Higher order composite beam theory built on Saint-Venant’s solution. Part-II: Built-in effects influence on the behavior of end-loaded cantilever beams

The higher order composite beam theory (HOCBT), established in Part-I, is a refinement of the one-dimensional beam-like theory related to 3D Saint-Venant’s solution. HOCBT is based on a displacement model including in/out-of plane warpings and is devoted to symmetric and orthotropic composite beams. In the present Part-II, HOCBT is applied to analyze the built-in effects influence on the structural behavior of end-loaded cantilever beams (torsion, tension and shear-bending). In the critical region, close to the built-in section, the 3D (axial and shear) stresses calculated by the proposed theory are relevant and quite comparable to those obtained by 3D-FEM computations. These results, obtained for a representative set of cross-sections, show that HOCBT is able to describe the built-in effects, and hence their influence on the structural behavior of the beam. As expected, moving from the built-in section, the results (displacements and stresses) tend towards Saint-Venant’s solution in the interior part of the beam. It is shown that the extents of the built-in effects are related to dimensionless constants that take into account the whole nature of the composite section and the loading case. Practically, regarding to Saint-Venant results, these constants allow to predict the built-in effects expansion.