Finite-Strip Method for the Analysis of Cracked Plates with Application to Plate-Girder Bridges

Abstract

The finite-strip method (FSM) is one of the most efficient methods for structural analysis of bridges, reducing the time required for analysis without affecting the degree of accuracy. FSM is therefore an ideal platform for traditional time-consuming fracture analysis. This paper presents a new bending crack strip (BCS) that combines the shape functions of the spline finite strip with the eigenfunction solutions of the differential equations that govern the deflection around a crack. When this new BCS is implemented in FSM, complex three-dimensional plate structures with embedded cracks that are perpendicular to the longitudinal axis of the strips can be analyzed efficiently. The stress intensity factors of such structures can be directly computed with BCS. Extra nodal points are used around the cracked area to increase the precision of the numerical method. A substructuring technique is employed to determine the corresponding degrees of freedom of the boundary nodes, resulting in efficient analyses of cracked plates and plate-girder structures. This paper presents two examples to illustrate the accuracy and convergence rate of BCS as well as to demonstrate applications of the proposed model in the analysis of plates and plate girder bridges.