Theoretical Prediction and Experimental Validity of Thermal Frequency Responses of Laminated Advanced Fiber-Reinforced Epoxy Hybrid Composite Panel

Abstract

Thermal frequency responses of the hybrid laminated composite panel are theoretically computed using the finite element model and for the first time compared with in-house experimental data. The structural model for hybrid panel is derived using higher-order displacement polynomial functions (to maintain the necessary stress/strain continuity) and discretized through the isoparametric finite elements. Moreover, the elastic properties of the composite are evaluated suitably including thermal and physical parameters of the advanced fibers (Glass/Carbon/Kevlar) with the help of experimentations and numerical tool (via ABAQUS using mean-field homogenization). The variation of modal responses due to the change in temperature increment is computed through a generic computer code generated via the higher-order mathematical model. The numerical frequency values are compared with the earlier published numerical results and the experimentally recorded eigen frequencies. The experimental verifications related to the end boundaries indicate that the incorporation of the clamped boundary for one edge doubles the frequency, whereas the fraction of Kevlar fiber does not influence the stiffness (due to longitudinal modulus) parameter irrespective of the temperature change. Further, the conclusive understandings of the hybrid composite structural panel due to the inclusion of different advanced fibers and other design parameters (geometry, boundary and temperature) are deliberated in detail.