A refined finite element method for bending analysis of laminated plates integrated with piezoelectric fiber-reinforced composite actuators

This research presents a finite element formulation based on four-variable refined plate theory for bending analysis of cross-ply and angle-ply laminated composite plates integrated with a piezoelectric fiber-reinforced composite actuator under electromechanical loading. The four-variable refined plate theory is a simple and efficient higher-order shear deformation theory, which predicts parabolic variation of transverse shear stresses across the plate thickness and satisfies zero traction conditions on the plate free surfaces. The weak form of governing equations is derived using the principle of minimum potential energy, and a 4-node non-conforming rectangular plate element with 8 degrees of freedom per node is introduced for discretizing the domain. Several benchmark problems are solved by the developed MATLAB code and the obtained results are compared with those from exact and other numerical solutions, showing good agreement.

Compressive performance of a foam-filled fiber-reinforced grid beetle elytron plate

The compressive mechanical properties,failure modes and foam filler strengthening mechanism and effect of a short basalt fiber-reinforced epoxy resin composite grid beetle elytron plate with a polyvinyl chloride(PVC)foam-filled core(GBEPfc)are investigated via compression experiments and the finite element method.The results are compared with those of a grid plate(GPfc)with the same wall thickness as the GBEPfc.Additionally,a fully integrated preparation method and process are developed for the GBEPfc,with a material composition that is close to the structure and composition of the organism.Increases of more than 20%in the specific compressive strength and specific energy absorption of the GBEPfcrelative to the GPfcare ascertained.The foam provides a constraining force for the fiber composite structure;consequently,the trabeculae and honeycomb walls of the core transition from a lower-order deformation that easily occurs to a higher-order deformation that occurs less readily.The interaction between the core composite structure and PVC foam is described.The GBEPfcdeveloped in this paper is simple in structure and easy to prepare,and the material composition is close to biological prototypes and materials used in practical engineerings,which lays a foundation for the application of beetle elytron plates.

On the Generalized Thermoelasticity Problem for an Infinite Fibre-Reinforced Thick Plate under Initial Stress

In this paper,the generalized thermoelasticity problem for an infinite fiberreinforced transversely-isotropic thick plate subjected to initial stress is solved.The lower surface of the plate rests on a rigid foundation and temperature while the upper surface is thermally insulated with prescribed surface loading.The normal mode analysis is used to obtain the analytical expressions for the displacements,stresses and temperature distributions.The problem has been solved analytically using the generalized thermoelasticity theory of dual-phase-lags.Effect of phase-lags,reinforcement and initial stress on the field quantities is shown graphically.The results due to the coupled thermoelasticity theory,Lord and Shulman’s theory,and Green and Naghdi’s theory have been derived as limiting cases.The graphs illustrated that the initial stress,the reinforcement and phase-lags have great effects on the distributions of the field quantities.