ABSTRACT
In the codes on design of reinforced-concrete structures, the allowable stress design is called working stress design, and the Load and Resistance Factor Design is called strength design. Mechanical properties of a material are determined by the stress-strain diagram obtained through axial tension and compression of specimens on testing machines. If in such testing a material exhibits a large tensile strain beyond the elastic limit, then it is called ductile; on the chance of a large compressive strain beyond the elastic limit with no splitting or cracking, a material is called malleable. Occurrence of a plastic hinge in a statically determinate beam means an exhaustion of its bearing capacity; when continued, a small increase of load causes collapse. The collapse of such a member, which has a character of unlimited change of length, occurs when the normal stress in a cross-section reaches the yield strength.
