The effect of different strain quantities on behavior of pin-jointed structural systems

摘要

The possibility of including any slender member into a skeletal structural system, particularly the steel structural system, causes to emerge the stability problem. Furthermore, this possibility also triggers to arise the geometric nonlinearity problem due to an increase in the nodal displacements. Thus, the equilibrium path gains a big importance in order to handle these issues at the same time. However, the variety in the strain measurements leads to a differentiation in the prediction of equilibrium path. At this point, this work lays down the effect of different stain quantities on the equilibrium path. In this regard, a corotational-based truss-type structural element formulation is implemented into the computing mechanism of nonlinear structural analysis approach, named Orthogonal Residual method. The results, which are obtained by the execution of employed structural analysis approach, are compared with not only the outcomes of well-known four benchmark test problems but also OpenSees program, which is coded as an open-source. Consequently, it is shown, (i) the use of different strain quantities causes a significant change on the equilibrium path (ii) the implementation of this practical nonlinear structural analysis approach into OpenSees program provides a big contribution for the further evaluation of equilibrium paths.