Abstract and subjects
Shock Response Spectra (SRS) are commonly used in dynamic testing to describe the mechanical environment in high-energy, non-stationary events, such as impacts or pyrotechnic shocks. Oftentimes, the service environment to which a structure will be exposed is difficult to reproduce in the laboratory, but design engineers desire a laboratory screening test to determine whether the structure will survive an anticipated shock environment. Herein, a combined experimental and numerical study is pursued to evaluate the efficacy of different methods to elicit failure modes of a service shock through destructive shaker tests of a custom-designed test article fabricated using commercially available 3-D printers. Design of the test article is explored through use of finite element modeling, which is found to correlate well to experimentally-obtained natural frequencies. Four techniques to synthesize a service shock are compared: least favorable response, sum of decaying sinusoids, wavelet, and matching temporal moments. Destructive shaker tests of the shock responses are performed using 25 nominally identical test articles to assess the ability of each method to impose similar damage states as those obtained when using the service shock. We find that the method of matching temporal moments best replicates failure modes of the service shock; however, further testing is needed to validate our observations.