Experimental and analytical studies on bearing capacity of bolt connected composite plate girders

Abstract

Composite plate girders bearing the enormous concentrated loads from boilers are common members in thermal power plants. Because of their large scale and sustaining distinct loads, the section of these girders is made of two parts combined with high strength bolts. Experimental investigations on two I-section plate girders, two homogeneous composite girders, and two hybrid composite girders, are implemented. Bearing capacity and member ductility are compared among the three kinds of specimens. To reveal the mechanism of composite plate girders, force method built upon the linear elastic theory is employed, according to deformation coordination among the components. The elastic stress distribution predicted by the analytical method is validated against test data. Based on the internal force distribution derived, the elastic effective width method in current specifications and the plastic effective width method proposed in other published literature are employed herein to predict the critical load. Conclusions can be made that bearing capacity of composite girders is superior to the I-section ones, and hybrid composite plate girders can further balance the economic and mechanical efficiency of constructions. Additionally, several proposals for application are offered.