Investigation into anti-penetration analytical model of composite sandwich structure with UHMWPE laminate under high speed impact of cylindrical projectile

Objectives In order to quickly evaluate the ballistic performance of an ultra-high molecular weight polyethylene (UHMWPE) composite sandwich structure, a theoretical analysis model of its resistance to high-speed cylindrical projectile penetration is established.

Methods First, the penetration resistance process of the sandwich structure is divided into three stages, the energy dissipation problem in each stage is analyzed, theoretical analysis models are proposed which ignore and consider the upsetting of the cylindrical projectiles respectively, and the equations between the dissipative energy and residual velocities of each stage are built. Next, a numerical model of the projectile resistance of the UHMWPE composite sandwich structure is established using finite element software ANSYS/AUTODYN, and the ballistic limits are obtained by calculating the residual velocities of the projectiles and using the fitting method. Finally, the results of the theoretical analysis models and numerical model are compared.

Results Based on the numerical model results, the ballistic limit errors of both theoretical analysis models are less than 22%, but the ballistic limit of the theoretical analysis model that considers projectile upsetting has higher calculation precision when the maximum errors, mean errors and correlation coefficients are considered together.

Conclusions The proposed theoretical analysis models can be applied to effectively calculate the ballistic limits of UHMWPE composite sandwich structures against the impact of cylindrical projectiles, providing valuable references for the penetration resistance calculation of other fibre composite sandwich structures.