Optimization of thermal noise propagation and mechanical properties at composite material interfaces

Abstract

This study investigated the propagation of thermal noise in composite material interfaces and the optimization of mechanical properties, focusing on applications in gravitational wave detection systems. Gravitational wave detection requires extremely high sensitivity, imposing strict demands on the propagation of thermal noise and temperature fluctuations in materials. The study analyzed the multi-interface structure of composite materials and its crucial role in temperature control and thermal noise transport, particularly examining the impact mechanisms of interfacial thermal resistance and conductivity. Through molecular dynamics simulations, the study revealed the regulatory effect of branched structures with varying numbers of monomers on heat conduction paths, demonstrating that thermal conductivity increased from 0.00384 W/(m·K) to 0.01645 W/(m·K), a 3.28-fold improvement. Additionally, the study analyzed the effect of interfacial heat source input on temperature distribution, finding that with a 0.2 W/m² input, the temperature distribution difference was within 35 %, while with a 0.2 GW/m² input, the difference reduced to 20 %. The study also explored the effect of monomer count in branched structures on the mechanical properties of materials, such as Young's modulus and shear modulus. The results indicated that the Young's modulus of the interface in the Z-direction increased by 152.89 % when the monomer count in the branches reached 13. The findings suggest that the rational design of interface structures can significantly optimize the thermal transport and mechanical properties of composite materials.