ABSTRACT
This chapter discusses the theoretical basis, capabilities, and limitations of the finite element techniques for the nonlinear stress analysis of metallic and reinforced concrete structures as successfully implemented in DENA. The finite element method appeared as a numerical technique for the analysis of boundary value problems in the mid 1950s.In the finite element analysis of concrete structures two distinct cracking models, i.e. discrete and smeared, have been developed to date. A full description of smeared cracking models requires the treatment of a cracking criterion, strain softening, and a shear transfer model. In the post cracking stage the notions of strain softening or tension stiffening is used depending on whether the element is plane concrete or reinforced concrete respectively. Although both criteria may be used, experience has shown that the second criterion is more appropriate especially in analysis of reinforced concrete structures. A new algorithm for embedding reinforcement of arbitrary shape in concrete elements is developed.
