Design of lightweight damping core for composite sandwich structure

Abstract

The damping performance and lightweight design requirements of composite sandwich structure core were studied. A series of low density damping cores were prepared by blending epoxy/polyurethane graft copolymer (E-g-U) and epoxy/poly mercaptan block copolymer (E-b-M) with different contents of hollow glass beads (HGM). The damping properties, mechanical properties, density, and interface morphology of the core layer were studied. The damping response and flexure properties of the sandwich composite structure were studied by modal analysis and three-point flexure test. The experimental results show that optimal damping performance of matrix appears at 60% E-b-M ratio, the peak loss factor is 0.88, and the damping temperature range covers À2 $ 52 C. When the HGM content in the core is 10 phr, the density can be comparable to that of the buoyancy material. Under flexural load, the ultimate shear strength and shear modulus of the sandwich structure increase maximum at 15 phr and 10 phr, respectively. Compared with the unfilled HGM sample, the first three modal damping ratios of the sandwich structure are increased by 133.2%, 56.6%, and 56% by 10 phr damping core, respectively. The results are compared with those in other reference. The research shows that the design of lightweight damping core is expected to provide a core material selection for the vibration reduction of sandwich structures.damping core, damping ratio, flexural properties, low density, sandwich structure | INTRODUCTIONComposite materials have developed from rice straw reinforced clay and reinforced concrete used in ancient times to advanced composite materials nowadays. Their bearing capacity and multi-functional characteristics have been developed incisively and vividly. They have been widely studied and applied in aerospace industry, marine structure design, seismic building construction, and sensor detection. [1][2][3][4][5][6] In the face of complex and harsh environment, the theoretical research on the dynamic performance and dynamic stability of composite materials under dynamic load is becoming more and more in-depth. [7][8][9][10] Due to many complex external loads, the composite structure will produce large vibration and noise problems, which will bring security risks such as performance stability to the structure and equipment. This is why the sandwich structure has become the focus of attention due to its high specific strength, sound absorption, vibration reduction, large stiffness, lightweight, and other obvious characteristics. [11][12][13]

Dynamic responses and damage evolution of conformal radome composites under blast loading

“…Many sandwich structures with various cores were proposed for the application of blast resistance. Meanwhile, the sandwich composites exhibit good lightweight performance 20–24 . Among the sandwich structures, the woven lattice sandwich composite (WLSC) made of fiber yarns has outstanding advantages in the EM functions, 25,26 due to the construction of discrete core piles.…”

“…Meanwhile, the sandwich composites exhibit good lightweight performance. [20][21][22][23][24] Among the sandwich structures, the woven lattice sandwich composite (WLSC) made of fiber yarns has outstanding advantages in the EM functions, 25,26 due to the construction of discrete core piles. Moreover, the integrated faces and cores make WLSC exhibit superior delamination resistance.…”

Experimental study of the ballistic resistance of micro‐bead modified epoxy resin filled S‐shaped folded sandwich panels

“…[ 23 ] The hollow glass bead (hereafter referred to as HGB) is a desirable filler. [ 24 ] Because the HGB has excellent physical and chemical properties such as high compressive strength, small specific surface area, smooth and rounded external shape, and good dispersion in the resin. The micro‐beads‐modified resin (referred to as modified resin) is obtained by modifying the epoxy resin with a small amount of HGB, [ 25,26 ] and the modified resin can improve the fracture behavior while reducing the density.…”