FRICTION INDUCED IRREVERSIBLE STRETCHING OF SUBSTRATE FILMS BY RECOR- DING WITH A CATAMARAN GLIDER ON THIN FILM FLOPPY DISKS
|
|
- Buddy Freeman
- 1 years ago
- Views:
Transcription
1 Journal of the Magnetics Society of Japan Vol. 15 Supplement, No. S2 (1991) 1991 by The Magnetics Society of Japan FRICTION INDUCED IRREVERSIBLE STRETCHING OF SUBSTRATE FILMS BY RECOR- DING WITH A CATAMARAN GLIDER ON THIN FILM FLOPPY DISKS Hans-Peter SCHILDBERG and Hartmut HIBST BASF Aktiengesellschaft, Ammoniaklaboratorium, D-6700 Ludwigshafen, Germany The tribological interaction between a commercial floppy disk catamaran glider and flexible magnetic thin film media is investigated on a tribometer under floppy disk drive conditions. Apart from the usual wear scars which develop in the metallic thin film due to abrasion and microploughing, one observes elevations of the medium (up to 15 Ilm) along the track of the head. The profile of these elevations in directions perpendicular to the track reflects the two rails of the catamaran glider and strongly depends on the thickness of the polymer substrate, its elastic properties and on the frictional force between head and medium. The observations are explained by the distribution of shear forces in that region of the polymer substrate which is directly underneath and besides the rails of the sliding R/W-head. Consequences for magnetic recording, the selection of substrate films and the head/tape interface are considered. INTRODUCTION Magnetic thin film media on flexible substrates allow for substantially higher storage densities than particulate media. However, severe tribological problems are encountered with the employment of these media in recording devices of the helical scan or floppy drive type. For recording with the former type one has recently managed to successfully employ a Co-Ni-O thin film tape (Video Hi8). For the latter type, where the tribological requirements are much stricter, one has not yet succeeded in introducing a commercial thin film floppy. In this paper we report about a new, detrimental tribological phenomenon which manifests itself by irreversible deformations of the substrate film along the track of a floppy head due to the frictional forces between head and medium. EXPERIMENTAL A conventional tribometer is used to investigate the interaction between head and thin film medium (R/W-head: commercial Mitsubishi catamaran glider from 5.25" floppy drive, 135 tpi; head load: 0.1 N; spinning speed: 300 rpm). The media (Cr/Co-Ni-Cr or Co-cr deposited on PI or PET, thickness: 9 to 50 Ilm) were lubricated with Fomblin-AM2001 by dip coating. After head passes the polymer substrate film exhibits distinct deformations parallel to the track (fig.1).the highest elevations are observed close to the edges of the two rails of the catamaran glider (fig. 2). For thinner films the bumps come out more clearly resolved. It is remarkable that these elevations encompass the entire foil (fig. 3). The distinct drop of the friction coefficient in the interval of loo to 300 revolutions (fig. 4) indicates that the deformations develop during the first 300 revolutions. Thereafter the contact area between the rails of the head and the lubricated medium is substantially reduced and a much lower friction coefficient is obtained. At this stage any attempt to record onto the medium or to retrieve old information is absolutely hopeless, because the distance between the pole tips of the R/W-head and the surface of the thin film medium is of the order of several micrometers. INTERPRETATION Due to non-zero friction between head and medium the part of the medium directly under the rails of the catamaran glider is dragged in direction of head movement until the shear forces that develop immediately in the film attain a value capable to counterbalance the frictional force acting on the film beneath the rails (fig. 5). For a detailed explanation we resort to a onedimensional model (fig. 6). We imagine the medium as being of infinite length in x-direction and of large width in y-direction. Furthermore, to model the elastic properties of the medium (which constitutes a continuum in the theory of elasticity), we regard it as being composed of rigid stripes of infinitesimal width, oriented in x-direction. Between two adjacent stripes we imagine springs that allow for a relative displacement in x-direction (shear). The outermost stripes in y-direction are regarded as being fixed in space (i.e. cannot be displaced in x-direction). A rail of finite width in y-direction and infinite length in x- direction is placed onto the medium. With the rail being still at rest we draw a line across the medium to mark the original x-position of all stripes. After the head has started sliding at constant speed in x-direction, the x-position of the stripes will change as indicated by the position of the
2 a) a) l E ::1.: bt.:1 ;: so '" j25. OlD SOU.O (10 2$ relative distance ill..,adial direction [Illll] C 2.o ,-,-, ,...,...,-., ,.-,-,--..--,--.-,,...,!4.0.l!.;;03.0 -; 2.0.t;.g 1.0 o.o,f;:/7--'--'-";;ioo<l;;;;.oi500;;;;.o--':"-";/ ""'.o/':":"':"";;;2500i;:o.o--';3000;;;i;:o'-.o 0.0 relative distance in radial direction {pm}, Fig. 2: Scans with a stylus profilometer over the surface of the media shown in fig. 1. The horizontal scale of the schematic cross section of the catamaran glider (a) is identical to the horizontal scale used for the profiles (b) and (c). c) 65.0 metallized side of PI-foil (top side) 'i' : Polyimide bulk material, 50 m thick 15.0 R129mm Fig. 1: Optical micrograph of the surface of thin film samples after head passes performed with a catamaran glider at different radii R. Apart from the usual small wear scars one observes distinct elevations in the medium. (a): catamaran glider. (b): PI(Upilex R, 50 Ilm)/C<ry8Cr22(192nm) (c): PET(36VXR502, 9Ilm)/Cr(200nm)/ C062.5Ni30Cr7.5(50nm) rear side of PI-foil toe/ative distance in radial direction [um] Fig. 3: Cross section of the medium shown in fig. l(b) as determined by two scans with a stylus profilometer on the top and rear side of the medium
3 number DJ Tel'oJution Fig. 4: Friction coefficient recorded for the sample shown in fig. l(b) as function of revolutions. Note the unusual scale of the horizontal axis. under the rail. The shear forces between stripes 2 and 3 and between stripes -2 and -3, i.e. F s,2 and F s,-2, are of course smaller because they only need to counteract the forces Ff exerted on the stripes enclosed between stripes 3 and -3. Exactly under the centre the shear forces are zero, because stripe 1 and - 1 exhibit no displacement relative to each other. Thus the shear forces in the substrate film linearly increase from a point under the centre of the rail to its edges. The slope of this linear function is independent of the width of the rail but only depends (linearly!) on the friction coefficient. Consequently, the broader the rail, the larger the shear forces in the film under the edges. Outside the rail, i.e. starting with stripe 4 and - 4, the shear forces stay constant in the purely one dimensional model. However, in reality the rail of the head is only of fmite length. This is why in real systems the shear forces decay to zero with increasing distance from the track. Their maximum value is thus attained under the edges of the rail. Any shear force causes the medium to be stretched. Upon relaxation after the head has passed by, the polymer substrate film never fully contracts to its original shape but exhibits some irreversible Fig. 5: Due to friction between the rail of the R/Whead and the surface of the thin film the medium is dragged in direction of the sliding rail (curved arrows). line segments on each stripe (fig. 6). This displacement is due to non-zero friction between rail and medium which causes the surface of each stripe under the sliding rail experiencing the same force per unit length F f dragging the stripe in x-direction. Of course, the surfaces of all9ther stripes not covered by the rail do not experience this force. The forces Ff will be counterbalanced by shear forces F s that act between adjacent stripes. (Here we define shear force as integral of the shear stress over the thickness of the substrate film. The resulting unit is hence force per unit length). The shear forces between the first stripes outside the rail (nos. 4 and -4) and the outermost stripe under the rail (nos. 3 and -3), i.e. F s,3 and F s,_ 3, have to counteract all forces Ff acting on the stripes F s, -s s; F s, -4 'd F s, -4 S; F s, -3 F s,-3 = 3 F f.. F s,-2 = 2 F f Fs,_1 =lf f F s,o =0 F s,l = 1 F f Fs,2 =2F f F s,3 =3F.. F s,4 S;F s, 3 F s,5 S;F s,4 J.. x direction of head movement relative to the tape Fig. 6: One dimensional model to explain the elevations in the substrate film due to shear stress induced by friction between head and medium
4 component of stretching. In a cyclic process as in a floppy drive (which corresponds to our tribometer) these components accumulate. Because the shear forces attain their highest values at the edges of the rails, the irreversible components of streching will also be largest in these region. Since the medium far away from the circular track remains unchanged in its lateral dimensions, the substrate film bends upwards along the track to accommodate the lateral increment. This upward direction is due to the fact that the shear stress is not constant over the thickness of the substrate film, but actually decreases with distance from the surface and thus a correspondingly less lateral increment deep in the fllm is brought about. (The absolute difference between the shear stress close to the surface and close to the rear side of the film will be rather small, because the thickness of the common substrate fllms (9 to 75 f.1m) is very small compared to the width of the rail). Bending upwards takes advantage of this variation over the thickness of the film, because the curvature in the highest point of the peaks requires the largest lateral stretching at the surface and less lateral stretching or even compression at the rear side. CONCLUSION Since the friction induced irreversible deformations of the substrate fllms are caused by irreversible stretching, the following measures would alleviate this problem: a) use of substrate fllms with higher E-moduli b) use of thicker substrate fllms c) use of heads with narrower rails d) realization of lower friction coefficients a) The stiffer the substrate film, the smaller are in general the irreversible components when being stretched. Fig. 7 shows two samples that were prepared and investigated under identical conditions. The sample with twice the large E-modulus exhibits elevations only about half as high. b) The magnitude of the shear stress between two adjacent stripes in our one dimensional model is of course inversely proportional to the thickness of the substrate fllm, because the integral of the shear stress over the thickness must be equal to a force per unit length solely determined by the friction coefficient and the position in y-direction (fig.6). This means that media based on thicker substrate films (all other parameters assumed equal, which entails in particular identical friction coefficients) are less prone to the irreversible deformations discussed in this paper. Alternatively one could say that if we intend to produce a thin fllm medium with the substrate film 20.0 r--r-.,.-,--,..-..,.--r-,...,-.,.-.-,..--r-.., ;-"'-'--"'-",,--, i",..",,,,,,,,,i '.,J :: ] 1: 5.0 PI (Upilex R), 501lm, E modulus: 3400N/mm L...=::::..-'-..l..-.J.-'---'--.J...L-'--'--.J.-...L--"-:::::.=-... loooo.o relative distance in radial direction [urn] PI (Upilex S), 50llm, ' 15.0 E-modulus:..:::. 6200N/mm2?o ] ',::: 5.0 '" : III III 1Ii, :. Ill" \,\ \I O..LO -===:i::...j'-25..l.00-.d.j.-'---'--.j.5-dd.ld-.d'--'---'---'::75::00.0:"-=1-:-: relative distance in radial direction [urn] Fig. 7: Comparision of the change of the surface proflle of two thin film media [PI(50f.1m)/Cr(200nm)1 C062.5Ni30Cr7. 5 (50nm) ] after revolutions with a catamaran glider. The media differ only by the E-moduli of their substrate fllms. The magnetic coating, the lubricant (Fomblin AM2001) and the experimental conditions are identical. thickness being reduced by a factor of 2, say, we should take care to get the friction coefficient down by the same amount in order to keep the shear stress at the same level as for the thicker medium. c) Since the maximum shear force occurring depends linearly on the width of the rail, the need for employing heads with rails as narrow as possible is obvious. " d): Since the slope of the function describing the linear increase of the shear forces in the substrate fllm depends linearly on the friction coefficient, lubricants and surface topography of the media (e.g. nodules as for ME-tape) have to be optimized for yielding friction coefficients as low as possible. The simplest way to reduce friction, namely by increasing the Ra-value of the medium, is not operational for thin film media, because it entails increasing distance loss and thus jeopardizes the goal of higher storage densities we just attempted to achieve by switching from particulate to thin film coatings
5 The reasons for commercial particulate floppy disks not exhibiting the elevations described in this paper ly in the thickness of their substrate film (75 instead of 50 m) and in their low friction coefficient of about For the sample of fig. 1 b the initial friction coefficient was close to 1.0, probably due to the extreme smoothness of the substrate film (Ra = 3 nm). SUMMARY The circular elevations observed in thin film floppy disks when recording with a catamaran glider are due to friction induced shear forces in the substrate film. These forces increase linearly from a point under the centre of the rail to its edges. The slope defining this increase only depends on the friction coefficient in a linear manner. The maximum shear forces and hence maximum components of the induced irreversible stretching in the substrate film occur under the edges of the rails. The increment in the lateral dimensions of the substrate film along the track of the head is accommodated by forming elevations. These deformations are fatal to recording or retrieving data. They can be reduced by using substrate films with higher E-moduli, by increasing the thickness of the substrate films, by realizing lower friction coefficients and by using heads with narrower rails
CENG 501 Examination Problem: Estimation of Viscosity with a Falling - Cylinder Viscometer
CENG 501 Examination Problem: Estimation of Viscosity with a Falling - Cylinder Viscometer You are assigned to design a fallingcylinder viscometer to measure the viscosity of Newtonian liquids. A schematic
Sinan Müftü Associate Professor Department of Mechanical Engineering Northeastern University, 334 SN Boston, MA
TAPE MECHANICS OVER A FLAT RECORDING HEAD UNDER UNIFORM PULL-DOWN PRESSURE Sinan Müftü Associate Professor Department of Mechanical Engineering Northeastern University, 334 SN Boston, MA 115-5 Submitted
Physics. Assignment-1(UNITS AND MEASUREMENT)
Assignment-1(UNITS AND MEASUREMENT) 1. Define physical quantity and write steps for measurement. 2. What are fundamental units and derived units? 3. List the seven basic and two supplementary physical
Testing and Analysis
Testing and Analysis Testing Elastomers for Hyperelastic Material Models in Finite Element Analysis 2.6 2.4 2.2 2.0 1.8 1.6 1.4 Biaxial Extension Simple Tension Figure 1, A Typical Final Data Set for Input
Chapter 3 LAMINATED MODEL DERIVATION
17 Chapter 3 LAMINATED MODEL DERIVATION 3.1 Fundamental Poisson Equation The simplest version of the frictionless laminated model was originally introduced in 1961 by Salamon, and more recently explored
THE WORK OF A FORCE, THE PRINCIPLE OF WORK AND ENERGY & SYSTEMS OF PARTICLES
THE WORK OF A FORCE, THE PRINCIPLE OF WORK AND ENERGY & SYSTEMS OF PARTICLES Today s Objectives: Students will be able to: 1. Calculate the work of a force. 2. Apply the principle of work and energy to
197 1st Avenue, Suite 120, Needham MA Tel Fax
197 1st Avenue, Suite 120, Needham MA 02494 Tel 781-444-2250 Fax 781-444-2251 USinfo@csm-instruments.com www.csm-instruments.com //// T 09 113 Wear and Friction Analysis of Thin Coatings An in-depth study
Figure 43. Some common mechanical systems involving contact.
33 Demonstration: experimental surface measurement ADE PhaseShift Whitelight Interferometer Surface measurement Surface characterization - Probability density function - Statistical analyses - Autocorrelation
Practice. Newton s 3 Laws of Motion. Recall. Forces a push or pull acting on an object; a vector quantity measured in Newtons (kg m/s²)
Practice A car starts from rest and travels upwards along a straight road inclined at an angle of 5 from the horizontal. The length of the road is 450 m and the mass of the car is 800 kg. The speed of
Special edition paper
Development of New Aseismatic Structure Using Escalators Kazunori Sasaki* Atsushi Hayashi* Hajime Yoshida** Toru Masuda* Aseismatic reinforcement work is often carried out in parallel with improvement
ECC Media Technology. 1. Introduction. 2. ECC Media. Shunji Takenoiri TuQiang Li Yoshiyuki Kuboki
ECC Media Technology Shunji Takenoiri TuQiang Li Yoshiyuki Kuboki 1. Introduction Two years have already elapsed since Fuji Electric began mass-producing perpendicular magnetic recording media, and now
Peak Strain and Displacement Sensors for Structural Health Monitoring
Peak Strain and Displacement Sensors for Structural Health Monitoring AKIRA MITA and SHINPEI TAKAHIRA ABSTRACT Simple and inexpensive passive sensors that can monitor the peak strain or displacement of
Answers: Internal Processes and Structures (Isostasy)
Answers: Internal Processes and Structures (Isostasy) 1. Analyse the adjustment of the crust to changes in loads associated with volcanism, mountain building, erosion, and glaciation by using the concept
SEISMIC BASE ISOLATION
SEISMIC BASE ISOLATION DESIGN OF BASE ISOLATION SYSTEMS IN BUILDINGS FILIPE RIBEIRO DE FIGUEIREDO SUMMARY The current paper aims to present the results of a study for the comparison of different base isolation
ROCK TRIBOLOGY USING TRIBOMETER
ROCK TRIBOLOGY USING TRIBOMETER Prepared by Duanjie Li, PhD 6 Morgan, Ste156, Irvine CA 92618 P: 949.461.9292 F: 949.461.9232 nanovea.com Today's standard for tomorrow's materials. 2015 NANOVEA INTRO Rocks
Stress-Strain Behavior
Stress-Strain Behavior 6.3 A specimen of aluminum having a rectangular cross section 10 mm 1.7 mm (0.4 in. 0.5 in.) is pulled in tension with 35,500 N (8000 lb f ) force, producing only elastic deformation.
4 Deforming the Earth s Crust
CHAPTER 7 4 Deforming the Earth s Crust SECTION Plate Tectonics BEFORE YOU READ After you read this section, you should be able to answer these questions: What happens when rock is placed under stress?
7.4 The Elementary Beam Theory
7.4 The Elementary Beam Theory In this section, problems involving long and slender beams are addressed. s with pressure vessels, the geometry of the beam, and the specific type of loading which will be
MECHANICAL PROPERTIES OF SOLIDS
Chapter Nine MECHANICAL PROPERTIES OF SOLIDS MCQ I 9.1 Modulus of rigidity of ideal liquids is (a) infinity. (b) zero. (c) unity. (d) some finite small non-zero constant value. 9. The maximum load a wire
Module 7 Design of Springs. Version 2 ME, IIT Kharagpur
Module 7 Design of Springs Lesson 1 Introduction to Design of Helical Springs Instructional Objectives: At the end of this lesson, the students should be able to understand: Uses of springs Nomenclature
Transactions on Engineering Sciences vol 14, 1997 WIT Press, ISSN
On the Computation of Elastic Elastic Rolling Contact using Adaptive Finite Element Techniques B. Zastrau^, U. Nackenhorst*,J. Jarewski^ ^Institute of Mechanics and Informatics, Technical University Dresden,
Atomic Force Microscopy imaging and beyond
Atomic Force Microscopy imaging and beyond Arif Mumtaz Magnetism and Magnetic Materials Group Department of Physics, QAU Coworkers: Prof. Dr. S.K.Hasanain M. Tariq Khan Alam Imaging and beyond Scanning
Study Questions/Problems Week 4
Study Questions/Problems Week 4 Chapter 6 treats many topics. I have selected on average less than three problems from each topic. I suggest you do them all. Likewise for the Conceptual Questions and exercises,
2014 MECHANICS OF MATERIALS
R10 SET - 1 II. Tech I Semester Regular Examinations, March 2014 MEHNIS OF MTERILS (ivil Engineering) Time: 3 hours Max. Marks: 75 nswer any FIVE Questions ll Questions carry Equal Marks ~~~~~~~~~~~~~~~~~~~~~~~~~
Basic Laboratory. Materials Science and Engineering. Atomic Force Microscopy (AFM)
Basic Laboratory Materials Science and Engineering Atomic Force Microscopy (AFM) M108 Stand: 20.10.2015 Aim: Presentation of an application of the AFM for studying surface morphology. Inhalt 1.Introduction...
D Y N A M I C M E C H A N I C A L A N A L Y S I S A N D I T S A D V A N T A G E S O V E R D E F L E C T I O N T E M P E R A T U R E U N D E R L O A D
D Y N A M I C M E C H A N I C A L A N A L Y S I S A N D I T S A D V A N T A G E S O V E R D E F L E C T I O N T E M P E R A T U R E U N D E R L O A D Sujan E. Bin Wadud TA Instruments 9 Lukens Drive, New
Chapter 7 Potential Energy and Energy Conservation
Chapter 7 Potential Energy and Energy Conservation We saw in the previous chapter the relationship between work and kinetic energy. We also saw that the relationship was the same whether the net external
Module 26: Atomic Force Microscopy. Lecture 40: Atomic Force Microscopy 3: Additional Modes of AFM
Module 26: Atomic Force Microscopy Lecture 40: Atomic Force Microscopy 3: Additional Modes of AFM 1 The AFM apart from generating the information about the topography of the sample features can be used
Announcements. Principle of Work and Energy - Sections Engr222 Spring 2004 Chapter Test Wednesday
Announcements Test Wednesday Closed book 3 page sheet sheet (on web) Calculator Chap 12.6-10, 13.1-6 Principle of Work and Energy - Sections 14.1-3 Today s Objectives: Students will be able to: a) Calculate
A General Equation for Fitting Contact Area and Friction vs Load Measurements
Journal of Colloid and Interface Science 211, 395 400 (1999) Article ID jcis.1998.6027, available online at http://www.idealibrary.com on A General Equation for Fitting Contact Area and Friction vs Load
Objectives: After completion of this module, you should be able to:
Chapter 12 Objectives: After completion of this module, you should be able to: Demonstrate your understanding of elasticity, elastic limit, stress, strain, and ultimate strength. Write and apply formulas
EE C247B / ME C218 INTRODUCTION TO MEMS DESIGN SPRING 2016 C. NGUYEN PROBLEM SET #4
Issued: Wednesday, March 4, 2016 PROBLEM SET #4 Due: Monday, March 14, 2016, 8:00 a.m. in the EE C247B homework box near 125 Cory. 1. This problem considers bending of a simple cantilever and several methods
MOTION OF A CHARGED PARTICLE IN A UNIFORM MAGNETIC FIELD
MOTION OF A CHARGED PARTICLE IN A UNIFORM MAGNETIC FIELD When the velocity of a charged particle is perpendicular to a uniform magnetic field, the particle moves in a circular path in a plane perpendicular
UNIVERSITY PHYSICS I. Professor Meade Brooks, Collin College. Chapter 12: STATIC EQUILIBRIUM AND ELASTICITY
UNIVERSITY PHYSICS I Professor Meade Brooks, Collin College Chapter 12: STATIC EQUILIBRIUM AND ELASTICITY Two stilt walkers in standing position. All forces acting on each stilt walker balance out; neither
Design of a fastener based on negative Poisson's ratio foam adapted from
1 Design of a fastener based on negative Poisson's ratio foam adapted from Choi, J. B. and Lakes, R. S., "Design of a fastener based on negative Poisson's ratio foam", Cellular Polymers, 10, 205-212 (1991).
Coating Requirements for Pipelines Installed by Horizontal Directional Drilling John D. Hair, P.E.*
Coating Requirements for Pipelines Installed by Horizontal Directional Drilling John D. Hair, P.E.* *President, J. D. Hair & Associates, Inc., 2121 South Columbia Avenue, Suite 101, Tulsa, OK 74114-3502;
DETERMINING THE STRESS PATTERN IN THE HH RAILROAD TIES DUE TO DYNAMIC LOADS 1
PERIODICA POLYTECHNICA SER. CIV. ENG. VOL. 46, NO. 1, PP. 125 148 (2002) DETERMINING THE STRESS PATTERN IN THE HH RAILROAD TIES DUE TO DYNAMIC LOADS 1 Nándor LIEGNER Department of Highway and Railway Engineering
ME 230 Kinematics and Dynamics
ME 230 Kinematics and Dynamics Wei-Chih Wang Department of Mechanical Engineering University of Washington Lecture 8 Kinetics of a particle: Work and Energy (Chapter 14) - 14.1-14.3 W. Wang 2 Kinetics
MARKS DISTRIBUTION AS PER CHAPTER (QUESTION ASKED IN GTU EXAM) Name Of Chapter. Applications of. Friction. Centroid & Moment.
Introduction Fundamentals of statics Applications of fundamentals of statics Friction Centroid & Moment of inertia Simple Stresses & Strain Stresses in Beam Torsion Principle Stresses DEPARTMENT OF CIVIL
Forces. Unit 2. Why are forces important? In this Unit, you will learn: Key words. Previously PHYSICS 219
Previously Remember From Page 218 Forces are pushes and pulls that can move or squash objects. An object s speed is the distance it travels every second; if its speed increases, it is accelerating. Unit
BE Semester- I ( ) Question Bank (MECHANICS OF SOLIDS)
BE Semester- I ( ) Question Bank (MECHANICS OF SOLIDS) All questions carry equal marks(10 marks) Q.1 (a) Write the SI units of following quantities and also mention whether it is scalar or vector: (i)
Please allow us to demonstrate our capabilities and test us testing your samples!
We determine properties of surfaces, thin films, and layer structures Hardness Young s modulus Scratch, friction, and wear tests Topography Mapping of thermal, magnetic, and electronic properties Please
DYNAMIC MECHANICAL ANALYZER DMA 2980
Prepared by Russell R. Ulbrich Sujan E. Bin Wadud DYNAMIC MECHANICAL ANALYZER DMA 2980 Getting Started Guide for Thermal Advantage Users TABLE OF CONTENTS Mearurement Principles of the DMA 2980 1 Force
Chapter 14 Potential Energy and Conservation of Energy
Chapter 4 Potential Energy and Conservation of Energy Chapter 4 Potential Energy and Conservation of Energy... 2 4. Conservation of Energy... 2 4.2 Conservative and Non-Conservative Forces... 3 4.3 Changes
l1, l2, l3, ln l1 + l2 + l3 + ln
Work done by a constant force: Consider an object undergoes a displacement S along a straight line while acted on a force F that makes an angle θ with S as shown The work done W by the agent is the product
SECOND ENGINEER REG. III/2 APPLIED MECHANICS
SECOND ENGINEER REG. III/2 APPLIED MECHANICS LIST OF TOPICS Static s Friction Kinematics Dynamics Machines Strength of Materials Hydrostatics Hydrodynamics A STATICS 1 Solves problems involving forces
Chapter 12. Static Equilibrium and Elasticity
Chapter 12 Static Equilibrium and Elasticity Static Equilibrium Equilibrium implies that the object moves with both constant velocity and constant angular velocity relative to an observer in an inertial
Shear of Thin Walled Beams. Introduction
Introduction Apart from bending, shear is another potential structural failure mode of beams in aircraft For thin-walled beams subjected to shear, beam theory is based on assumptions applicable only to
Physics 218: FINAL EXAM April 29 th, 2016
Physics 218: FINAL EXAM April 29 th, 2016 Please read the instructions below, Do not open the exam until told to do so. Rules of the Exam: 1. You have 120 minutes to complete the exam. 2. Formulae are
Enrico Gnecco Department of Physics. University of Basel, Switzerland
AOSCIECES AD AOTECHOOGIES anotribology - Enrico Gnecco AOTRIBOOGY Enrico Gnecco Department of Physics. University of Basel, Switzerland Keywords: Atomic stick-slip, Friction force microscopy, oad dependence
UNIT 1 STRESS STRAIN AND DEFORMATION OF SOLIDS, STATES OF STRESS 1. Define stress. When an external force acts on a body, it undergoes deformation.
UNIT 1 STRESS STRAIN AND DEFORMATION OF SOLIDS, STATES OF STRESS 1. Define stress. When an external force acts on a body, it undergoes deformation. At the same time the body resists deformation. The magnitude
Section 19.1: Forces Within Earth Section 19.2: Seismic Waves and Earth s Interior Section 19.3: Measuring and Locating.
CH Earthquakes Section 19.1: Forces Within Earth Section 19.2: Seismic Waves and Earth s Interior Section 19.3: Measuring and Locating Earthquakes Section 19.4: Earthquakes and Society Section 19.1 Forces
Adaptive Response of Actin Bundles under Mechanical Stress
Biophysical Journal, Volume 113 Supplemental Information Adaptive Response of Actin Bundles under Mechanical Stress Florian Rückerl, Martin Lenz, Timo Betz, John Manzi, Jean-Louis Martiel, Mahassine Safouane,
MECHANICS OF MATERIALS. Prepared by Engr. John Paul Timola
MECHANICS OF MATERIALS Prepared by Engr. John Paul Timola Mechanics of materials branch of mechanics that studies the internal effects of stress and strain in a solid body. stress is associated with the
Centripetal force keeps an Rotation and Revolution
Centripetal force keeps an object in circular motion. Which moves faster on a merry-go-round, a horse near the outside rail or one near the inside rail? While a hamster rotates its cage about an axis,
Stresses and Strains in flexible Pavements
Stresses and Strains in flexible Pavements Multi Layered Elastic System Assumptions in Multi Layered Elastic Systems The material properties of each layer are homogeneous property at point A i is the same
Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
56 Module 4: Lecture 7 on Stress-strain relationship and Shear strength of soils Contents Stress state, Mohr s circle analysis and Pole, Principal stressspace, Stress pathsin p-q space; Mohr-Coulomb failure
Uniform Circular Motion
Slide 1 / 112 Uniform Circular Motion 2009 by Goodman & Zavorotniy Slide 2 / 112 Topics of Uniform Circular Motion (UCM) Kinematics of UCM Click on the topic to go to that section Period, Frequency, and
Hyperbolic Soil Bearing Capacity
1 Introduction Hyperbolic Soil Bearing Capacity This example involves analyzing the bearing capacity of a round footing. The example is useful for illustrating several SIGMA/W features and procedures,
MAGNETIC EFFECT OF CURRENT
MAGNETIC EFFECT OF CURRENT VERY SHORT ANSWER QUESTIONS Q.1 Who designed cyclotron? Q.2 What is the magnetic field at a point on the axis of the current element? Q.3 Can the path of integration around which
Physics *P43118A0128* Pearson Edexcel GCE P43118A. Advanced Subsidiary Unit 1: Physics on the Go. Tuesday 20 May 2014 Morning Time: 1 hour 30 minutes
Write your name here Surname Other names Pearson Edexcel GCE Physics Advanced Subsidiary Unit 1: Physics on the Go Centre Number Candidate Number Tuesday 20 May 2014 Morning Time: 1 hour 30 minutes You
The Mechanics of CMP and Post-CMP Cleaning
The Mechanics of CMP and Post-CMP Cleaning Sinan Müftü Ahmed Busnaina George Adams Department of Mechanical, Industrial and Manuf. Engineering Northeastern University Boston, MA 02115 Introduction Objective
FLAC3D analysis on soil moving through piles
University of Wollongong Research Online Faculty of Engineering - Papers (Archive) Faculty of Engineering and Information Sciences 211 FLAC3D analysis on soil moving through piles E H. Ghee Griffith University
Universe Video. Magnetic Materials and Magnetic Fields Lab Activity. Discussion of Magnetism and Magnetic Fields
Date Zero Hour In Class Homework Magnetism Intro: Mechanical 1/5 Tue (A) Universe Video 1/6 Wed (B) 1/7 Thur (C) Magnetic Materials and Magnetic Fields Lab Activity 1/8 Fri (A) Discussion of Magnetism
SOLUTION (17.3) Known: A simply supported steel shaft is connected to an electric motor with a flexible coupling.
SOLUTION (17.3) Known: A simply supported steel shaft is connected to an electric motor with a flexible coupling. Find: Determine the value of the critical speed of rotation for the shaft. Schematic and
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) You are standing in a moving bus, facing forward, and you suddenly fall forward as the
11-2 A General Method, and Rolling without Slipping
11-2 A General Method, and Rolling without Slipping Let s begin by summarizing a general method for analyzing situations involving Newton s Second Law for Rotation, such as the situation in Exploration
Analysis of forming- Slipline Field Method
Analysis of forming- Slipline Field Method R. Chandramouli Associate Dean-Research SASTRA University, Thanjavur-613 401 Joint Initiative of IITs and IISc Funded by MHRD Page 1 of 7 Table of Contents 1.
_CH01_p qxd 1/20/10 8:35 PM Page 1 PURPOSE
9460218_CH01_p001-010.qxd 1/20/10 8:35 PM Page 1 1 GRAPHING AND ANALYSIS PURPOSE The purpose of this lab is to investigate the relationship between displacement and force in springs and to practice acquiring
CIVL222 STRENGTH OF MATERIALS. Chapter 6. Torsion
CIVL222 STRENGTH OF MATERIALS Chapter 6 Torsion Definition Torque is a moment that tends to twist a member about its longitudinal axis. Slender members subjected to a twisting load are said to be in torsion.
Experiment Two (2) Torsional testing of Circular Shafts
Experiment Two (2) Torsional testing of Circular Shafts Introduction: Torsion occurs when any shaft is subjected to a torque. This is true whether the shaft is rotating (such as drive shafts on engines,
CONTACT MODEL FOR A ROUGH SURFACE
23 Paper presented at Bucharest, Romania CONTACT MODEL FOR A ROUGH SURFACE Sorin CĂNĂNĂU Polytechnic University of Bucharest, Dep. of Machine Elements & Tribology, ROMANIA s_cananau@yahoo.com ABSTRACT
Design Project 1 Design of a Cheap Thermal Switch ENGR 0135 October 13, 2016 Sangyeop Lee Jordan Gittleman Noah Sargent Seth Strayer Desmond Zheng
1 Design Project 1 Design of a Cheap Thermal Switch ENGR 0135 October 13, 2016 Sangyeop Lee Jordan Gittleman Noah Sargent Seth Strayer Desmond Zheng 2 Abstract This report will analyze our calculations,
Vertical bounce of two vertically aligned balls
Vertical bounce of two vertically aligned balls Rod Cross a Department of Physics, University of Sydney, Sydney NSW 2006, Australia Received 26 April 2007; accepted 14 July 2007 When a tennis ball rests
The bending moment diagrams for each span due to applied uniformly distributed and concentrated load are shown in Fig.12.4b.
From inspection, it is assumed that the support moments at is zero and support moment at, 15 kn.m (negative because it causes compression at bottom at ) needs to be evaluated. pplying three- Hence, only
CHAPTER -6- BENDING Part -1-
Ishik University / Sulaimani Civil Engineering Department Mechanics of Materials CE 211 CHAPTER -6- BENDING Part -1-1 CHAPTER -6- Bending Outlines of this chapter: 6.1. Chapter Objectives 6.2. Shear and
Modeling Mechanical Systems
Modeling Mechanical Systems Mechanical systems can be either translational or rotational. Although the fundamental relationships for both types are derived from Newton s law, they are different enough
Physics 2211 ABC Quiz #3 Solutions Spring 2017
Physics 2211 ABC Quiz #3 Solutions Spring 2017 I. (16 points) A block of mass m b is suspended vertically on a ideal cord that then passes through a frictionless hole and is attached to a sphere of mass
Chapter 12. Nanometrology. Oxford University Press All rights reserved.
Chapter 12 Nanometrology Introduction Nanometrology is the science of measurement at the nanoscale level. Figure illustrates where nanoscale stands in relation to a meter and sub divisions of meter. Nanometrology
Friction. Modeling, Identification, & Analysis
Friction Modeling, Identification, & Analysis Objectives Understand the friction phenomenon as it relates to motion systems. Develop a control-oriented model with appropriate simplifying assumptions for
My Vision for Particulate Magnetic Tape in the Year 2015
My Vision for Particulate Magnetic Tape in the Year 2015 David E. Nikles Department of Chemistry and The University of Alabama MINT Fall Review, November 2001. Particulate Magnetic Tape in the Year 2015
Shafts: Torsion of Circular Shafts Reading: Crandall, Dahl and Lardner 6.2, 6.3
M9 Shafts: Torsion of Circular Shafts Reading: Crandall, Dahl and Lardner 6., 6.3 A shaft is a structural member which is long and slender and subject to a torque (moment) acting about its long axis. We
3.091 Introduction to Solid State Chemistry. Lecture Notes No. 5a ELASTIC BEHAVIOR OF SOLIDS
3.091 Introduction to Solid State Chemistry Lecture Notes No. 5a ELASTIC BEHAVIOR OF SOLIDS 1. INTRODUCTION Crystals are held together by interatomic or intermolecular bonds. The bonds can be covalent,
STRUCTURAL OPTIMIZATION OF A MATERIAL EXHIBITING NEGATIVE STIFFNESS
International Conference on Engineering Vibration Ljubljana, Slovenia, 7-0 September 05 STRUCTURAL OPTIMIZATION OF A MATERIAL EXHIBITING NEGATIVE STIFFNESS Zuzana Dimitrovová*, Jan Heczo, Helder C. Rodrigues
Question Figure shows the strain-stress curve for a given material. What are (a) Young s modulus and (b) approximate yield strength for this material?
Question. A steel wire of length 4.7 m and cross-sectional area 3.0 x 10-5 m 2 stretches by the same amount as a copper wire of length 3.5 m and cross-sectional area of 4.0 x 10-5 m 2 under a given load.
5. Forces and Free-Body Diagrams
5. Forces and Free-Body Diagrams A) Overview We will begin by introducing the bulk of the new forces we will use in this course. We will start with the weight of an object, the gravitational force near
Physics A - PHY 2048C
Kinetic Mechanical Physics A - PHY 2048C and 11/01/2017 My Office Hours: Thursday 2:00-3:00 PM 212 Keen Building Warm-up Questions Kinetic Mechanical 1 How do you determine the direction of kinetic energy
Introduction to Continuous Systems. Continuous Systems. Strings, Torsional Rods and Beams.
Outline of Continuous Systems. Introduction to Continuous Systems. Continuous Systems. Strings, Torsional Rods and Beams. Vibrations of Flexible Strings. Torsional Vibration of Rods. Bernoulli-Euler Beams.
Physics for Scientist and Engineers third edition Rotational Motion About a Fixed Axis Problems
A particular bird s eye can just distinguish objects that subtend an angle no smaller than about 3 E -4 rad, A) How many degrees is this B) How small an object can the bird just distinguish when flying
EE C247B / ME C218 INTRODUCTION TO MEMS DESIGN SPRING 2014 C. Nguyen PROBLEM SET #4
Issued: Wednesday, Mar. 5, 2014 PROBLEM SET #4 Due (at 9 a.m.): Tuesday Mar. 18, 2014, in the EE C247B HW box near 125 Cory. 1. Suppose you would like to fabricate the suspended cross beam structure below
MATERIAL ELASTIC ANISOTROPIC command
MATERIAL ELASTIC ANISOTROPIC command.. Synopsis The MATERIAL ELASTIC ANISOTROPIC command is used to specify the parameters associated with an anisotropic linear elastic material idealization. Syntax The
(MPa) compute (a) The traction vector acting on an internal material plane with normal n ( e1 e
EN10: Continuum Mechanics Homework : Kinetics Due 1:00 noon Friday February 4th School of Engineering Brown University 1. For the Cauchy stress tensor with components 100 5 50 0 00 (MPa) compute (a) The
Unit 6 Forces and Pressure
Unit 6 Forces and Pressure Lesson Objectives: Mass and weight Gravitational field and field strength describe the effect of balanced and unbalanced forces on a body describe the ways in which a force may
Mechanics of Solids. Mechanics Of Solids. Suraj kr. Ray Department of Civil Engineering
Mechanics Of Solids Suraj kr. Ray (surajjj2445@gmail.com) Department of Civil Engineering 1 Mechanics of Solids is a branch of applied mechanics that deals with the behaviour of solid bodies subjected
Extra credit assignment #4 It can be handed in up until one class before Test 4 (check your course outline). It will NOT be accepted after that.
Extra credit assignment #4 It can be handed in up until one class before Test 4 (check your course outline). It will NOT be accepted after that. NAME: 4. Units of power include which of the following?
Consider a slender rod, fixed at one end and stretched, as illustrated in Fig ; the original position of the rod is shown dotted.
4.1 Strain If an object is placed on a table and then the table is moved, each material particle moves in space. The particles undergo a displacement. The particles have moved in space as a rigid bod.
Unit 21 Couples and Resultants with Couples
Unit 21 Couples and Resultants with Couples Page 21-1 Couples A couple is defined as (21-5) Moment of Couple The coplanar forces F 1 and F 2 make up a couple and the coordinate axes are chosen so that
Algebra Based Physics Uniform Circular Motion
1 Algebra Based Physics Uniform Circular Motion 2016 07 20 www.njctl.org 2 Uniform Circular Motion (UCM) Click on the topic to go to that section Period, Frequency and Rotational Velocity Kinematics of
Equilibrium in Two Dimensions
C h a p t e r 6 Equilibrium in Two Dimensions In this chapter, you will learn the following to World Class standards: 1. The Ladder Against the Wall 2. The Street Light 3. The Floor Beam 6-1 The Ladder
MEI Mechanics 2. A Model for Friction. Section 1: Friction
Notes and Examples These notes contain subsections on model for friction Modelling with friction MEI Mechanics Model for Friction Section 1: Friction Look at the discussion point at the foot of page 1.