Numerical Study on the Dynamic Behavior of Layered Structures under High-Velocity Impact

Spallation occurs when materials exceed their tensile limits under extreme loading conditions, such as high-velocity impacts and shock loading. It is characterized by dynamic void nucleation and fracture growth as tensional waves propagate. Understanding and managing spallation are crucial for maintaining material integrity in extreme circumstances. This study employs numerical methods to investigate spallation and internal pressure in layered structures, which represent the most simplified version of composites. The focus is on understanding the underlying mechanisms and effects of spallation. As the number of layers increases to mimic realistic materials like laminates, the results exhibit behavior similar to that of homogeneous materials, which has significant implications. It is also noteworthy that some layer models of the shock profile, known as the pull-back signal, do not manifest despite the occurrence of internal fractures. This observation suggests that the existing spallation studies on multilayered structures, which rely solely on the shock profile's pull-back signal, may lead to errors in calculating spall strength for composite and layered materials.