According to the features of the sources of pyroshock and ballistic shock, this study considers the pyroshock and ballistic shock generated by their respective impulsive sources as damped harmonic waves with different frequencies. According to the linear superposition assumption of damped harmonic waves in a linear elastic structure, a shock analysis method based on low-pass-filtered shock signals and their corresponding shock response spectrum (SRS), termed as low-pass-filter-based shock response spectrum (LPSRS), is proposed. LPSRS contains rich information of the frequency distribution of the shock excitation signal. A method to calculate shock transmissibility is proposed based on LPSRS and basic modal information of the equipment structure. LPSRS and SRS curves can be predicted at any given position of the equipment structure. The prediction method is validated by finite element method (FEM) simulation.

A shock waveform is proposed based on the mechanical mechanism of shock generation in a structure. The parameters in the shock waveform have clear mechanical meanings about the generation and development of the shock. A shock signal processing method is proposed and applied to represent a pyroshock or ballistic shock signal in both temporal and frequency domain using finite terms of the shock waveform components. It is found that complexity and dominant shock distance of a shock can be described quantitatively by the number of waveform components (η 90% ) and a normalised parameter (κ), respectively. Pyroshock and mechanical shocks in different categories are analysed using the proposed shock waveform to demonstrate its importance and generality in shock representation.

Shock response spectrum (SRS) is a widely accepted method for shock testing specification. However, SRS, as a supremum, is over-conservative and cannot fully describe the relative severity for various shock environments. This study introduces shock response matrix, from which shock severity infimum (SSI) can be extracted using singular value decomposition method. Based on SRS and SSI, dual spectra are introduced to determine the range of shock severity between its supremum and infimum. The evaluation of the relative severity of various shock signals is discussed and validated by finite-element simulations.

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