Ultimate strength characteristics and assessment of laser-welded web-core sandwich plates under combined biaxial compression and lateral pressure

Abstract

The ultimate strength and the collapse characteristics of laser-welded web-core sandwich plates subjected to the combined biaxial compression and lateral pressure are investigated by the finite element method. The finite T-joint rotation stiffness is considered, which is derived from the published experimental data. The results show that the finite T-joint rotation stiffness will result in a maximum of 23% decrease in the transverse ultimate strength, much larger than that in the longitudinal ultimate strength. The decrease of the transverse shear stiffness accounts for the reduction of the load-carrying capacity. The lateral pressure reduces the ultimate strength of the sandwich plates, and the reduction in the ultimate strength dominated by the longitudinal compressive collapse is more significant than that in the ultimate strength dominated by the transverse compressive collapse. The applied compressive stress ratios determine the collapse modes of the sandwich plates, which explains the difference in the degree to which the lateral pressure reduces the ultimate strength under the biaxial compression. Based on the numerical results, a preliminary formula is proposed in this paper to assess the load-carrying capacity of the laser-welded web-core sandwich plate subjected to the combined biaxial compression and lateral pressure.