials Material Families Four of the more important types of piezoceramic materials are introduced below. Lead Zirconate-Titanate - Because of

### Study Guide and Review for Electricity and Light Lab Final

Study Guide and Review for Electricity and Light Lab Final This study guide is provided to help you prepare for the lab final. The lab final consists of multiplechoice questions, usually two for each unit,

### Positive Feedback and Oscillators

Physics 3330 Experiment #6 Fall 1999 Positive Feedback and Oscillators Purpose In this experiment we will study how spontaneous oscillations may be caused by positive feedback. You will construct an active

### Chapter 5: Tool Dynamometers

Chapter 5: Tool Dynamometers LEARNING OBJECTIVES Different types of transducers used in Dynamometers Design Requirements Types of Dynamometers ---------------------------------------------------------------------------------------------------------------------

### 4 SENSORS. Example. A force of 1 N is exerted on a PZT5A disc of diameter 10 mm and thickness 1 mm. The resulting mechanical stress is:

4 SENSORS The modern technical world demands the availability of sensors to measure and convert a variety of physical quantities into electrical signals. These signals can then be fed into data processing

### Ultrasound Distance Measurement

Final Project Report E3390 Electronic Circuits Design Lab Ultrasound Distance Measurement Yiting Feng Izel Niyage Asif Quyyum Submitted in partial fulfillment of the requirements for the Bachelor of Science

### Objectives. Experimentally determine the yield strength, tensile strength, and modules of elasticity and ductility of given materials.

Lab 3 Tension Test Objectives Concepts Background Experimental Procedure Report Requirements Discussion Objectives Experimentally determine the yield strength, tensile strength, and modules of elasticity

### EDEXCEL NATIONAL CERTIFICATE/DIPLOMA MECHANICAL PRINCIPLES AND APPLICATIONS NQF LEVEL 3 OUTCOME 1 - LOADING SYSTEMS

EDEXCEL NATIONAL CERTIFICATE/DIPLOMA MECHANICAL PRINCIPLES AND APPLICATIONS NQF LEVEL 3 OUTCOME 1 - LOADING SYSTEMS TUTORIAL 1 NON-CONCURRENT COPLANAR FORCE SYSTEMS 1. Be able to determine the effects

### Doppler. Doppler. Doppler shift. Doppler Frequency. Doppler shift. Doppler shift. Chapter 19

Doppler Doppler Chapter 19 A moving train with a trumpet player holding the same tone for a very long time travels from your left to your right. The tone changes relative the motion of you (receiver) and

### 1. Fluids Mechanics and Fluid Properties. 1.1 Objectives of this section. 1.2 Fluids

1. Fluids Mechanics and Fluid Properties What is fluid mechanics? As its name suggests it is the branch of applied mechanics concerned with the statics and dynamics of fluids - both liquids and gases.

### TIE-31: Mechanical and thermal properties of optical glass

PAGE 1/10 1 Density The density of optical glass varies from 239 for N-BK10 to 603 for SF66 In most cases glasses with higher densities also have higher refractive indices (eg SF type glasses) The density

### PUMPED Nd:YAG LASER. Last Revision: August 21, 2007

PUMPED Nd:YAG LASER Last Revision: August 21, 2007 QUESTION TO BE INVESTIGATED: How can an efficient atomic transition laser be constructed and characterized? INTRODUCTION: This lab exercise will allow

### LOW COST MOTOR PROTECTION FILTERS FOR PWM DRIVE APPLICATIONS STOPS MOTOR DAMAGE

LOW COST MOTOR PROTECTION FILTERS FOR PWM DRIVE APPLICATIONS STOPS MOTOR DAMAGE Karl M. Hink, Executive Vice President Originally presented at the Power Quality 99 Conference ABSTRACT Motor protection

### 1. Oscilloscope is basically a graph-displaying device-it draws a graph of an electrical signal.

CHAPTER 3: OSCILLOSCOPE AND SIGNAL GENERATOR 3.1 Introduction to oscilloscope 1. Oscilloscope is basically a graph-displaying device-it draws a graph of an electrical signal. 2. The graph show signal change

### v = fλ PROGRESSIVE WAVES 1 Candidates should be able to :

PROGRESSIVE WAVES 1 Candidates should be able to : Describe and distinguish between progressive longitudinal and transverse waves. With the exception of electromagnetic waves, which do not need a material

### Spectrum Level and Band Level

Spectrum Level and Band Level ntensity, ntensity Level, and ntensity Spectrum Level As a review, earlier we talked about the intensity of a sound wave. We related the intensity of a sound wave to the acoustic

### ELECTRON SPIN RESONANCE Last Revised: July 2007

QUESTION TO BE INVESTIGATED ELECTRON SPIN RESONANCE Last Revised: July 2007 How can we measure the Landé g factor for the free electron in DPPH as predicted by quantum mechanics? INTRODUCTION Electron

### Principles of Medical Ultrasound. Pai-Chi Li Department of Electrical Engineering National Taiwan University

Principles of Medical Ultrasound Pai-Chi Li Department of Electrical Engineering National Taiwan University What is Medical Ultrasound? Prevention: actions taken to avoid diseases. Diagnosis: the process

### PHYS 2426 Engineering Physics II (Revised July 7, 2011) AC CIRCUITS: RLC SERIES CIRCUIT

PHYS 2426 Engineering Physics II (Revised July 7, 2011) AC CIRCUITS: RLC SERIES CIRCUIT INTRODUCTION The objective of this experiment is to study the behavior of an RLC series circuit subject to an AC

### Experiment 5. Lasers and laser mode structure

Northeastern University, PHYS5318 Spring 2014, 1 1. Introduction Experiment 5. Lasers and laser mode structure The laser is a very important optical tool that has found widespread use in science and industry,

### Module 13 : Measurements on Fiber Optic Systems

Module 13 : Measurements on Fiber Optic Systems Lecture : Measurements on Fiber Optic Systems Objectives In this lecture you will learn the following Measurements on Fiber Optic Systems Attenuation (Loss)

### Acousto-Optic Modulation

AN0510 Acousto-Optic Modulation Acousto-optic devices are primarily used for controlling laser beams. This includes Modulators, Deflectors, Tuneable Filters, Frequency Shifters and Q-switches. The basic

### Lab 9: The Acousto-Optic Effect

Lab 9: The Acousto-Optic Effect Incoming Laser Beam Travelling Acoustic Wave (longitudinal wave) O A 1st order diffracted laser beam A 1 Introduction qb d O 2qb rarefractions compressions Refer to Appendix

### Lab #9: AC Steady State Analysis

Theory & Introduction Lab #9: AC Steady State Analysis Goals for Lab #9 The main goal for lab 9 is to make the students familar with AC steady state analysis, db scale and the NI ELVIS frequency analyzer.

### Antenna Properties and their impact on Wireless System Performance. Dr. Steven R. Best. Cushcraft Corporation 48 Perimeter Road Manchester, NH 03013

Antenna Properties and their impact on Wireless System Performance Dr. Steven R. Best Cushcraft Corporation 48 Perimeter Road Manchester, NH 03013 Phone (603) 627-7877 FAX: (603) 627-1764 Email: sbest@cushcraft.com

### Acoustics: the study of sound waves

Acoustics: the study of sound waves Sound is the phenomenon we experience when our ears are excited by vibrations in the gas that surrounds us. As an object vibrates, it sets the surrounding air in motion,

### Stress and Deformation Analysis. Representing Stresses on a Stress Element. Representing Stresses on a Stress Element con t

Stress and Deformation Analysis Material in this lecture was taken from chapter 3 of Representing Stresses on a Stress Element One main goals of stress analysis is to determine the point within a load-carrying