Dynamic structural response of thin conical shells during drop impact and related load characteristics

To study the deformation and failure modes of thin conical shells during drop impact and related load characteristics derived from the structural response of conical shells, the dynamic structural response of thin conical shells during drop impact and related load characteristics are investigated in the present manuscript, integrated with the numerical simulation and the stress wave analysis. The deformation and failure morphologies of thin conical shells, as well as the acceleration history of components mounted on its upper end will be emphasized, and the influences of several factors, including drop height, structural mass, and support frame rigidity, etc., are also discussed in detail. Related results demonstrate that in the drop impact condition, damage and failure in the thin conical shell mainly initiates in the region near the inner surface at its bottom end, then the whole bottom part separates from the shell, and cracks propagate gradually along with the drop progress, finally petal-like fragments are formed and they further fold inward progressively. The deformation and failure process of thin conical shell significantly affects the acceleration characteristics of components mounted on the upper end. The reflection and superposition of impact stress wave within the conical shell, support frame, and component structure dominate the overall load characteristics. The drop height and structural mass contribute significantly to the deformation and failure morphologies of conical shell and then the acceleration history of the key component, higher drop height will result in higher degree of deformation and longer deformation duration, and then lead to the increase in the amplitude and width of the acceleration pulse; similarly, larger structural mass will also induce higher width of acceleration pulse, but it results in a reduced acceleration amplitude. Moreover, due to the vibration of the support frame during the drop process, a certain vibration feature occurs in the acceleration curve of the key component, and the vibration frequency is the same as the elastic vibration frequency of support frame structure. Related work is beneficial in providing theoretical guidance for the structural design of load generators based on thin conical shells.