Studies On Key Techniques Of Test For Shockwave Overpressure Fields

The purpose of this paper is to obtain the shock wave parameters and the distribution of shock wave field of explosives,guns and other weapons,so as to provide quantitative and reliable data for evaluating damage,evaluating weapons and protecting human ears from exposure to weapons' shock waves.With the design of many powerful new suppressive weapons,the test of shock wave field is faced with many challenges: the construction of test system in large area and the placement of more test points;real-time monitoring of multi-channel data;dynamic calibration,evaluation and compensation of multi-range sensor;detection and extraction of shock wave signal under strong interference noise;modeling of shock wave field under sparse data,etc.In this paper,the above problems have been studied in depth,and some achievements have been achieved.The main contents are as follows:(1)Dynamic calibration of sensors.In this paper,an identification method based on augmented least square algorithm is proposed to establish a high-order dynamic mathematical model for the sensor,and a zero-pole compensation method is used to widen the working frequency band of the sensor.The serious distortion of the shock wave test signal caused by the lack of frequency response of the pressure sensor is corrected.Furthermore,the principle of dynamic compensation based on the fireworks algorithm is put forward,and the moderate function is improved,thus the calibration accuracy is improved.Compared with the dynamic compensation effect based on particle swarm optimization algorithm,the feasibility and effectiveness of the algorithm are verified.(2)Shock wave signal detection.In this paper,an extraction model based on high order spectral power law detection and dual-tree complex wavelet transform is proposed.By using the high order spectral power law detector,the shock wave signals with different signal-to-noise ratio and different frequencies are analyzed,and the threshold value is obtained.Then the soft threshold de-noising based on the maximum posterior estimation is implemented,so the detection and extraction of the multi-peak shock wave test signal that is submerged in GAO Si's white noise is realized,which lays the foundation for the integrity analysis of the shock wave signal.(3)The interpolation algorithm of shock wave field modeling.In this paper,a modeling method of shock wave field based on radial basis function interpolation is proposed.The shock wave fields of explosion,large-caliber weapons and small-caliber weapons are modeled,respectively.Through cross-validation,the Shock wave modeling effects of inverse distance weighted interpolation,ordinary Kriging interpolation and cubic spline function interpolation are compared.The feasibility and effectiveness of the modeling are verified,and the precision of the modeling of shock wave field is improved.Further,using the principle of walking time orientation,using the radial basis function(RBF)interpolation to model the shock wave field at each time when the weapon is launched,and the propagation history of the shock wave in the middle and far field is simulated.It makes up for the deficiency of the precision of shock wave field caused by too many meshes and unstable boundary in numerical calculation.