Describe the Relationship Between Axial and Lateral Strain.

Chapter 8 Questions

Name: Lee Jie Min Jasmine, Ke Jun Yong Alan, Lim Kai Kiang, Ong Kim Liang Nicholas, Shankra s/o Krishna

Date: April 26, 2015

1. Describe the relationship between axial and lateral strain.

Axial strain – is the change in length, per unit length, of a member that is in a tension or compression stressed condition.

Lateral strain – always occurs with axial strain and is perpendicular to longitudinal.

The relationship between axial and lateral strain is that the number of molecules in the member does not change when elongation occurs, thus the width of the member must decrease. For example, if a load, P, is applied to a steel bar of cross-section, w, the length will stretch from L to L + ΔL, and the cross-section width will decrease from w to w - Δw. In addition, the relationship can be explained with Poisson’s ratio.

2. What is meant by "Modulus of Elasticity"?

When a material is subjected to a tension or compression load and the stress and strain are measured and are proportional to each other, the material is said to be elastic. When the load is removed an elastic material will return to its original dimensions. “Modulus of Elasticity” is the constant of proportionality, E.

It is also known as Young’s modulus, and an important property of a material. It measures the stiffness of the material. Large values of E show that the material is stiff and will have little strain for a given value of stress.

3. Describe elastic and plastic properties of materials.

When a sufficient load is applied to a metal or other structural material, it will cause the material to change shape. This change in shape is called deformation. A temporary shape change that is self-reversing after the force is removed, so that the object returns to its original shape, is called elastic deformation. In other words, elastic properties of materials are a change in shape of a material at low stress that is recoverable after the stress is removed. This type of...