What is Young's modulus: Definition and 189 Discussions

Young's modulus



E


{\displaystyle E}
, the Young modulus, or the modulus of elasticity in tension, is a mechanical property that measures the tensile stiffness of a solid material. It quantifies the relationship between tensile stress



σ


{\displaystyle \sigma }
(force per unit area) and axial strain



ε


{\displaystyle \varepsilon }
(proportional deformation) in the linear elastic region of a material and is determined using the formula:




E
=


σ
ε




{\displaystyle E={\frac {\sigma }{\varepsilon }}}
Young's moduli are typically so large that they are expressed not in pascals but in gigapascals (GPa).
Although Young's modulus is named after the 19th-century British scientist Thomas Young, the concept was developed in 1727 by Leonhard Euler. The first experiments that used the concept of Young's modulus in its current form were performed by the Italian scientist Giordano Riccati in 1782, pre-dating Young's work by 25 years. The term modulus is derived from the Latin root term modus which means measure.

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  1. D

    Young's Modulus Question: stretch of a wire

    Homework Statement A force stretches a wire by 2mm. A second wire of the same material and with the same area of cross-section and twice the length is also stretched by the same force. What will its stretch be? Homework Equations F= (YA/L)ΔL The Attempt at a Solution F, Y, and A are all...
  2. ezioauditore

    Sag in wire due to a weight (given the Young's modulus)

    Homework Statement A mild steel wire of length 1 m and cross-sectional area 0.5*10^-2 cm^2 is stretched within elastic limit horizontally between two pillars.A mass of 100 g is suspended from mid-point.Depression at mid-point? Homework Equations Sag in metal rod is=WL^3/(4BD^3Y) where...
  3. B

    What is the relationship between stiffness and Young Modulus?

    What is the difference between stiffness and Young Modulus and how can you calculate the stiffness?
  4. J

    Calculating stress and strains for beam of applied force

    Homework Statement If I consider a force, which is applied to both ends of a rectangular beam to its cross section with dimensions w (width) and h (height) and I know the length of the beam is l and the force is parallel, how can I calculate the stress? Also, what if the force were parallel to...
  5. K

    Uniaxial Tension Test: Calculating Strain from Extension Data?

    I conducted a uniaxial tension test for a variety of materials but wasn't able to gather much useful axial strain data due to the extensometer continually slipping. I have axial strain data for the linear elastic region of the stress strain curve and I also have the extension of the crossbar of...
  6. C

    Centrifugal force and elastic deformation

    Homework Statement Consider a spring of natural length L_0 with constant k which rests on a horizontal frictionless surface. The spring is attached at one end to a fixed post and at the other end to a mass m. Suppose the spring is rotating around the post in a circle with angular velocity w...
  7. TheSodesa

    Maximum load that a 2mm steel cable can hold.

    Homework Statement A platform (m = 5,0kg) is suspended from 4 steel cables whose length is 3,0m and diameter 2mm. a) How much further will the platform sink if a mass of 50kg is placed on the platform? b) What is the maximum load that the wires can hold before breaking? Homework Equations...
  8. J

    Appying a force bar + Young's Modulus + Force Applied

    1. Homework Statement h = 17.2 cm A = 12.32cm2 E = 410 MPA Fapp = 6130 N 2. Homework Equations Stress σ = F/A where F is force applied and A is cross sectional area of side where force is applied Strain ε = ΔL/L where L is the length of the bar and ΔL is the change of length of bar Young's...
  9. S

    Calculating Bulk and Shear Modulus with Young's Modulus and Poisson's Ratio

    Hi Can any please help: My course work is asking for me to calculate the Bulk modulus and shear modulus for a material that has a Young's modulus of elasticity of 250GN m-2 and a Poisson's ratio of 0.32? Any help will be great thanks Simon
  10. R

    Is There a Connection Between Young's Modulus and Crystal Structure?

    Hello guys, does anyone know if there is a specific relationship between the modulus of elasticity and crystal structure/microstructure? I know that YM is basically derived from the chemical bonding, but how about the other two? As much as I know it should be not affected by the microstructural...
  11. Z

    Calculate Young's modulus and Poisson's ratio

    Hi, I was looking some exercices on internet about the poisson's ratio. I have just one question. How can i calculate the young's modulus and poisson's ratio when i know that a material is purely elastical. I calculate circonferential et longitudinal contraints and i have write the cauchy...
  12. benedict1

    How to calculate Young's Modulus for flat spring

    Hi, I have a question regarding calculating Young's modulus for a flat spring. I have a flat spring shown as the left one in the image. Now I fix the bottom of the spring and exert a force F on top of it and it bends for distance of d. Is there any way to calculate young's modulus for this...
  13. R

    Unraveling the Stress-Strain Curve: Find Young's Modulus & Yield Strength

    Homework Statement The figure shows the stress-strain curve for a material. The scale of the stress axis is set by s = 280, in units of 10^6 N/m2. What are (a) the Young's modulus and (b) the approximate yield strength for this material? Homework Equations E=stress/strain The Attempt at a...
  14. J

    Calculating Speed of Sound in Nickel using Atomic Properties

    Homework Statement From WebAssign: One mole of nickel (6.02e23 atoms) has a mass of 59 g, and its density is 8.9 g/cm3. You have a bar of nickel 2.44 m long, with a square cross section, 1.8 mm on a side. You hang the rod vertically and attach a 45 kg mass to the bottom, and you observe that...
  15. B

    How to calculate Young's modulus of layered cross section

    Given a rectangular prism that is composed of various horizontal layers made of different materials, how can one calculate the modulus of elasticity? Currently the materials used and their respective ratios have not been specified. We wish to determine this information using the results of...
  16. R

    How to plot stress - strain and work out the Young's modulus

    Homework Statement I have the following table Load 25 50 75 100 125 150 160 170 Extension 0.38 0.75 1.15 1.53 2.8 8.6 15 28 and I need to: 1. Plot the stress – strain or (load-extension) graph and determine (a) Approximate value of the elastic limit (b)...
  17. toforfiltum

    Why is My Young's Modulus Calculation Giving a Different Result?

    Homework Statement Homework Equations E= (F/A) x (L/ΔL) The Attempt at a Solution I know that since the material is the same, the Young modulus should be the same. However, when I try to find the ratio of the second wire to the first, I get the answer C. For the first wire, E= 4FL / d2Δl...
  18. G

    What force should be used to calculate Young's Modulus?

    If a rod with cross section area A and length L is lying on a smooth table with one end being pulled by f Newtons and other end by 2f Newtons. What force I can use in calculating Young's Modulus and why? my doubt is whether it will be 3N or 1.5N and why? Stretched length is given.
  19. B

    High strain rate testing using the SHPB -- Help please

    I am a part C mechanical engineering student and require some advice for my individual project, which is based on the high strain-rate testing of a particular glass filled composite material using a split-Hopkinson pressure bar (SHPB) experiment. I gathered the results on a SHPB test rig and...
  20. B

    Does Young's Modulus Change When Nano-Tubes Are Connected End-to-End?

    Homework Statement A nano-tube having cross sectional area A and length L extends ΔL when a force F is applied normally to one of the cross-sectional surfaces. Show that if N tubes are connected end-to-end the then Young's modulus of the fibre does not change. Homework EquationsThe Attempt at...
  21. W

    Young's modulus of a hanging wire

    Homework Statement A hanging wire made of an alloy of titanium with diameter 0.5cm is initially 6m long. When a 60kg mass is hung from it, the wire stretches an amount 1.44cm. A mole of titanium has a mass of 48g, and its density is...
  22. K

    What does Young's Modulus x 2nd Moment of Area Equal

    Hi all I need to find the relative stiffnes of certain I beams from here http://tsbluebook.steel-sci.org/EN/Browsers/Main.htm Im assuming all I need to do times the Youngs Modulus by the 2nd Moment of Area In my head I am making it more complicated than it should be so I hope this is all it...
  23. ErnieChicken

    Calculating Young's Modulus for a Cylinder with Given Pressure and Bulk Modulus

    Hey Guys, I am new to the forums but have seen you guys help a lot with pointing people in the right direction. Here is my problem: A Cylinder with a Volume of 8000m3 has a pressure of 80MPa, Bulk Modulus of 74 MPa. I need to calculate the Young s modulus and determine the material type. So...
  24. FerrariEngineer

    Temperature Effects of Young's Modulus for Copper

    Hello- I am running a simulation of a simple brazed copper assembly; brazed at 1050°C. I believe the Young's Modulus will drastically change after brazing at this temperature since the annealed state is "dead soft". My analyst colleague is using an annealed value for E of 15E-6 psi, which...
  25. K

    Finding Young's Modulus for Steel from two graphs

    Homework Statement Estimate the value for Youngs Modulus from the two following graphs: Graph 1: Plot a graph of depression in metres (D) against load in kilograms (M) Graph 2: Plot a graph of log_10(D) against log_10 of Length of cantilever. Homework Equations [/B] D = 4*L^3*m*g / Y*a*b^3...
  26. kelvin490

    Same E for true stress true strain?

    Before yield we know that stress/strain= E. Can we obtain the same E if we substitute true stress and true strain in the equation? Why
  27. K

    Determining Young's Modulus by Bending a Piece of Wood

    There is an experiment to determine the Young's Modulus of the wood which involves bending it. The equation used to calculate it is like this E=WX3/4ZDY3 Where D=amount of bending W=force (N) which causes the bending Z=width of the wood Y=thickness of the wood X=horizontal distance between the...
  28. R

    Anisotropic Modulus of elasticity and Poisson's ratio

    Hi, I have some experimental data and I am interested to use this data to calculated modulus of elasticiy (young's modulus) and Poisson's ratio. The material for which the data is given in an anisotropic material, therefore I need to calculate modulus of elasticity and poisson's ration is x,y...
  29. L

    Young's Modulus of a Composite

    Homework Statement Glass fibres in Nylon provide reinforcement. Young's modulus of glass fibre is 72.4GPa; Young's modulus of Nylon is 2.8GPa. If the Nylon contains 30% by volume glass fibres, what fraction of the force applied parallel to the fibre axis is carried by the glass fibre? (Assume...
  30. M

    Calculating Poisson's Ratio with a Modulus of Rigidity & Young's Modulus

    Hi, I'm wondering if someone can point me in the right direction with this question. A material has a modulus of rigidity of 100 GNm-2 and a Young's Modulus of 250 GNm-2. Calculate the expected value of Poisson's Ratio for the material. Poisson's Ratio is expressed as transverse strain / axial...
  31. ZetaOfThree

    Young's modulus for cubic Van der Waals crystal

    Homework Statement Calculate the Young’s moduli for Van der Waals solids with sc, bcc, and fcc structures.Homework Equations Definition of Young's Modulus $$Y=\frac{stress}{strain}$$ Total energy due to Van der Waals interaction: $$U_{tot}=\frac{1}{2}N(4 \epsilon) \left( \sum_j{ \left( \frac{...
  32. G

    Does Young's Modulus Vary with Changes in Size?

    Does Young's Modulus change with drastic changes in size? For example, suppose you exert a force on the micro scale or maybe even the nano scale. Would the same Young's modulus uphold at such a small scale?
  33. A

    Young's modulus of rubber sheet using the inflation technique

    A rubber sheet (thickness 0.2mm) was mounted in an open-type Ussing chamber (6mm aperture) such that hydrostatic pressure could be applied to one side and the resulting inflation of the membrane tracked with an OCT instrument (OCT: ocular coherence tomography). From the geometry of the membrane...
  34. R

    Young's modulus and temperature

    Hi, I'm doing an IB extended essay in physics (like a 4000 word investigation) and I'm looking to do it on Young's modulus- in particular perhaps how temperature effects it. Is this legit? Like does temperature have a significant effect, in such a way that if young's modulus decreased with...
  35. M

    Calculated Young's Modulus smaller than typical value (steel)?

    Homework Statement I carried out an experiment using a extensometer, had a range of values for the elongation and load. I calculated the value from the data and had 11GPa whereas it should be 200GPa. Do you know what could have gone wrong? Thanks a lot.
  36. M

    Calculating Young's Modulus from a range of values

    Homework Statement I don't need to give any information, I just need to know the best way to calculate E from a range of values for load and displacement given the length and diameter. I've calculate it for a few values and the value appears to decrease so I'm not sure where to take the value...
  37. A

    Young's Modulus of guitar string

    Homework Statement A guitar string of diameter 0.6 mm and length 0.82 m is subject to a tension of 153 N. If the string stretches an amount 0.36 mm, what is Young's modulus of the string? Homework Equations Y=Stress/Strain Stress=F/A Strain=Amount of stress/Original Length The Attempt at a...
  38. L

    Young's modulus, stretching question.

    Homework Statement Three separate members of steel, copper and brass are of identical dimensions and are equally loaded axially.Young’s moduli for the materials are: steel, 210,000 N/mm^2 copper, 100,000 N/mm^2 brass, 95,000 N/mm^2 If the steel member stretches 0.13mm, calculate the amount...
  39. T

    Calculating Young's Modulus with only deflection

    Homework Statement In a project in a summer engineering class I'm taking, I have been tasked with finding Young's Modulus with three different diameters of spaghetti: Thin (1.41 mm), Normal (1.73 mm), and Thick (1.89 mm). Although this is my first time ever attempting to try engineering...
  40. AJKing

    Young's Modulus: Vibrations in a rod

    Homework Statement From A.P. French, question 3-10. I'm having trouble decoding part b. /Do not solve/ please help me find what it is asking. ------- A metal rod, 0.5m long, has a rectangular cross section of 2mm2. (a) This question provided me with information to calculate young's modulus...
  41. AJKing

    Ultimate Strength vs. Young's modulus

    What is the threshold where Young's modulus stops being applicable, and ultimate strength becomes relevant?
  42. AJKing

    Young's Modulus; Extension of a wire

    Homework Statement This is from A.P. French, Vibrations and Waves, Problem 3-7 A wire of unstretched length l0 is extended by a distance of 10-3l0 when a certain mass is hung from its bottom end. If this same wire is [turned to be horizontal] and the same mass is hung from the midpoint of...
  43. A

    Young's modulus value of Ferrous Tungsten

    How can I get Young's modulus value of Ferrous Tungsten? Is it possible to get it from Young's modulus value of Ferrous and Young's modulus value of Tungsten?
  44. A

    Finding Young's Modulus of Ferrous Tungsten

    Homework Statement I want to know the Young's Modulus of Ferrous Tungsten. Homework Equations Is it possible to get the Young's modulus of ferrous Tungsten from Young's modulus of ferrous and Young's modulus of Tungsten? The Attempt at a Solution
  45. G

    Tensile stress, radius and Young's modulus

    Homework Statement An Aluminum cable of length 3.5m has 15,000 N tensile force acting on it if the wire is only allowed to be stretched by 1mm before it breaks, What must be the radius of the wire if the Young's modulus of Al is 6.9 x 10^10 N/m^2? I am also supposed to find the tensile...
  46. J

    Young's Modulus, Bulk Modulus, and Shear

    I'm dealing with a cylinder. The equation for the stress of each is Force / Area. What are the different areas for the equation in regard to young's modulus, bulk modulus, and shear modulus? Is the area Young's Modulus stress the area of circle face? What about for shear stress? Would the...
  47. C

    Understanding the Relationship Between Elasticity and Young's Modulus

    Homework Statement This is a rather conceptual question, but is there a difference between elasticity and young's modulus? I know that the young's modulus can also be stated as the modulus of elasticity, but is it incorrect to say that a substance with a higher young's modulus has a low...
  48. J

    Young's Modulus of Elasticity Problems -

    Young's Modulus of Elasticity Problems - URGENT Homework Statement Calculate Young's Modulus of Elasticity for the three materials using the graphs only. Stress (N/m2) Strain 70 0.06 100 0.11 150 0.22 200 0.35 220...
  49. R

    Calculating stress, strain and Young's modulus?

    After a fall, a 77 kg rock climber finds himself dangling from the end of a rope that had been 15 m long and 9.1 mm in diameter but has stretched by 2.3 cm. For the rope, calculate (a) the strain, (b) the stress, and (c) the Young's modulus. strain = ΔL/L stress = F/A Young's modulus =...
  50. M

    Young's Modulus of a single crystal specimen?

    Does a single crystal specimen have a smaller Young's Modulus than a polycrystalline specimen? I think a single crystal would have a lower elastic mudolus since it has less grain boundaries and probably less dislocations than a polycrystalline specimen. I'd appreciate any ideas thanks
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