Stress analysis of structures is a complicated subject. The following stress analysis Methods are used:

The basic requirement in stress analysis is given below:

    Both the values "induced stress" and "allowable stress" are calculated and compared.

Stress analysis helps the designer to do a "Fail Safe" design. Design by rules was used in many situations. Design by analysis is based on stress analysis. The following types of stresses are considered: tensile stress, compressive stress, bending stress, bearing Stress, buckling stress and local stress.

Stress analysis uses infinitesimal elements. The Finite Element Method (FEM) use Elements of finite size. The following computer programs are used for stress analysis:

    The structures should be stable and strong. The stability of the structure is checked using the following equation (necessary condition):

      F x N - R - C ≤ M

Where ,

The necessary and sufficient condition for structural steel stability is given  below.

Figure - 7.1: Two Dimensional Trun

F = 2.0, N = 16, R = 2 x 4 = 8, C = 0, M = 24

F x W - R - C = 2.0 x 16 - 8 = 24 = m

Hence, Stable