Nonlinear analysis of elastic high-shear deformable plane frames by a mixed FEM path-following approach

This paper deals with the nonlinear analysis of high-shear deformable elastic plane frame, frequently used to model beam of composite materials, elastomeric beam-like bearings of bridge and seismic isolation, or to model DNA strands and polymer chains. The work uses a FEM approach based on a Cosserat–Timoshenko beam model with an exact geometrical description, evaluating all the axial, shear and bending contributions. It follows a mixed implementation of a Riks-path following locking-free strategy of analysis, exploring its implementation details and proving its effectiveness and reliability. At last the paper reports the quantitative and qualitative influence of shear contribution on known classical examples.