Formula for Calculating Tensile Stress?

Stress Strain, tensile test, young's modulus, excel help!!!?

• i need to create a spreadsheet that shows the analysis of a material after a tensile test. i am give values of extension (mm) and force (KN). it must then work out the stress and strain, followed by young's modulus. i am getting very confused on the formula's i try as none of them seem to work out. please help. thank you

• Answer:

  You work out the stress by dividing the applied force by the cross sectional area of the gauge length.You work out the strain by dividing the extension of the gauge length(due to the stress) by the gauge length and then Young's modulus is stress divided by strain.In practise,since specimens may initially be bent or contain internal stress.you work out changes in stress and strain at two places on the straight line section of the load/extension plot and calculate change in stress/change in strain as the modulus.