Sandwich-structured composite

About: Sandwich-structured composite is a research topic. Over the lifetime, 5853 publications have been published within this topic receiving 101126 citations.

Improved sandwich structured ceramic matrix composites with excellent thermal insulation

Abstract: An improved sandwich structured composite with low thermal conductivity used in high temperature is discussed, which have a great potential to be used in thermal protection system. This composite was composed of compound core material and C/SiC laminates. It is crucially noted that the compound core material is composed of reticulated SiC foam and SiO 2 powders. In this paper, the thermal conductivity of compound core was much lower than that of unfilled SiC foam in high temperature. It was also observed that the thermal conductivities of compound cores with the density ranged from 1.23 to 1.38 g/cm 3 increased accordingly. A mathematical relation was derived to calculate the theoretical effective thermal conductivity of sandwich structured composite, and the results agreed with the measured data with an error of 5%.

Method for forming a composite structure

Abstract: A method of forming a three-dimensional composite structure. Uncured portions of the composite structure are first assembled between a initially rigid heat-softening inner layer of ABS plastic and a hard outer mold surface. Prior to curing of the composite structure, pressure and heat is applied to the ABS layer to soften the layer. Thereafter, pressure is applied to the side of the ABS layer opposite from the composite structure, thereby to compact the uncured portions of the composite structure against the hard outer mold. Stiffening beams may be incorporated into the composite structure, so as to yield a lightweight, strong composite structure that can be used as a pressure vessel in an aerospace vehicle.

Free-Edge Effects in the Characterization of Composite Materials

Abstract: In the use of flat specimens for the characterization of composite materials, stress free edges often are encountered. In the case of laminated tension specimens, such free edges induce interlaminar stresses which can disturb the desired state of stress. Large stress concentrations can be induced by free edges, such as in the rail shear test. Other examples include the sandwich beam test. A general review of free-edge problems as related to composite characterization is presented, including a discussion of narrow versus wide specimens. Particular attention is given to the sandwich beam test where a preliminary analysis of the free-edge problem reveals a state of stress which differs from a tensile coupon.

Experimental and Numerical Analysis of Critical Buckling Load of Honeycomb Sandwich Panels

Abstract: The critical buckling loads for various core densities and materials of honeycomb composite panels are experimentally and numerically investigated in this study. The surface plates of honeycomb composite panels are of polyester/glass fiber composite. Polyester resin-impregnated paper or aluminum is used as the honeycomb core material. Honeycomb panels with different cell sizes, but approximately the same volume, are produced and the effect of the honeycomb core density on the critical buckling load is investigated by compression tests. The critical buckling load of paper core panels is determined to be higher than that of aluminum core panels. It is seen that the buckling strength of the specimens increases by the increase of core density. As the critical buckling load exceeds a certain limit, regional core cell buckling and core crushing are seen in aluminum core panels. In paper core panels, regional cracks are seen, in addition to these failures. The study also calculates the numeric buckling loads of the panels using the ANSYS finite element analysis program. The achieved experimental and numerical results are compared with each other and the results are provided in tables.