Abstract
The main objective of this study is to develop a macro-model finite element code, which can simulate dynamic behaviors with strong nonlinearities and discontinuities and is efficiently applicable to seismic collapse analyses of framed structures. The applied technique is called the ASI-Gauss technique for the linear Timoshenko beam element, which computes highly accurate elasto-plastic solutions even with the minimum number of elements per member. It gains high accuracy especially in elastic range, by placing the numerical integration points of the two consecutive elements forming an elastically deformed member in such a way that stresses and strains are evaluated at the Gaussian integration points of the two-element member. Moreover, the technique can be used to express member fracture, by shifting the numerical integration point to an appropriate position and by releasing the resultant forces in the element simultaneously. The numerical code can be used to analyze dynamic behaviors of framed structures, initiating from elastic range to a total collapse. Simple numerical tests are conducted in this paper to verify the proposed code. Moreover, a three-dimensional seismic collapse analysis considering member fracture and contact is performed on a large-scale framed structure, and practical results are obtained in a reasonable short calculation time.