Principal Stresses and Strains:

You have already been introduced to simple states of stress. Stress Analysis is an essential requirement in the evaluation of strength, stiffness, deformations and safety of solids so that one may produce functionally efficient and economic designs. There is a big number of ways in which stresses are induced in solids (a few samples ones you have already study), which shall engage your attention in the subsequent units. we will be concerned with the analysis of a specified state of stress (defined in terms of stress components on chosen planes) which shall have a bearing on the analysis of strength & safety of solid components.

Objectives

You must be able to

• describe six stress components on mutually perpendicular planes at the requisite position,
• explain the principal stress and principal plane,
• recognize the plane of maximum shear stress,
• analyse the state of stress in combined bending & shear and combined bending & torsion, and
• Explain various theories of failure.