Internal force calculation of statically determinate truss basic method is divided into: Node law and section method. Node method: take a node is isolated from the body, the use of node equilibrium conditions, solving the rod axial force approach. Section method: use the appropriate section of the truss taken part (at least two nodes) as a research object, the establishment of equilibrium equations, using a balanced condition for solving truss forces approach. The practical application of these two basic methods are generally flexible options, in combination. Truss http://www.bzhangjia.com