Simulation method of debris cloud from fiber-reinforced composite shield under hypervelocity impact

A Whipple shield is a double-plate structure commonly used to protect spacecraft from space fragments. The space fragments hit the outer plate and break into a debris cloud with dispersed energy and momentum, which reduces their risk of penetrating the bulkhead. With the development of high-performance materials, for example, high-performance fiber composites, traditional Whipple shields have evolved into advanced complex shields. Using the finite element and smoothed-particle hydrodynamics adaptive method and mesoscopic modeling technology, this study aims to establish a numerical model for fiber-reinforced composite shields under hypervelocity impact. Several mesoscale models for fiber-reinforced composites for problems under hypervelocity impact have been established. These models can be meshed with high-quality elements that satisfy aerospace engineering requirements (identify hazardous fragments in the debris cloud) while retaining the main structural features of materials. We established a numerical model by combining the finite element and smoothed-particle hydrodynamics adaptive method and existent mesoscale models. Using laminates, 2D woven fiber-reinforced plastics, and 3D woven fiber-reinforced composites as examples, numerical simulations of the debris cloud generated by an aluminum ball under hypervelocity impact were conducted. The simulation results, which are highly consistent with the experimental results of the debris cloud shape, accurately reflect the failure features of laminates, that is, fiber fracture and delamination. Simulation results show that the fiber-reinforced composite has better protection than the aluminum plate at the same areal density. By comparing the debris clouds generated by the hypervelocity impact on different fiber-reinforced composite shields, it can be argued that composite knit modes strongly affect the protective effect of fiber-reinforced composites. This work shows that the simulation method combining the finite element and smoothed-particle hydrodynamics adaptive method and mesoscopic modeling is a powerful tool for simulating the Whipple shield with a fiber-reinforced composite. More importantly, this method can also be applied to other Whipple shields with complex structures and advanced materials, for example, other composite materials, metal foam materials, and multilayer board protective structures.