ABSTRACT
In this chapter, a more practical three-dimensional structural analysis using finite elements with degenerated degree of freedom is presented for structures whose internal stress states can be reduced to one-or two-dimensions. For shell structures, the developed stresses are primarily two-dimensional since normal stresses working in the thickness direction can be neglected in most cases. For frame structural members, the developed stress states are mainly one-dimensional along the member axis and other stress components can be neglected without loss of accuracy. This chapter shows how full three-dimensional modeling of materials and structures presented in Chapter 3 can be simplified in order to achieve greater computational efficiency and reasonable accuracy for particular cases. It is clear that the reduced three-dimensional analysis cannot cover all types of structures. Engineers should select the full three-dimensional or the reduced one by considering the applicability and overall computational costs. It is believed that the computational time and difficulty involved in full three-dimensional modeling with the most versatility will be steadily reduced in the near future.
