What is Strain: Definition and 461 Discussions

In organic chemistry, ring strain is a type of instability that exists when bonds in a molecule form angles that are abnormal. Strain is most commonly discussed for small rings such as cyclopropanes and cyclobutanes, whose internal angles are substantially smaller than the idealized value of approximately 109°. Because of their high strain, the heat of combustion for these small rings is elevated.Ring strain results from a combination of angle strain, conformational strain or Pitzer strain (torsional eclipsing interactions), and transannular strain, also known as van der Waals strain or Prelog strain. The simplest examples of angle strain are small cycloalkanes such as cyclopropane and cyclobutane.

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  1. claraberner

    Mohr's Circle does y-axis = max strain or max strain/2?

    This isn't a problem assignment per-say, but for a lab calculation. In my mechanics of material's class, we learned that the radius of Mohr's circle is the maximum strain, but now in my application lab-based class, the video is saying the radius is equal to the maximum strain divided by 2. So...
  2. K

    Stress-strain graph-finding elastic strain energy

    Homework Statement Homework Equations [/B] stress = force/area strain = extension/original length Young modulus= stress/strainThe Attempt at a Solution [/B] Hi i hope you can read my handwriting. I solved task a already but even though i think i solved b correctly, the solution says...
  3. X

    Maximum and minimum tensile/compressive strain in beam

    Hi, I'm quite stuck on this past paper question and would really appreciate some help on it. Below I have attached the questions and solutions; it asks me to determine where the maximum tensile and compressive strain in the beam using the bending moment diagram (attached as separate figure...
  4. T

    Mechanical Principals -- Strain guages mounted on a cylinder

    Can anyone ratify if my answer is correct for the below. I've attached.
  5. E

    Pipeline bend calculation from strain gauge data

    Hi all, I'm doing a stress analysis and I’m considering 3 buried pipelines carrying oil. Vibrating wire strain gauges have been installed in different sections for a total of 468 strain gauges. These have been arranged on the surface of the pipelines 120°apart: This pipelines have...
  6. mertcan

    I Stress Strain Curve: How Is It Derived & Tested?

    hi, I am aware that stress strain curve involves some function which begins with linear part and continues with non linear part after a while. I consider that it is so complicated, but I really wonder how a stress strain curve is derived, what kind of tests are applied and how those tests are...
  7. W

    Stress and Strain Pressure Vessels

    Homework Statement E = 290 GNm-2 Yield Stress = 500 MPa Q. What pressure would a strain of 40 με indicate? Homework Equations Hoop Strain. εθ = 1/E (σθ − νσz) = 1/E (pr/t − ν(pr/2t). The Attempt at a Solution I am looking for some direction on how to determine the poisson ratio...
  8. vktsn0303

    Streamlines from strain rate tensor

    I was reading about strain rate tensors and other kinematic properties of fluids that can be obtained if we know the velocity field V = (u, v, w). It got me wondering if I can sketch streamlines if I have the strain rate tensor with me to start with. Let's say I have the strain rate tensor...
  9. RyuuJin

    A Gravitational waves: effect of frequency on strain

    Hi guys. I am having a little trouble understanding a few relations professor mentioned at lectures, regarding gravitational waves - flux of energy and strain. First one expresses how is the flux of energy F related to frequency of radiation f and inflicted strain h. And the second one is for...
  10. P

    I Can we consider strained crystals as periodic crystals in theory and practice?

    Are a strained crystal still crystal? How to prove it? Are the unit cells of the strained crystal still the periodic elementary building blocks of the transformed crystal? Does the transformed crystal own the same volume as that of the perfect crystal? Can we treat the strained crystal as the...
  11. Liquito

    Heavy Duty Trolley Plastic Bending & Strain Energy

    Homework Statement http://imgur.com/a/RoKVR The link above have the full problem I mostly have issue with Part (b) of the problem where am not familiar with and don't know how to solve that part. I was wondering if someone can put some light in the tunnel or provide a link where I can study...
  12. R

    Relationship of viscoelasticity, creep and strain

    Can someone explain the terms viscoelasticity, creep and strain and their relationship to each other? Especially the difference between creep and strain. Any help would be greatly appreciated, thank you!
  13. M

    Which strain tensor is used in Föppl–von Kármán equations?

    Hi, I have a question concerning the von Kármán equations. I want to better understand the compatibility relation. The wikipedia article states that: https://en.wikipedia.org/wiki/F%C3%B6ppl%E2%80%93von_K%C3%A1rm%C3%A1n_equations "The components of the three-dimensional Lagrangian Green strain...
  14. billy722

    Question about stress and strain of a fiber

    Homework Statement i can not find the N. what i can only found is: D0=0.02mm;V=0.25;E=10G Pa;A=π(0.02mm/2)2 ΔD=εshear×D0 εshear=εaxial×V εaxial=σaxial / E σaxial=N/A Homework EquationsThe Attempt at a Solution
  15. B

    Does strain rate ever decrease yield stress?

    I've been digging through literature the last few days, and I'm starting to wonder if increasing strain rate EVER decreases yield stress? I found anomalies which increase it with increasing temperature. But I cant' find the reverse, so I was wondering if it was possible?
  16. T

    What is strain? Why does DNA coil upon itself?

    I have been reading Lehninger's Principles of Biochemistry to understand DNA supercoiling (pg-930). Supercoiling is the twisting of a DNA upon itself and this happens when the two helically wound strands of DNA are either underwound or overwound. The book says that this act of underwinding or...
  17. electr

    Pressure and Strain: Calculation of Max Allowable Pressure

    Homework Statement A cylindrical vessel 2m internal diameter and 4m long has a wall thickness of 6mm. Strain gauges are installed on the vessel to measure hoop strain (see FIG 6). 1)What is the maximum allowable pressure if a factor of safety of 4 is to be used? 2 )What pressure would a strain...
  18. electr

    Stress & Strain: Calculate Forces, Diameters & Lengths

    Homework Statement The component shown in Fig 1 is made from a material with the following properties and is subjected to a compressive force of 5kN. Material Properties : Young’s Modulus of Elasticity – 200 GNm-2 Modulus of Rigidity – 90 GNm-2 Poisons ratio – 0.32 Calculate : (a) The stress in...
  19. Al_Pa_Cone

    What pressure would a strain of 40 µε indicate?

    Q6. A cylindrical vessel 2m internal diameter and 4m long has a wall thickness of 6mm. Strain gauges are installed on the vessel to measure hoop strain (see FIG 6). The Young's Modulus of the Material = 290 GN m^-2 The Yield Stress of the Material = 500 MPa The Questions are (i)...
  20. T

    B What is a good physical reference for microstrain?

    I can say that the distance between my knuckle and my finger joint is 1~ inch, that a baseball weighs ~1 lb, and ~60 joules is the feeling of dropping a bowling ball on your foot. I'd like to understand strain in this way, can anyone offer a common place reference? Also, I know strain is...
  21. kdunkzz

    Calculate tension and strain of wire

    Homework Statement A load of 1150 kg is suspended as shown in the figure. The angle θ1 = 57° and the angle θ2 = 36°. (a) Calculate the tension in all three wires (that is, the magnitude of the tension force exerted by each of these wires): Tension in left wire Tension in right wire Tension in...
  22. Metals

    B A statistical definition of Young's Modulus?

    Young's Modulus is usually defined as the intrinsic property of a material indicating it's stiffness, or it's ability to resist deformation. Though, it is measured in Pa, meaning it should have some statistical description. Spring constant, for example, can be define as the stiffness of an item...
  23. C

    Understanding Strain in Different Directions: Is AD = AC cos theta?

    Homework Statement In this question , I am not convinced that δAD = δAC cos theta Homework EquationsThe Attempt at a Solution , i think it should be δAC = δAD cos theta , am i right ? I think so because we normally get the non-vertical and non -horizontal line and then cos the angle or...
  24. C

    Understanding Shearing Strain: Explanation and Examples

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  25. C

    Strain in Different Directions: Understanding Tensile Forces on Cubes

    Homework Statement the tensile force is applied at x direction to the cube , the cube will decrease in size in y and z direction , right ? according to notes, the strain in x direction εx = σxy/ E , where σy = normal stress in y direction , [/B]Homework EquationsThe Attempt at a Solution...
  26. C

    Calculating Shear Strain: σx / E and -vσy / E

    Homework Statement for the stress applied at x direction , the tensile strain εx should be = σx / E , right ? and for the tensile strain εy should be = -vσx / E , am i right ? Homework EquationsThe Attempt at a Solution I think so because in 1.7.1.3 , εy = σy / E - vσx / E , and εx = σx /...
  27. G

    Compliance matrix from strain matrix, Matlab

    Homework Statement (I'm trying to replicate some results in an academic paper where they have calculated elastic properties of a crystal. Because I'm going to do a lot of similar time-consuming calculations following this one, I need to learn how to do them using a computer.) The compliance...
  28. C

    Is the Calculation of Strain Due to Own Weight Correct?

    Homework Statement for the elongation due to its own weight , i suspect the calculation of elonation due to its own weight is wrong ... Homework EquationsThe Attempt at a Solution I think it should be (3456.3825)(75) / (300x10^-6)(200x10^3) = 4320m = 4320x10^3 mm , right ? [/B]
  29. A

    I What is physicial interpretation of deviatoric strain rate

    How these properties are related to velocity fluid. The https://postimg.org/image/674a6sw4t/ https://postimg.org/image/674a6sw4t/ figure shows an area of Earth's mantle where upwelling of hot semi-liquid mantle is occurring in middle and then two downwelling currents on two sides (forming...
  30. C

    9 components of strain for a cubic

    Homework Statement why the strain of εxy , εxz , εyx , εzx , εyz , εzy is γ_xy / 2 , γ_xz / 2, γ_yx / 2, γ_zx / 2 , γ_yz / 2 , and γ_zy / 2 ? how to get that ?. Homework EquationsThe Attempt at a Solution Taking an example of εxy , what does γ_xy / 2 mean ? [/B]
  31. Wolfrider

    Traction/ Compression stress and strain exercise

    Hello everyone, could you help me with this exercise? I am stuck, and I can't find anything on the internet that solves this. Your help is very much appreciated :) 1. Homework Statement Circular steel bar, clamped at extremities. Two parts: A(ab)=800mm² A(bc)=400mm² L(ab)=...
  32. Mohamed_Wael

    Ansys non-linear stress strain curve

    If I am using a new material in ansys, let's say I assigned it as solid linear elastic and I assigned density, young's modulus and poisson's ration and then I applied large deformation for this material so that it should be experience non-linearity ...I wonder how Ansys can give the results...
  33. I

    How do I calculate the extension and strain at peak load?

    Homework Statement If a question gives us a max load with different extensions, how do I calculate the strain? For example: 1900KN=x mm 1900KN=x mm 2000KN=x mm 2000KN=x mm 2000KN=x mm 1900KN=x mm 1900KN=x mm Homework Equations strain= ΔL / L The Attempt at a Solution What I think is...
  34. B

    A Silicene Crystal Structure: Strain and Tight-Binding Model

    Crystal structure silicene is belows: Na=2; % Number of atoms Nbnd=8; % number of bands q=0.03; w=0.30; aa=2.28; a=3.86; Csoc=0; EL=0; POSx(1)=4.45714; POSy(1)=0; POSz(1)=0; POSx(2)=2.22857; POSy(2)=0; POSz(2)=0.46; a1x=a*sqrt(3)/2; a1y=-a/2; a2x=a*sqrt(3)/2; a2y=a/2; sho=0; for is=[0,-1,1]...
  35. A

    A Insert Strain on Graphene with Tight Binding Methods

    How to insert strain on graphene using tight binding methods? How strain can be applied in one of the x or y axis?
  36. C

    Calculate Stress & Strain from Length, Diameter & Load

    Unsure how to calculate in order to get the stress (N/mm2) and strain (%) if: a material has a length of 50mm diameter of 12mm Load: 11.5 kN Extension 0.025 mm Help on how to work this out would be very appreciated :)
  37. A

    A Drawing Band Structure of Silicene Under Strain Using Tight Binding Methods

    I have been drawing band structure silicene under strain using tight binding methods. How to change K points under strain? Matlab code is corrected?[ MATLAB code for the intended purpose as follows: close all clear all clc Na=2; % Number of atoms Nbnd=8; % number of bands q=0.1; w=0.30...
  38. R

    Deriving Strain in Cantilever Beam with Known Deflection

    I am trying to derive the strain at the base of a cantilever beam with a known deflection. I know the bending stress is equal to Mc/I, so the strain is Mc/IE, where c is the distance from the neutral axis. For a point load ,P, the strain would then be PL/IE. Since the deflection is known I...
  39. morganj2003

    LaTeX Is a latex balloon's maximum strain independent of thickness?

    Is latex balloon maximum strain independent of latex thickness? I have been in search of a latex balloon that is relatively small when deflated and very large when fully inflated. Standard balloons that reach the desired inflated dimensions are much larger deflated than I would like...
  40. Ravi Singh choudhary

    Stress strain diagram of mild steel -- gauge length made half

    All we know the usual stress strain diagram obtained from tensile test from universal testing machine. As modulus of elasticity is material property that means till proportional limit slope will not change. As it is not a force vs elongation curve that means there will be no re-scaling to be...
  41. C

    I Can "extremal" strain tensors be in the interior of the body

    I am new to elastic theory. I have a question about elasticity. We assume we have a body with no internal forces. Surface forces are applied on the border. Can we leave the elastic domain (reach the yield surface) in an interior point without leaving the elastic domain on the boundary? If no...
  42. Jazmin Urioste

    I Finding Maximum Strain with Cantilever Beam

    Hello, I am trying to establish what the moment of inertia is for this cantilever beam as well as the maximum strain. General formals preferred. Thank you
  43. R

    How Do You Calculate Shear Strain in a Crystal?

    I don't know how to solve this kind of problem: Given a crystal and its volume V. This Crystal is subjected to a shear stress making a slip plane (h k l ) in a slip direction [h k l]. Given also the lattice parameter a and slip plane spacing L, and the edge dislocation a/2 that passed halfway...
  44. G

    Strain of a wire tied with an angle in a beam

    Well, i have a cantilever beam where i have the displacement of the tip of the beam (y axis) data from a vibration of this beam. In the tip of the beam is a steel wire attached, pulling up the beam with an angle (30º for example). I want to know if exists a form to obtain the strain of the wire...
  45. G

    Correlating Displacement and Strain in a Cantilever Beam System

    Hi, Well i have a system with a excited (in y axis) cantilever beam. I struggling to obtain a expression that gives the strain based on the dislocation y. I know that the displacement of the beam is given by: Ya=PL^3/(3EI) but how i make a correlation between this and the strain of the...
  46. E

    Stress and Strain ratios in sheet metal?

    Hello! I'm having some trouble understanding stress and strain rations in sheet metal forming. I understand that they're constants, but how do you calculate them? Or are they usually given? Thank you!
  47. M

    Calculation of Permanent set out of stress strain relation

    Hi, I have been given a relation between stress and strain which is strain=(stress/70000)(1+(3stress/(1890)) the dia of round bar is 10mm and length is 3mm and that's all the data i have and I am required to find out permanent set.
  48. 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...
  49. R

    What are some approaches for estimating the work done up to fracture?

    Good day everyone! i have a problem dealing with the fracture analysis. We all know that the work done per unit volume is equal to the area under the curve of stress-strain curve or we can express it in terms of integral form, and if we're looking at necking point stress can be express in this...
  50. G

    Piezoelectric strain rate and frequency of applied voltage

    If one were to apply, for example, 60 Hz AC to a piezoelectric material, would the strain rate be 60 Hz? I am not entirely sure if I am using "strain rate" in its proper sense; I use it merely to describe what I imagine would be the rate at which the material expands and contracts while exposed...
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