Types of applied stress:

Stress intensity inside the body of types is expressed as one of three basic categories of internal load. They are known as tensile, compressive, and shear.  Figure described the various categories of stress. Mathematically, there are only two categories of internal load since tensile and compressive stress might be regarded as the positive and negative versions of the similar categories of normal loading.

Therefore, in mechanical design, the response of elements to the two conditions could be so different in which it is better, and safer, to regard them as separate categories.

As illustrated in Figure 1, the plane of a tensile or compressive stress lies perpendicular to the axis of operation of the force from which it originates.  The plane of a shear stress lies in the plane of the force system from which it originates.   It is essential to keep these differences quite clear both in mind and mode of expression.

Figure: Types of Applied Stress