Thick-walled composite beam theory including 3-D elastic effects and torsional warping

A composite box beam model is developed for both thin-and thick-walled composite beams. In this analysis primary and secondary torsional warping and transverse shear effects, both of the cross-section and of the beam walls, are considered. An efficient method to account for 3-dimensional elastic effects in laminated beam walls is developed. These non-classical effects are investigated and are shown to be accentuated as the wall thickness increases. The present theory is validated by comparison with available experimental data, other analytical results, and finite element analysis. Good correlation between the present theory and other results is achieved for all test cases with predictions within 10% of experimental data for thin-walled beams and 8% of 3-D FEA results for thick-walled cases.