Flexural Stiffness of Rectangular Hollow Section (RHS) Trusses

Abstract

The deflection of the rectangular hollow section (RHS) truss in elastic stage can be divided into two parts: the deformation of the members and the joints. The effect of joint deformation on the overall deflection of the truss remains unclear. A new approach for the prediction of flexural stiffness of RHS truss was developed based on pin-jointed analysis. The chords and the braces of the truss were connected by the springs. The flexural stiffness of the RHS truss can be calculated after the stiffness of the springs was obtained. The approach took the axial stiffness of the truss joints as equal to the stiffness of the springs. Then the calculation of axial stiffness of the RHS K joint was proposed to employ the component method. Finally, the proposed approach was verified by the truss test and finite element (FE) results. The approach was also compared to other two existing approaches. The results showed that the proposed approach had the best accuracy in the prediction of the flexural stiffness of the RHS trusses. The maximum relative error of flexural stiffness against the FE results were always within the range of ±25%. The approach reasonably takes the joint deformation into account. The approach also has the potential to achieve high accuracy with different truss types and loading modes.