Nonlinear 3-D beam/connector finite element with warping for a glulam dome

Abstract

The main objectives of the present study are to incorporate Saint-Venant's torsion solution in the analysis of a glulam dome with ABAQUS to include warping of rectangular beams, and to model the nonlinear beam/decking connectors (nails) of the dome in order to develop an effective finite element model of the glulam dome for investigating its ultimate load capacity. The shear modulus is modified to include warping of the beams. The nonlinear connector is defined through a user-coded FORTRAN subroutine UEL. Results from the thorough testing of these two capabilities are presented.

A convergence study of the solution in the nonlinear analysis of the dome cap with ABAQUS is performed. The effect of variation in parameters such as the nonlinear material law and the stiffness of hinge-connector elements on the dome cap model is examined. A dome cap model with 16 nailed joints for each beam is analyzed. Dome models with nailed joints at truss bracing points (i.e., the end nodes of the truss bracing elements) and with 16 nailed joints for every beam are analyzed. The results of these models are compared with the models with and without truss bracing. Finally, conclusions based on this study and recommendations for future research are presented.