Thermo-Mechanical Instability Characteristics of Laminated Composite Cylindrical Shells

摘要

Even with small infinitesimal increase in load, change of equilibrium configuration of completely different character is highly possible for thin shell structures and that could eventually result the whole structure become unstable. This article presents numerical investigation on buckling and post-buckling characteristics of laminated composite circular cylindrical/conical shell subjected to torsional, thermal and combined loads. Using commercial finite element software ABAQUS, both linear and nonlinear buckling response of composite shells are simulated. Linear critical buckling load due to uncoupled torsional and thermal loads is determined using eigen value buckling analysis. Non-linear post-buckling response of shell is simulated using Riles arc length method. Un-coupled and coupled influence of thermal-torsional influence to critical buckling load is estimated. Mode shape associated with linear Eigen value analysis are used as initial geometric imperfection for non-linear analysis. Thermo-mechanical coupling found reduces the buckling load resistance of cylindrical shell by maximum of 47%. It was observed that the generation of additional axial compressive reaction force due to thermal expansion restrain on axial constrained shell edges could be the major influential factor. Except a small radial expansion of cylindrical surface, deformation shape predicted from non-linear post buckling analysis resembles rather similar irrespective of any proportion of thermal-torsional coupling.