Synthesis of gunfire shock signals with controllable SRS and temporal features: SRS-based synthesis of gunfire shock signals with temporal features

Aircraft-mounted weapons systems generate intense shock and vibration during combat missions, creating a highly complex, repetitive, and nonstationary environment. Avionic devices and components are susceptible to damage in severe gunfire shock environments and must undergo shock testing. In the absence of measured data, gunfire shock signals synthesized from Shock Response Spectrum (SRS) should serve as input excitation. However, the synthesis of gunfire shock signals presents several challenges, primarily due to the transient and repetitive nature of gunfire shock itself, as well as the inherent non-linearity in the SRS method. This paper presents a novel method for synthesizing gunfire shock signals that match SRS specifications while maintaining realistic temporal characteristics. The proposed method utilizes a shock-waveform dictionary technique to generate single-shot shock signals with controllable features including initial rise time, effective duration, and repetition intervals. These single-shot signals are then duplicated and concatenated to create multi-shot sequences, with low-frequency compensation applied to meet SRS requirements. The method's effectiveness is demonstrated through a case study simulating the M61A1 aircraft cannon firing at 4 000 rounds per minute, achieving an average error of only 0.35 dB compared to SRS specifications. Further validation across two additional cases with varied single-shot durations and repetition intervals underscores the method's generalizability. The proposed synthesis method provides a practical solution for laboratory testing of avionic equipment under gunfire shock conditions when measured data is unavailable.