Strain Definition and 413 Threads

Hi I'm studying strain analysis using Mohr's circle. I have some problem using a star rosette to construct the circle. My problem lies with trying to identify the points which indicate the planes the rosette act on. Besides that, what is meant by "strain rosette with gauge X (gauge X being...

Hello All, I am trying to learn the theory of elasticity from Landau's book and from the very beginning I've run into trouble. As I learned it, a (0,2) tensor T_ij obeys the transformation law T_hk=T(dx_i/dx_h)(dx_j/dx_k). But I do not see how a strain tensor can be transformed in such a...

Are these two things the same? I'm looking at bioabsorbable copolymers with similar properties to the human acetabular labrum, but I can only find tensile strength values for the copolymers and tensile stress at break for the labrum. I've looked at the definitions of each it sounds like the...

I have a very fundamental doubt regarding the stress strain graph for many materials..Normally we plot strain ~stress in the graph..but it seems that stress is the independent variable and strain is the dependent variable..but still why nowhere i have found the curve as stress~strain..can...

When plotting a stress against strain graph is this the right equation that fits the form y=mx+c? I got (F/A)=y(dL/L) where F is force A is area y is youngs modulus dL is change in length and L is original length. The Y is F/A. The m is y and x is dL/l (in y=mx) is this correct? Thank you

Design a circuit that uses a stain gauge to create a voltage related to the strain experienced by the gauge. The strain gauge should remain electrically isolated from the ground. The DC common mode voltage should be minimized. Only stain-related signal to be measured does not have any...

Howdy ya'll, a relatively simple question, A circular bar 20mm in diameter and 1m long is subjected to an axial load of 50kN. Determine: (i) The normal stress. (ii) The normal strain. (iii) The elongation. Assume the material is steel with an Elastic Modulus of 200GPa. ok so i...

Hi Guys, So I am biting off more than I can chew with my latest project.. and looking for help. I am going to fabricate a kit car chassis, The suggested material is 1' x 1' steel box section but why? Could anybody help by suggesting the kind of calculations I would have to research...

using excel 2007, can the construction to determine the proof stress of a material not be done manually? if so, how?

Very simply put. Is it possible to determine bending stress in a beam without knowing the young's modulus of the material used? All equations I've seen seem to include in some form an E value ( young's modulus), which is used in conjunction with a stress value to evaluate the strain.

Currently I am studying the mechanical properties of artery tissue, and was tasked with determining if the tissue fails due to shear stress or shear strain. I have always worked under the assumption that they go hand in hand with each other, but the nature of this question obviously suggests...

In lab for our final project, we used a Wide Range Strain Indicator connected to strain gages on a part we machined to function as a scale. The Indicator device was much like this one: http://www.datasheetcatalog.org/datasheet/vishay/3800.pdf What units would the numbers be that we're...

This is a homework problem and I thought about putting it in the homework section bu since its very materials science specific I decided to put it here: For a transversely isotropic material, the “plane strain bulk modulus”, K23, is an engineering constant that is defined by the stress...

Hi, I have a solid cylinder to which I have strain gauges attached to measure axial and circumferential strains. My goal is to relate the circumferential strain to radial strain and then to calculate possion's ratio. Every time I try to work out the geometry of the problem I end up saying...

Homework Statement Hello, I've been given a question: The ultimate strength of a round steel rod is 560MPa. If a factor of safety is 6 is required, what is the maximum permissible load for the rod if it has a diameter of 6.9cm? If anyone can explain how to set up this...

do strain gauges need calibration

In strength of materials, we have to do a project using strain gages to measure a weight between 0 and 10 lbs with an accuracy of .1lbs. My group is using bending strain. We have a formula, S_{}b=\frac{F*L*6}{E*b*h}, where F is the weight applied, L is the length, E is the Young's Modulus, b...

Homework Statement The elastic limit for a type of material is 1.6 x 10^8 Pa.Determine the minimum diameter if a wire which is made of this material so that it can support a load of 100N without the stress exceeding the elastic limit. Homework Equations elastic limit=stress...

Hi All, I have a stress strain curve, which have strain(in/in) on x-axis and stress in Y axis(Psi). Here I want to conver the curve to stress(MPa) and strain (mm/mm). I know that Psi can be converted by multiplying the digit by 0.00689475729. But in this case I need to change the strain...

I am studying strain gauges at uni and was wondering if you could clarify for me how they may be used to measure mechanical strains in structures like towers, houses etc.. I know that it is possible to use a mechnical gauge that measures the development of a crack (see wiki)but I can't work...

I have been given a question to recap by my tutor as i find this topic fairly difficult. A steel column is 90cm long and 150mm diameter. If a hole 100mm diameter and 60cm long is bored out, calculate the total compression of the column when carrying a load of 1MN. Take the modulus of...

Homework Statement A 30kg sledge hammer strikes a steel spike of 2.30 cm diameter while moving at 20.9 cm/s. The hammer rebounds with a speed of 10.0 cm/s after 0.110 s. What is the average strain in the spike during impact? Mass of hammer = 30 kg Radius of Spike = 1.15 cm or 0.0115m...

hey everyone I am stuck on a problem and would appreciate any guidance you could give me. here is the question: Much as in exercise 8.1, the end of a .75-in-diameter rod is fixed to an immovable plate. the length of the rod is 18.0-in. A 50-lb weight is attached to a 16.0-in lever at the...

1. A 3.0-mm2 cross sectional area metal rod is stretched by 0.4 mm when a certain stretching force is applied to it. Another rod of the same length and metal but of a cross sectional of twice as large is stretched by the same amount of force. Calculate the stretching in the second wire. the...

The Lagrangian finite strain tensor is defined as: E_{i,j}=\frac{1}{2}\left(\frac{\partial x_k}{\partial X_i}\frac{\partial x_k}{\partial X_j}-\delta _{i,j}\right) Is it in Einstein Notation so that there is a summation symbol missing, i.e. would it be the same thing if one wrote it as...

I'm working on a problem involving the bending of a beam. The bending is a result of an expansion within the beam, rather than an external load. Basically, there is an expansion in the volume of one side of the beam and a contraction on the other side. I have therefore calculated a...

Hello, so here is my problem. Homework Statement I am given tensile data, which is displacement (mm) and load (kgf). also I am given width(mm), thickness(mm), gauge length (mm) and cross-head speed (mm/min). How do i make a stress strain curve from this? The Attempt at a Solution...

I've recently been researching how to measure strain using strain gauges. I came upon the subject of shunt calibration and hit a mental roadblock. From what I understand, shunt calibration simulates a strain across a strain gauge using a comparatively large resistor placed in parallel with...

Is simple shear same as rotational strain? or, is it a type of rotational strain?

Calibrating a strain gauge/thermistor? Hey guys, Im abit confused on the method of calibrating a strain gauge/thermistor, i know they both use a wheatstone bridge (resistance). At the moment i have gathered this information, Transducers and sensors which produce a change in resistance are...

Homework Statement Question: The strain state in a point is defined by the tensor: 0.9 0 0 0 -0.4 0.2 0 0.2 0.6 - Define principal strains and directions in the point - Explain how deforms the element shown in figure 2b (they just drew a cube on 3d axis) - Draw the principal directions...

Hi, I was wondering... if by heightening a sofa (150cm in length approx) from floor level by about 20-30 centimeters, would increase, or could potentially increase the strain in the centre of a sofa when people sit on it? I have a long sofa, that was raised and I notice that my sofa is sagging...

Homework Statement I want to convert the output of a strain gauge into an equivalent parellel binary word Homework Equations i need to list the process blocks in correct sequence and starting at the strain gauge The Attempt at a Solution Strain gauge- convert ohms to volts-...

http://www.ami.ac.uk/courses/topics/0123_mpm/images/met_mpm_imgb.gif http://i859.photobucket.com/albums/ab152/Greener1011/Untitledpicture.png First off I am sorry about the massive size. The top graph is how a stress strain graph of a metal should look. However i can't seem to think why Mpa...

Homework Statement I recently did a bending lab with a WB Strain Gauge in a bunch of different configurations. One measurement in particular is bothering me. Referring to the figure below, there are four strain gauges, Yellow, Orange, Black and Red mounted to a cantilevered beam with an...

Hello i am trying to convert the strain gauge readings i took in a lab from an I beam that was subjected to torsion. I am trying to convert the microstrain readings to stress and shear stress. I have the following information the Yield strength of the I beam and the youngs modulus but not the...

Ok, so what I am looking for, as the title suggests, is a strain gauge data acquisition board. Currently, we have been using all sorts of National Instruments stuff to obtain our goals. To this point they have worked fine, but now we need to seriously downsize for a new lab device we are...

The shear modulus of aluminum is 2.4 × 1010 N/m2. An aluminum nail of radius 7.5 × 10–4 m projects 0.035 m horizontally outward from a wall. A man hangs a wet raincoat of weight 25.5 N from the end of the nail. Assuming the wall holds its end of the nail, what is the vertical deflection of...

1. A copper wire has length 200cm and radius 0.40mm. A mass of 1.00kg is suspended from the end and allowed to come to rest. The Young modulus of copper is 130Pa. Calculate: a) the stress b) the strain c) the extension d) the elastic energy stored Repeat the calculations for the case of a carbon...

I need to find several cheap strain gauges. I was able to find some at Mouser for several hundred dollars, but that is way too much. I wasn't able to find any at all at digikey or several other suppliers whom I've never heard of. Do cheap strain gauges even exist?

There's this equation e_{ij} = \alpha_{ij}\DeltaT + d'_{ijk}E_{k} + Q'_{ijk}H_{k} + s_{ijkl} Sigma_{kl}, which is the strain tensor I'm asking about. All I want to know is what the component d'_{ijk}E_{k} is called and what its physical meaning is. Thanks in advance

I've just been given a quote on some strain gauges I'm after and the adhesive but I've got a 4-6 week wait from this supplier and I want somewhere else to compare against price wise. If I can get them sooner rather than later it would be cool too. Any suggestions? My searches in Australia...

I'm wanting to measure the torque output of a cyclist by measuring the shear force induced in the crank arms. I've done some calculations for the minimum amount of strain that I'll want to pick up and it is around 6e-6 m/m. I'll be using a full wheatstone bridge with a constant voltage...

Homework Statement Given two wires of gauge length 100mm and 200mm They are loaded to fracture in tension The 100mm sample extends by 15mm The 200mm sample extends by 25mm. I need to use this information to calculate the nominal strain at which necking commences in the wires Homework...

Any one can help me solving this pleasezzzz http://i49.tinypic.com/2vkm2r8.jpg" My attempt At A-B There is No load so dM/dP= 0 and dU/dP= 0 At B-C M = -px - wx.x/2 dM/dP= -x dU/dP = Wx^4/8EI At C-D M = -Wb + Px dM/dP = x dM/dP = -Wbx^2/ 2EI When i include all vaues...

I need to draw a stress and strain graph. New to physics, so would like to know if i am on the right line and require a bit of help for the last few questions These are the values I have: Diameter - 10.02mm Original Length - 50mm Extension -10mm Diameter After Test - 6.76mm Max Load -...

Hello to everyone, my question is how to find strain in rectangular cantilever beam applying point load at some point. I am not getting formulas for that..Please save me from this. Its very urgent for me.

given the following points of the stress strain graph and knowing that the stages are defined linear σ=Eε uniform plastic σ=Kδ2 necking σ=αδ where ε is an elastic strain and δ plastic strain find the values of the constants E K n α using the given data i plotted σ(ε) and got the...

in the following problem i know that ΔT=120 now the maximum deflection is 0.5mm so i looked for the total deflection had there been no restrictions ΔL(aluminium)=300*(23e-6*120)= 0.8280 ΔL(st steel)=250*(18e-6*120)= 0.5400 this is clearly more than the maximum deflection of 0.5-...

Homework Statement A copper rod of 2 meters is joined to a steel rod with length (ls) and with cross sectional area of 1.0cm2 and 2.0cm2 respectively the compound rod is subjected to an equal and opposite force of 3x104N. Find: a) The length of the steel rod if the elongation of the steel...