Effect of Stress – Strain Relationship on the Elasticity Modulus and Moment Capacity

Abstract:The Effect of strain on the elasticity modulus and moment capacity ofmembers are studied using different types of stress strain relationships (linear,elasto-plastic, elastic perfectly plastic, bi-linear, tri-linear and other continuousmodels) for bending with or without axial loads using the steps of solution shownin the research.Generally in all cases inelastic modulus reduced with increasing the strainand stress level and significant decrease is occurred in the value of inelasticmodulus, the value of inelastic modulus reduces to about (50%) of its initial valuewhen the stress value within (0.4-0.5) of the yield strength. Effect of stress ratio(RF) and strain ratio (R) are also studied. Suitable equations are proposed toestimate the values of inelastic modulus and moment capacity