Improved extended high order analysis of sandwich beams with a bilinear core shear behavior

Abstract

The response of a sandwich panel with bilinear constitutive behavior for shear stress of a core is presented based on a proposed improved extended high order sandwich panel theory. In this theory the face sheets are analyzed based on the first order shear deformation theory that is hitherto not applied in the conventional extended high order sandwich panel theory. Besides, the two-dimensional (2D) elasticity is used for the core. The field equations are derived using the Ritz-based solution which is suitable for any essential boundary condition. In each type of boundary conditions, the effects of plastic shear modulus of the core on transverse shear stress distribution within the core, transverse normal stresses at top and bottom face sheet–core interfaces, displacement components through the thickness of the core, as well as the force and moment resultants and transverse displacements in the face sheets are studied in detail. Also, all results based on the bilinear material assumption of the core are compared with the linear elastic ones. The results reveal that initial plastic regions are created at core edges. Furthermore, the absolute value of shear stresses in the plastic zones based on the bilinear analysis is lower than those obtained from linear elastic one for both types of the boundary conditions. It is seen that, unlike the case of the clamped edges, the plastic regions predicted by bilinear material behavior are much more extensive than ones resulted from elastic material behavior in the simply supported case. Finally, in the case of the linear elastic analysis, the results of the transverse deflections and shear stresses are compared with finite element simulation.

A new nonlinear model for studying a sandwich panel with thin composite faces and elastic–plastic core

“…3 and 4 respectively. The value of the shear stress for various bilinear ratio are in good agreement with results off [20], but the trend of the shear stress is slightly different. This difference is due to the difference of the solution procedure.…”

“…They employed the Ritz based solution procedure to extract the results. The geometrical and mechanical properties of the panel are presented in Table (1). The results of [20] and the results of present study are shown in Figs. 3 and 4 respectively.…”

“…To ensure the validity of the solution, the results of simply supported case are compared with the results of extended high order analysis presented by Salami et al [20]. They employed the Ritz based solution procedure to extract the results.…”

“…Swanson [19] examined high order theory for some sandwich plate problems and mentioned the importance of stress concentration in the face sheets and the core revealed from this theory. Jedari Salami et al [20]studied response of a sandwich panel with bilinear constitutive behavior for shear stress of a core based on the improved extended high order sandwich panel theory. In this theory the face sheets are analyzed based on the first order shear deformation theory that hitherto is not applied in the conventional extended high order sandwich panel theory.…”

Failure mode prediction for composite structural insulated panels with MgO board facings

“…Growing popularity of sandwich structures led to numerical implementation of shell theory formulations appropriate for these kinds of structures [29][30][31][32][33][34][35]. However, since the FEM model has to be able to predict localised failure modes, core was modelled with solid elements, based on similar research [5][6][7][8][9][10][11][22][23][24].…”