Efficient three-dimensional geometrically nonlinear analysis of variable stiffness composite beams using strong Unified Formulation

The use of composite laminates for advanced structural applications has increased recently, due in part to their ability tailoring material properties meet specific requirements. In this regard, variable stiffness (VS) designs have potential improved performance over constant designs, made possible by fibre placement technologies which permit steering the path achieve in-plane orientation. However, expanded, large design space, computationally expensive routines are required fully explore VS designs. This computational requirement is further complicated when composites deployed involving nonlinear deflections often necessitate complex 3D stress predictions accurately account localised stresses. work, we develop a geometrically strong Unified Formulation (SUF) analysis structures undergoing deflections. A single domain differential quadrature method-based 1D element coupled with serendipity Lagrange-based 2D finite used capture kinematics structure axial and cross-sectional dimensions, respectively. Predictions from SUF compare favourably against those literature as well ABAQUS models, yet also show significant enhanced efficiency. Results deflection demonstrate response variation coupling effects different loading regimes.