Impact dynamic response of low damped structures subjected to impulse base accelerations

Shocks and impact loads are generated during the operational life of aerospace vehicles and their effects should be considered for the structural design and verification of these systems. Due to the complexity of assessing shock loads numerically, there is a lack of accurate methods to calculate the mechanical response under a shock environment. One of the existing approaches is the Response Spectrum Analysis, which directly estimates the maximum peak values of structural response accelerations generated by shocks, where it is necessary to define the input acceleration as a Shock Response Spectrum. This approach is based on the calculation of the modal contributions to the total maximum response, which can be combined in different ways, leading to a great variety of possible results for the same response. Furthermore, the existing options generally provide inaccurate results. The objective of this paper is the development and verification of a new method for the Response Spectrum Analysis approach to calculate accurately the peak response accelerations of undamped and low damped structures subjected to impulse base excitations characterized by a main pulse. The proposed method is verified in this paper by numerical analyses for a beam structure to demonstrate the improvement in the accuracy of the provided results compared to the existing options.