Research And Application Of Time-frequency Characteristic Analysis Method Of Deep Water Explosion Pressure

In recent years,with the improvement of marine strategic position,the number of marine engineering construction and resource development projects has increased,and there is an urgent need for in-depth study of the mechanism of deep-water explosion and construction technology of deep-water blasting.In deep-water blasting engineering,how to reasonably use underwater explosion energy to effectively destroy targets and minimize the impact of deep-water explosion shock waves and bubble pulsation on hydraulic structures,ships and aquatic organisms has become the research and development of underwater explosions.An important subject for practical blasting engineering applications.At present,there is a lack of research on underwater explosion pressure signals,especially deep water explosion pressure signals.The frequency and energy distribution characteristics of deep water explosion pressure signals need to be explored in depth.Based on the experimental test data of 10 g TNT equivalent deep water explosion container pressurized to simulate the water depth environment,this paper analyzes the explosion pressure signal under different water depth conditions.First,based on the measured signals from the deep-water explosion container,the wavelet transform method is used for signal processing,and two wavelet bases suitable for explosion signals,sym5 and db3,are used for comparative analysis to obtain the time-frequency domain distribution characteristics and energy ratio of the underwater explosion shock wave signal Wait for the situation.However,the analysis results obtained by different wavelet bases are different,reflecting the limitations of wavelet transform,and verifying that the underwater explosion pressure signal is more sensitive to the selection of wavelet bases.Then,the HHT method was used to analyze the time-frequency analysis of the deep-water explosion pressure signal,and the marginal spectrum of the instantaneous energy map of the signal was obtained,and the energy distribution proportion of each frequency band was counted.The analysis results show that the vibration frequency of the deep water explosion pressure signal is roughly within 500 Hz.The HHT method is very suitable for deep-water explosion pressure signal analysis,overcomes the limitation of wavelet function needs to choose basis function,and gives full play to the advantages of high efficiency and high adaptability.Finally,through analysis,it is found that as the depth of water increases,the proportion of bubble pulse energy in the deep water explosion pressure signal gradually decreases,while the proportion of energy in the deep water explosion shock wave signal increases with the increase of water depth.Therefore,for underwater explosions in shallow waters,attention should be paid to the overall damage to the structure caused by bubble pulsation,while the local damage to the structure caused by explosion shock waves in deep waters is more serious.