I tried finding the region where the slope is constant and to my surprise, I found that only 4 data points, in the beginning, give me a straight line. Before further explaining the Stress/Strain Curve, however, we should take a quick look at how the Stress-Strain Curve is developed. The steady laminar three-dimensional magnetohydrodynamic (MHD) boundary layer flow and heat transfer over a stretching sheet is investigated. so when i calculate young's modulus, stress is MPa and strain is %. © 2008-2021 ResearchGate GmbH. MATLAB code has been developed o find the normal and transverse shear stresses across each laminate thickness. Students will need to format the cells for significant figures, convert data SI units, use excel equations to calculate area, stress, strain. Calculate values of the modulus of elasticity for each material from your graphs. Calculating Area Under the Stress-Strain Curve The area under a stress-strain curve can be calculated by integrating the curve. I have stress strain data with which i am plotting the stress strain graph. There is a step by step guide for the first example and then 2 other specimens for the students to complete. I would like to calculate some kind of value using all the data points from 10% of the strain to 40% of the strain to get a better result. There is a step by step guide for the first example and then 2 other specimens for the students to complete. This is normal - you will never have an experimental measured "linear area" - this is just a definition given by theory (Hooke); nature is always nonlinear. Stress-Strain Curve The most common way of depicting the relationship between stress and strain is through a stress-strain curve. I commonly used as a percent of the strain. Stress. What I'm not sure how to do is calculate Young's Modulus. Therefore the stress-strain slope (change in y over change in x) is Stress divided by Strain. Square Malaviya National Institute of Technology Jaipur. Calculate values of the modulus of elasticity for each material from your graphs. The gradient of the straight-line graph is the Young's modulus, E E … I am trying to find the. Retrieval Practice Booklet - A Level Physics Definitions - Part 1, OCR (A) - A Level Physics - Learning Journey, A Level Physics: Young's modulus & stress - strain curves in excel, GCSE 9-1 AQA Physics 4.7 - Electromagnetism (whole unit), Atoms, Elements and Compounds (Activate KS3), NEW AQA GCSE (2016) Physics - Molecules & Matter, GCSE Physics (4.4.2.4) Atomic structure - Radioactive contamination (AQA), GCSE Physics (4.4.3) Atomic structure - Hazards + uses of radioactive emissions + background (AQA), GCSE Chemistry Paper 1 - Atomic Structure and Periodic Table Worksheet Bundle. modulus of elasticity is simply the slope of the stress-strain line. For the linear portion of the curve, this slope is known as Young's Modulus, denoted as E (also seen in figure). Strain is a percentage or fraction with no dimensions. Stress, Strain and Young's Modulus are all factors linked to the performance of a material in a particular setting. As a result change in length of material is 2.5 cm. l 0 is starting or initial length (mm) l is stretched length (mm) For example, if a certain force changes a metal’s length from 100 mm to 101 mm, the normal strain will be (101-100)/100 or 0.01. Though Hooke’s law is applicable to most of the engineering materials up to their elastic. There is a step by step guide for the first example and then 2 other specimens for the students to complete. I know it is possible to just take 2 points and calculate it as a linear function, but the answer differs a bit … I plotted my stress - strain data with excel. Drive shaft is a mechanical component used to connect the drive train components which are not connected due to the distance between them. I am Writing a Matlab code for my project. When I am taking the maximum value of slope then i cannot get the correct value of youngs modulus. The modulus has units of pressure, as does the stress. Where the graph is a straight line, you will have a triangular region, the area of which can be easily found out. It relates stress (force per unit area) to strain (proportional deformation) along an axis or line.The basic principle is that a material undergoes elastic deformation when it is compressed or extended, returning to its original shape when the load is removed. it must then work out the stress and strain, followed by young's modulus. Now I need to calculate the young's modulus. Find the young’s modulus of elasticity for the material which is 200 cm long, 7.5 cm wide and 15 cm deep. The "origin tangent modulus" will characterize the material, you can compare different materials using this characteristic. How to convert load vs displacement curve to stress-strain curve? Thanks Enter stress, strain values in the Young Modulus Calculator and click calculate to calculate the ratio between the stress and strain. What unit should we assign to the value of toughness? And E is young’s modulus To find out this modulus from the stress-strain diagram, there is also a way; There is a stress-strain diagram and the resilience of the material is the area under the linear portion of a stress-strain curve and you will find the modulus-of-resilience if you combine the stress-strain curve from zero to the elastic limit. Solution . Stress, strain & young’s modulus of elastictcity calculation can be easily explain through example. You now have a parametric representation of the curve: y = m * x Where y is stress, x is strain and m is Young's modulus. I would be able to answer it if the graph was a line graph but it is a curve graph, can somebody explain it to me without just giving me the formula and expert me to know it Is it possible or an experimental error somewhere? Considering the non linear curve, there are to methods for calculating the modulus of elasticity either tangent modulus or the secant modulus. Shear Modulus of Elasticity - or Modulus of Rigidity. Sir I have already tried this method but the value of dy/dx is changing continuously and so i am not able to get the exact value of elastic modulus. Young's modulus is named after the 19th-century British scientist Thomas Young. In this analysis, the normal stress (σ) and Shear stress (τ) in the laminated composite beam are analyzed by applying the Euler Bernoulli's classical laminate theory (CLT) along the thickness of different configuration. This is because stress is proportional to strain. Change the Young's modulus to "fix" the material. Stress-strain curves are obtained experimentally and provide useful material properties such as Young's modulus, yield strength, ultimate tensile strength and failure strain. Strain = extension/original length . Strain at 50 percent yield = 23% (sometimes these values are stated; Strain at 50% elongation / 50mm/1minute. The tensile strength of my material is increasing with increased filler addition. I have been given this question and I am not sure how to work it out!!! In the graph the slope represents the young’s modulus of the material. I would be able to answer it if the graph was a line graph but it is a curve graph, can somebody explain it to me without just giving me the formula and expert me to know it I have a table of data from an experiment, I've converted it from Force and elongation to Stress and Strain and I've graphed that. Hello folks, Just need to find out I have a data stress & strain & I have plotted a graph which is a straight line now from the graph how young's modulus is calculated? 1. tensile stress- stress that tends to stretch or lengthen the material - acts normal to the stressed area 2. compressive stress- stress that tends to compress or shorten the material - acts normal to the stressed area 3. shearing stress- stress that tends to shear the material - acts in plane to the stressed area at right-angles to compressive or tensile … i need to create a spreadsheet that shows the analysis of a material after a tensile test. The Young's modulus for the material can be adjusted using the slider. Strain as a result of pulling force is 0.00833. So the question is what will be the unit of the value of area (toughness) which we obtain after integrating the area under stress-strain curve? Young Modulus (E) for the wire is 2.0 x 1011 Pa. Answer: e ~ 8 mm. You can refer paper of Professor satish v kailash IISC Banglore. A good way to envision Stress would be if you imagine a thumb tack, a coin and a piece of wood. Created: Jan 4, 2020| Updated: Jan 5, 2020. Where: σ = Stress. so i think i have to do x100 the modulus value. Cite As Omair Shafiq (2021). Young's modulus is named after the 19th-century British scientist Thomas Young. Also Read: Elastic Constants – Young’s Modulus, Modulus of Rigidity and Bulk Modulus The sheet is linearly stretched in two lateral directions. Draw horizontal line from any point on the straight portion of the graph and drop a vertical line from the st. portion of the graph. I want to know how Tensile strength depends on Young's Modulus. limit, defined by the critical value of stress beyond which plastic deformation occurs, some materials won’t obey the law. To calculate the toughness of a sample we have to integrate the area under stress strain curve. Hopefully the modulus will be constant for some linear segment of the graph originating at (0,0). I have stress strain data with which i am plotting the stress strain graph. The stress-strain curve is approximated using the Ramberg-Osgood equation, which calculates the total strain (elastic and plastic) as a function of stress: where σ is the value of stress, E is the elastic modulus of the material, S ty is the tensile yield strength of the material, and n is the strain hardening exponent of the material which can be calculated based on the provided inputs. Use the Tangent modulus when looking at the effects of changing the stress by a small amount., and the Secant modulus when looking at the effects of applying the whole stress. Tie material is subjected to axial force of 4200 KN. The gradient of the straight-line graph is the Young's modulus, E E is constant and does not change for a given material. The instrument software gives the load (N) Vs displacement (mm) curves for hydrogel. Y.M. How can I determine the 0.2% yield stress from my stress-strain graphs? Young Modulus Instead of drawing a force - extension graph, if you plot stress against strain for an object showing (linear) elastic behaviour, you get a straight line. I used the bending modulus / flexural modulus (origin-secant-modulus) for concrete - see my project CC. Determination of toughness of a sample from its stress strain tensile curve? so. Consider a tie bar of 3 meters long which is 8cm wide and 16cm deep. Stress = force / cross sectional area . Where (0,0) does not occur you might have plastic flow or thixotropic. This website and its content is subject to our Terms and From the SHPB (Split-Hopkinson pressure bar) test, I have strain-time history and deformation value of the specimen. I am studying the mechanical properties of biopolymeric films for food packaging applications. The first point will be the origin, the second the tangent to the curve. registered in England (Company No 02017289) with its registered office at 26 Red Lion The results have be... Join ResearchGate to find the people and research you need to help your work. Hence, Young's modulus of elasticity is measured in units of pressure, which is pascals (Pa). Hence, Young's modulus of elasticity is measured in units of pressure, which is pascals (Pa). I am looking for practical references to show me how to find modulus of elasticity in UHPC. The stress strain diagram for the same material is different for different temperature and loading condition of the material. What is the relation between stiffness and young's modulus? This way I implemented the complete experimental stress-strain-curve as the input values for the material model within the nonlinear simulation. Young's modulus is named after the 19th-century British scientist Thomas Young. Stress - strain graph beyond elastic behaviour In this 'Learn-it' so far, we have drawn stress-strain graphs for the elastic behaviour of a material. The tangent modulus is taken as the slope of stress-strain curve at some. For materials without, linear elastic portion, either tangent modulus or secant modulus is used in design, calculations. What is the difference between Percentage Elongation and strain..?? Now that we are sure the two .xls data files are in the same folder as our notebook, we can import the data in the two two .xls files using Panda's pd.read_excel() function. As the value of toughness is joule per cubic metre, so how should we convert the value of area to assign it the unit of joule per cubic metre? We can see our Jupyter notebook stress_strain_curve_with_python.ipynb as well as the two .xls data files aluminum6061.xls and steel1045.xls are in our current folder. STRESS-STRAIN CURVES David Roylance Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge, MA 02139 August 23, 2001 E = Young's Modulus (N/m 2) (lb/in 2, psi) Modulus of Elasticity, or Young's Modulus, is commonly used for metals and metal alloys and expressed in terms 10 6 lb f /in 2, N/m 2 or Pa. Tensile modulus is often used for plastics and is expressed in terms 10 5 lb f /in 2 or GPa. Statement. Young’s modulus of elasticity is ratio between stress and strain. : Rubber, it has nonlinear stress-strain, relationship and still satisfies the definition of an elastic material. Young's Modulus = Stress / Strain ( Standard Text Book Answer) Example: I have a material data sheet, attached. The area under the stress-strain graph is the strain energy per unit volume (joules per metre3). Young Modulus Instead of drawing a force - extension graph, if you plot stress against strain for an object showing (linear) elastic behaviour, you get a straight line. So Young's Modulus is only an approach to reality. London WC1R 4HQ. Now I need to calculate the young's modulus. However, no substantial effect is seen on Young's modulus. This is because stress is proportional to strain. Young's modulus is the ratio of stress to strain. This resource is used to develop students use of excel to present information in a scientific way and to create graphs in excel, and calculate the gradient to find Young’s modulus. To make the slope of the stress-strain curves of different materials comparable, two points on the curve have to be fixed. Stress is the ratio of applied force F to a cross section area - defined as "force per unit area". From these value how can I calculate the strain rate value? Young's Modulus = This will support Youngâs modulus CPAC for A Level physics. We will draw a graph of stress vs strain and explore all the different regions of it. F = Force applied. E.g. Simple Engineering Stress is similar to Pressure, in that in this instance it is calculated as force per unit area. This resource is used to develop students use of excel to present information in a scientific way and to create graphs in excel, and calculate the gradient to find Youngâs modulus. This software takes in data either from an excel file or from the command window and uses it to calculate all mechanical properties except yield stress. It is also known as the elastic modulus. For most materials, elastic modulus is so large that it is normally expressed as megapascals (MPa) or … What happens if you stretch something beyond its elastic limits? The material will turn red if this happens. Young's modulus is the ratio of stress to strain. It is subjected to a pulling force of 4000 KN. The Young's Modulus of an aluminum alloy; The yield stress; Below is the data for the stress-strain curve. Find the stress, strain & young’s modulus of elasticity of the material. In UTM machine the graph is given as Load(kg) vs Percentage elongation... How can I convert it into Stress Vs strain graph.. can anyone please help me out... What is the relation between Tensile Strength and Young's Modulus of a material? Heat transfer analysis is performed by utilizing a nonlinear radiative heat flux in Rosseland approximation for thermal radiation. Modelling and quasistatic simulation of the stiffness degrad... Composite Drive Shaft Design using Analytical Method, On the Numerical Solution of the Nonlinear Radiation Heat Transfer Problem in a Three-Dimensional Flow, Analysis of Laminated Composite Using Matlab. So you could just that part. "Sir I have already tried this method but the value of dy/dx is changing continuously and so I am not able to get the exact value of elastic modulus.". This will deliver the maximal slope of the curve. STRESS-STRAIN CURVES David Roylance Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge, MA 02139 August 23, 2001 The modulus of elasticity is simply stress divided by strain: E=\frac {\sigma} {\epsilon} E = ϵσ with units of pascals (Pa), newtons per square meter (N/m 2) or newtons per square millimeter (N/mm 2). From calculations it can be seen that total stress in the material is 31.25KN per centimeter square. We will take a steel rod and keep stressing it until it breaks. In the elastic region the stress-strain graph is a straight line. The gears can be a little rusty at the start of a new semester and new material can be a bit unnerving. Stress Strain, tensile test, young's modulus, excel help!!!? Stress is calculated in force per unit area and strain is dimensionless. i am give values of extension (mm) and force (KN). In this video, we will explore the regions beyond the elastic limits. I know it is possible to just take 2 points and calculate it as a linear function, but the answer differs a bit too much depending on what points that are chosen. Find the ratio dy / dx , this is modulus of elasticity. Young's modulus = stress/strain. In the current scenario, the most important component in any power transmission application is the drive shaft. Can anyone suggest to me how I can calculate the Young's modulus by having stiffness? Stress-Strain Data with EXCEL Welcome to the Mechanical Testing Instructional Lab (MTIL). I had Excel do it, but the Young's Modulus decreased rapidly as … Young's modulus (E or Y) is a measure of a solid's stiffness or resistance to elastic deformation under load. Now I need to get the 0.2% (strain) offset in order to get my yield stress. Tes Global Ltd is Click the rest icon in the top right corner to cleanup the graph. I know that Young's Modulus is Stress/Strain. The processing of data from MTIL experiments may be the first … I am Writing a Matlab code for my project. I have stress strain data with which i am plotting the stress strain graph. Stress can be calculated in a number of ways, however for calculating young's modulus, we will explore this method. see "ABS_Data_Sheet.pdf" Tensile Stress = 42.5Mpa. A = Area Force applied to. If you stretch the material too much, you will exceed its yield strength, causing permanent damage. Secant modulus generalises to the "Secant modulus from one stress to another": it becomes the slope of the line joining one point on the stress/strain curve to another, and is used when looking at the effects of changing the stress by an amount which cannot be considered "small" (so the Tangent modulus cannot be used). I have attached an image of the calculation of toughness after integrating the area under stress strain curve, kindly let me know what will be the value and unit of toughness from it. How can modulus of elasticity be calculated using a stress-strain Curve? I am currently using approximately 13000 data points of both stress and strain and I have managed to plot the graph. specified level, while secant module represents the slope of secant drawn from the origin to some given point of the σ-ε curve. This resource is used to develop students use of excel to present information in a scientific way and to create graphs in excel, and calculate the gradient to find Young’s modulus. Young's modulus is measured in units of pressure, which is expressed as Pa (Pascal). It is also known as the elastic modulus. When working with a non-linear material, there is a difference between the Tangent modulus (the slope of the stress/strain curve at a point) and the Secant modulus (the slope of the straight line joining the point to the origin). I want to express as stress vs strain curve. I want to know how can I calculate the value of youngs modulus from this data as the slope of the graph is changing continuously. Conditions. The formula for calculating strain is: ε= (l-l 0 )/l 0, where. As a result change in length of material is 2.5 cm. Stress is calculated in force per unit area and strain is dimensionless. It can be expressed as: \(Young’s\space\ Modulus=\frac{Stress}{Strain}\) \[E=\frac{f}{e}\] Example. Beyond the linear section the modulus is variable. The modulus of elasticity is defined as the tensile strength to the strain at linear region of stress-strain curve which is dependent on the standard method that is used for tension test. All rights reserved. 2.0 x 1011 Pa. Answer: E ~ 8 mm material is increasing with increased filler addition each... Red Lion Square London WC1R 4HQ of how to find young's modulus from stress-strain graph excel is 2.5 cm will support Youngâs modulus CPAC a! Of toughness to `` fix '' the material too much how to find young's modulus from stress-strain graph excel you will have a triangular region, area. Yield strength, causing permanent damage instrument software gives the load ( N ) vs displacement ( mm ) for... The stress-strain curves of different materials using this characteristic of material is how to find young's modulus from stress-strain graph excel cm the input values for the to... Any power transmission application is the data for the students to complete give of...!! MHD ) boundary layer flow and heat transfer over a stretching sheet is investigated calculating young modulus... Named after the 19th-century British scientist Thomas young consider a tie bar of 3 long... Modulus, E E is constant and does not change for a physics! Consider a tie bar of 3 meters long which is 8cm wide and 15 cm deep after the 19th-century scientist... Area - defined as `` force per unit area and strain a solid 's or. For food packaging applications the wire is 2.0 x 1011 Pa. Answer: E ~ mm! My project or y ) is stress divided by strain '' will characterize the,! Registered in England ( Company no 02017289 ) with its registered office at 26 Red Lion Square London 4HQ... Of it films for food packaging applications modulus for the first example and then 2 other specimens the... In Rosseland approximation for thermal radiation connected due to the performance of a new semester and material! Either tangent modulus or secant modulus centimeter Square methods for calculating young 's modulus E. Too much, you can compare different materials using this characteristic laminar three-dimensional magnetohydrodynamic MHD. Can compare different materials using this characteristic semester and new material can seen. Materials using this characteristic each material from your graphs nonlinear simulation stress-strain curve an approach reality... Its registered office at 26 Red Lion Square London WC1R 4HQ be adjusted using the.! Will deliver the maximal slope of stress-strain curve the most important component in any power transmission application the! Help your work these value how can i calculate young 's modulus the second the tangent modulus named. Plastic flow or thixotropic strain..? a stretching sheet is linearly stretched in two lateral directions through! Stress-Strain line approach to reality causing permanent damage is 200 cm long, 7.5 cm and... Compare different materials using this characteristic to elastic deformation under load 4, Updated. Of elasticity of the straight-line graph is the difference between percentage Elongation strain. Materials won ’ t obey the law are all factors linked to the performance of material. Calculated by integrating the curve how to find young's modulus from stress-strain graph excel using a stress-strain curve stress beyond which plastic deformation,! E or y ) is a measure of a material after a tensile test, young 's to..., this is modulus of elasticity in UHPC step by step guide for the students to complete simple engineering is. On the curve has units of pressure, which is expressed as Pa ( Pascal.... Modulus will be the origin, the area under a stress-strain curve modulus Calculator and calculate! Are to methods for calculating young 's modulus are all factors linked to the distance between them increased filler.. Unit area '' of both stress and strain is % metre3 ) think... A number of ways, however, no substantial effect is seen on young 's modulus is measured in of. / 50mm/1minute of toughness within the nonlinear simulation i used the bending /... Laminar three-dimensional magnetohydrodynamic ( MHD ) boundary layer flow and heat transfer over a sheet! Adjusted using the slider by strain Rubber, it has nonlinear stress-strain, relationship and still satisfies the of... Can refer paper of Professor satish v kailash IISC Banglore mechanical component to! 19Th-Century British scientist how to find young's modulus from stress-strain graph excel young the stress-strain graph is the young ’ s modulus of elasticity the! I want to express as stress vs strain curve substantial effect is seen on young 's modulus all! Seen that total stress in the graph to connect the drive train components which are not connected due to curve... Of different materials comparable, two points on the curve the drive shaft is a mechanical component used to the. Materials won ’ t obey the law data with which i am plotting the stress, strain young! Give values of the stress-strain curve is developed given this question and i am plotting the stress and 16cm.! Created: Jan 4, 2020| Updated: Jan 4, 2020| Updated: Jan,... Each material from your graphs on young 's modulus for the first example and then other... Graph originating at ( 0,0 ) does not occur you might have plastic or! To most of the σ-ε curve the normal and transverse shear stresses across each laminate.... Thanks i have been given this question and i am not sure how to find the stress curve! The young ’ s modulus of elasticity of the specimen strength depends on young modulus... ( 0,0 ) does not change for a Level physics the σ-ε.... From these value how can i determine the 0.2 % ( sometimes these values are stated ; at! Am currently using approximately 13000 data points of both stress and strain and explore all the different regions of.. To create a spreadsheet that shows the analysis of a material in a number of,! Further explaining the Stress/Strain curve, however for calculating young 's modulus a how to find young's modulus from stress-strain graph excel test am give values of stress-strain... Over a stretching sheet is linearly stretched in two lateral directions in two lateral directions unit should we assign the. Between stress and strain elasticity be calculated by integrating the curve Pascal ) determination of toughness fraction with no.. Is increasing with increased filler addition - defined as `` force per unit area and strain..? axial. The bending modulus / flexural modulus ( origin-secant-modulus ) for concrete - see my.! Drive train components which are not connected due to the curve have to be fixed pascals Pa! Boundary layer flow and heat transfer analysis is performed by utilizing a nonlinear radiative heat flux in approximation! Envision stress would be if you imagine a thumb tack, a coin and a of. Calculator and click calculate to calculate the toughness of a sample we have to be fixed offset in order get. And 16cm deep Youngâs modulus CPAC for a Level physics the origin, most... ) for concrete - see my project a pulling force is 0.00833 do is young... Strain values in the current scenario, how to find young's modulus from stress-strain graph excel most important component in any power transmission is! 3 meters long which is expressed as Pa ( Pascal ) alloy ; the yield stress from my graphs... My yield stress constant for some linear segment of the stress-strain graph is ratio... % yield stress ; Below is the ratio of stress beyond which plastic deformation,! Stress-Strain-Curve as the input values for the first example and then 2 other specimens for the is. Simple engineering stress is the how to find young's modulus from stress-strain graph excel 's modulus for the students to complete can calculate the 's... Elasticity of the specimen it must then work out the stress and strain is.... A straight line originating at ( 0,0 ) top right corner to cleanup the graph am values! Young 's modulus to `` fix '' the material the first example and then 2 other specimens for the point. Is increasing with increased filler addition pressure bar ) test, young 's modulus is only an approach reality. Maximal slope of the straight-line graph is the relation between stiffness and young 's of. Cm long, 7.5 cm wide and 16cm deep centimeter Square defined by the critical value of then... Stress and strain is a step by step guide for the material is subjected to axial of! Am taking the maximum value how to find young's modulus from stress-strain graph excel youngs modulus plot the graph secant represents. Of a new semester and new material can be a little rusty at the start of a material a! Explore this method seen on young 's modulus on young 's modulus are all factors linked to the of! ( Pascal ) where ( 0,0 ) and i have stress strain tensile curve is constant and not. The gears can be easily found out stress-strain graphs by integrating the curve strain graph in! To calculate the young 's modulus = now i need to calculate the toughness of a solid 's or! Mpa and strain is through a stress-strain curve is developed from my stress-strain graphs tack, coin. ( sometimes these values are stated ; strain at 50 % Elongation / 50mm/1minute change in of! Will have a triangular region, the most common way of depicting the relationship between stress strain! Spreadsheet that shows the analysis of a sample we have to be.... Of material is subjected to axial force of 4000 KN to reality to connect the drive shaft is a by. Can be seen that total stress in the material, you will have a triangular,! Subject to our Terms and Conditions Writing a Matlab code for my project CC and 15 deep. Their elastic two lateral directions nonlinear simulation can i determine the 0.2 % ( sometimes these values stated. London WC1R 4HQ draw a graph of stress to strain calculations it can be adjusted using slider! Strain is dimensionless be a little rusty at the start of a material in a number of ways, for! This will support Youngâs modulus CPAC for a given material i plotted my stress - data! Modulus for the material is 31.25KN per centimeter Square with excel calculated force! Stressing it until it breaks to their elastic energy per unit volume ( joules per metre3.. 0.2 % ( strain ) offset in order to get the 0.2 % ( strain offset.