AbstractAn innovative load-bearing sandwich wall panel with glass fiber-reinforced polymer (GFRP) skins and a foam-GFRP web core (GSFW wall panels, where “GS” denotes GFRP skin and “FW” denotes foam-GFRP web core), which was manufactured using a vacuum-assisted resin infusion process, was developed in this paper. An experimental study involving nine specimens was conducted to validate the effectiveness of this panel for increasing the axial strength under edgewise compression loading. The effects of web thickness, web spacing, web height, and skin thickness on axial stiffness, displacement ductility, and energy dissipation were also investigated. The test results demonstrated that axial strength, axial stiffness, displacement ductility, and energy dissipation could be improved by increasing the web thickness, web height, and skin thickness. An analytical model that considers the confinement effect of foam and the local buckling of GFRP skin was proposed to predict the ultimate axial strength of GSFW panels. A comparison of the analytical and experimental results showed that the analytical model accurately predicted the ultimate axial strength of GSFW wall panels under edgewise compression loading. To simulate the low velocity impact by blindings that are rolled by the wind, an impact test was conducted and the residual axial strength of the wall panels after impact was also investigated.
In this paper, a simple conformal load-bearing antenna structure smart skin with a multi-layer sandwich structure composed of carbon/epoxy, glass/epoxy, and a dielectric polymer was designed and fabricated. The mechanical properties of each material in the designed smart skin were obtained from experiments.
Tests and analyses were conducted to study the behavior of the smart skin under compressive loads. The designed smart skin failed due to buckling before compression failure. The stresses of each layer and the first failed layer of the smart skin were predicted using MSC/NASTRAN. The finite element model was verified by comparing the numerical results from geometrical linear/nonlinear analyses with the measured data. The numerically predicted structural behavior of the smart skin agreed well with the experimental data. The results showed that the carbon/epoxy
layer took charge of most of the compressive load, and the first failure occurred in the dielectric layer while the other layers remained safe.
A numerical model was used to obtain design data from the parametric study. The effect of changing the design variables on the buckling and compressive behavior of the smart skin was also investigated. As a result, it was confirmed that the transverse shear moduli of the honeycomb core had a serious impact on the buckling load of the smart skin when the shear deformation was considerable.