Dynamic Analysis for Delaminated Composites Using DKQ Concept Based on Higher-Order Zig-Zag Theory

Abstract

* Associate Professor, AIAA member † Graduate Research Assistant ‡ Graduate Research Assistant ABSTRCT A finite element based on the efficient higher order zig-zag theory with multiple delaminations is developed to refine the predictions of frequency and mode shapes. Displacement fields through the thickness are constructed by superimposing linear zig-zag field to the smooth globally cubic varying field. The layerdependent degrees of freedom of displacement fields are expressed in terms of reference primary degrees of freedom by applying interface continuity conditions as well as bounding surface conditions of transverse shear stresses including delaminated interfaces. Thus the proposed theory is not only accurate but also efficient. This displacement field can systematically handle the number, shape, size, and locations of delaminations. Throught the dynamic version of variational approach, the dynamic equilibrium equations and variationally consistent boundary conditions are obtained. Through the natural frequency analysis and time response analysis of composite plate with delaminations, the accuracy and efficiency of the present finite element are demonstrated. The present finite element is suitable in the predictions of the dynamic response of the thick composite plate with multiple delaminations.