Final answer:
The 3 main superimposed loads to be aware of are compressive stress, tensile stress, and shear stress, all of which are crucial for ensuring structural stability in engineering applications.
Step-by-step explanation:
The 3 main superimposed loads to be aware of are compressive stress, tensile stress, and shear stress. Compressive stress occurs when a material is subjected to forces that tend to squeeze it, such as a shelf carrying the mass of heavy books. Tensile stress is the opposite, where a material is subjected to forces that tend to stretch it, which might be evidenced when a long beam sags under its own weight. Finally, shear stress occurs when forces act parallel to the surface of a material, for example, when scissors cut through paper, creating a shearing action.
Understanding these loads is essential for structural stability and integrity, particularly in construction and engineering applications. For instance, superimposed loads need careful calculation to ensure the stability of bridge cabling, as the horizontal components of the tensions must cancel out and the vertical components must balance the weight of the bridge traffic or suspended objects like lights.