-

In order to carry out a nonlinear structural analysis, the actual behavior of members in nonlinear range of deformations must be known and considered. In this type of analysis, the said behavior must be in conformity with experimental observations. In the structures with tubular members such as
jacket type offshore structures, two types of
member behavior i.e. strut and portal may be observed. In this paper a nonlinear fiber element (Post buckling Beam Column
Fiber Element) for the simulation of
nonlinear responses of tubular members is formulated. This element is implemented in the non-linear program DRAIN-3DX. The results of this element are compared with available experimental and analytical models. They show satisfactory result for both strut and portal members.