17.4 : 压力的应用

Consider a structure consisting of a boom and a rod designed to support a load. The boom and the rod are joined by a pin and supported by brackets and pins.

First, to analyze various stresses acting on the structure, the boom and the rod are detached from the supports, and the free-body diagram is drawn.

Considering the equilibrium equations, the reaction forces acting on the boom and the rod are calculated.

The reactions at point P cause compression in the boom, and the reactions at point R cause tension in the rod.

The forces exerted on pin Q by the boom and the rod can be determined using a force triangle.

The normal stress arising from the axial force on the boom is calculated by dividing the force prevailing at the member by the cross-sectional area of the boom.

The normal stress acting on the rod is similarly determined.