MEC E563 Lecture Notes - Lecture 2: Direct Stiffness Method, Gusset, Structural Mechanics

• School: University of Alberta
• Department: Mechanical Engineering
• Course: MEC E563
• Professor: Walied Moussa

Document Summary

This chapter begins the exposition of the direct stiffness method (dsm) of structural analysis. The dsm is by far the most common implementation of the finite element method (fem). In particular, all major commercial fem codes are based on the dsm. The exposition is done by following the dsm steps applied to a simple plane truss structure. The method has two major stages: breakdown, and assembly+solution. The simplest structural nite element is the two-node bar (also called linear spring) element, which is illustrated in figure 2. 1(a). A six-node triangle that models thin plates, shown in figure 2. 1(b) displays intermediate complexity. Perhaps the most geometrically complex nite element (at least as regards number of degrees of freedom) is the curved, three-dimensional, 64-node brick element depicted in figure 2. 1(c). Yet the remarkable fact is that, in the dsm, all elements, regardless of complexity, are treated alike!