2.7Material Properties

Materials are defined by inputting their properties. These materials can then be assigned to the various members. A DEFAULT material, whose properties are assigned to all the members that do not have any materials assigned to them, can also be defined. Each material has the following properties

Material density, d, is the unit weight of the material. It is used to calculate the self weight of the members.

Modulus of Elasticity, E, represents the behavior of a material in the linear region of its stress-strain curve.

Poisson’s Ratio, v, is the ratio of the strain in the lateral direction to the strain in the axial direction. A typical value is 0.20 for concrete, 0.30 for steel, and ranges between 0.25 and 0.35 for most metals.

Thermal Coefficient, a, is a measure of the degree of expansion or contraction of a material when subjected to a unit change in temperature. This coefficient is needed when temperature loads are to be considered.