# Strain, Stress, and Poisson’s Ratio

When a material receives a tensile force P, it has a stress? that corresponds to the applied force. In proportion to thestress, the cross section contracts and the length elongatesby? L from the length L the material had before receiving thetensile force (see illustration in Fig. 1) below. The ratio of the elongation to the original length iscalled a tensile strain and is expressed as follows: See the lower illustration in Fig. 1. If the materialreceives a compressive force, it bears a compressivestrain expressed as follows: For example, if a tensile force makes a 100mm longmaterial elongate by 0.01 mm, the strain initiated inthe material is as follows: hus, strain is an absolute number and is expressedwith a numeric value with x10 -6 strain, ?? or ?m/msuffixed. Based on Hooke’s law, the relation between stressand the strain initiated in a material by Choose The Best Hair Drug Test hair drug test shampoo On the Market! – If you have an upcoming hair follicle test, then you are probably frantically searching for the best shampoo and Conditioner on the market. an appliedforce is expressed as follows: Stress is thus obtained by multiplying strain by theYoung’s modulus. When a material receives a tensileforce P, it elongates in the axial direction whilecontracting in the transverse direction. Elongationin the axial direction is called longitudinal strain andcontraction in the transverse direction, transversestrain. The absolute value of the ratio between thelon and gituding strain transverse straln is calledPoisson’s ratio, which is expressed as follows: 