Nonlinear transient analysis of delaminated curved composite structure under blast/pulse load

Abstract

The nonlinear time-dependent displacement values of the curved (single/doubly) composite debonded shell structure are examined under different kinds of pulse loading in this research. The structural curved panel model is derived mathematically using the higher-order displacement theories containing the thickness stretching effect, whereas the sub-laminate approach is adopted for the inclusion of delamination between the subsequent layers. The structural geometry distortion under variable loading has been included in the current theoretical analysis through Green–Lagrange type of strain kinematics. Further, the governing differential equation order has been reduced with the help of 2D finite element formulation via the nine-noded isoparametric Lagrangian elements with variable degrees of freedom (eighty-one and ninety) for two different higher-order kinematics, respectively. The final equation of motion is solved computationally to evaluate the transient responses through an original computer code including the direct iterative technique and Newmark’s average acceleration method. The convergence criteria of the current numerical solution are established as a priori and the subsequent validity is demonstrated via comparing the current responses with available published data. Further, the comprehensive behavior of the debonded structure under the influence of the variable loads (time and area dependent) is evaluated by solving different numerical illustrations for variable geometrical configuration and described in detail.