A COMPOSITE BEAM FINITE-ELEMENT MODEL WITH P-VERSION ASSUMED WARPING DISPLACEMENT

A finite element model that can accurately represent the warping of composite beams is presented. A p-version formulation for the assumed warping displacement is used, with warping displacements, and higher-order derivatives as nodal degrees of freedom over the cross-section. The arbitrary warping is then superposed over the deformed cross-section. The p-version formulation allows higher-order approximations of warping and solutions of increased accuracy, without mesh refinement. A consistent formulation for the incorporation of induced strain effects in composite beams is also included in the model. The model can be used for thin- to moderately thick-walled beams, with complicated cross-sections, planforms, taper and pretwist. Transverse shear deformations are included. Numerical tests are presented for single-cell, two-cell and open sections, subjected to axial, bending and torsional loads, and temperature changes. The results show excellent agreement with three-dimensional solid element solutions.