ABSTRACT
This chapter describes how to combine bending, shear, axial, and torsional stiffnesses to form the element stiffness matrices for bridge columns and cap beams. The bending stiffness matrices of column and cap beams are presented in Chapter 4 and based on the hysteresis models described in Chapter 3. The stiffness matrix formulation for other elements such as brace and plate elements are introduced in this chapter. Once all the element stiffness matrices are formulated, a 3D structural system subjected to both static and nonlinear pushover loadings can be analyzed. To perform static and nonlinear pushover analyses, the structural joints and degrees of freedom (dofs) need to be de•ned •rst; a process is described below.
