A Constraint Matrix Approach for Structural Ultimate Resistance to Access the Importance Coefficient Values of Rigid Joints

Abstract

This paper focuses on the importance coefficients of component ends and rigid joints in structural robustness evaluation. The importance coefficient relies on the change of structural bearing capacity after a certain component end or rigid joint changes to a hinge. From conception, the components stiffness, strength and connection type, the structural topological relation, and the conventional load effects are all synthetically considered. From algorithm, based on the constraint matrix which describes the rotation constraint moments of the component ends to the whole structure, a simplified method for calculating the structure ultimate resistance is put forward. The new method avoids the rearrangement and inversion of the structural stiffness matrix and it is especially suitable to complex rigid frame structures. Some comparisons between the new method and the matrix displacement method are given, and the results show that the proposed method is effective and reliable. In addition, the importance coefficients of component ends and rigid joints show that they can play a crucial role in structural robustness estimation.