Monolithic and Staggered Strategies Using Solid-Shell Formulations for Nonlinear Coupled Thermoelasticity

In this work, monolithic and staggered schemes using a locking-free solid-shell element are proposed to analyze the behavior of thin-walled structural components subjected to combined thermal and mechanical loads. The enhanced assumed strain method, assumed natural strain method, and reduced integration with hourglass control are incorporated into the formulation of the eight-node solid-shell element to seek accurate predictions of the structural response of the elastodynamic systems. The thermal field (the solution of the heat conduction problem) is obtained using a standard eight-node solid-element formulation with full integration. Element formulations for monolithic, isothermal, and isentropic staggered schemes are presented. The use of different element formulations in the structural and thermal fields brings difficulties in implementing the isentropic scheme; hence, special efforts are made to preserve its convergence properties and numerical stability. Numerical examples demonstrate the accuracy and efficiency of the present locking-free solid-shell element in conducting large-deformation thermoelastic analyses of thin-walled structures. In particular, the isentropic scheme with only a one-pass strategy presents equal robustness but superior efficiency to the monolithic element in simulations considering weak, as well as strong, couplings. (C) 2019 American Society of Civil Engineers.