Static Explosion Field Reconstruction Based on the Improved Biharmonic Spline Interpolation

To obtain the peak pressure distribution of explosion field near the ground, an improved reconstruction method for interpolation of blast overpressure data from the finite measuring points was studied. According to the peak attenuation law of shock wave on the propagation path and the attenuation characteristic of the wave front after passing through the measured points, the polynomial fitting function of peak attenuation of shock wave near the ground is constructed by using the least square method. Using the peak attenuation polynomial of shock wave constrain the radial interpolation of biharmonic spline surface interpolation algorithm (BSSIA) to realize the interpolation conforming the propagation law of shock wave and ensure the interpolation convergence. The root-mean-squared error (RMSE) and the maximum relative error (MRE) before and after the improvement were computed by comparing the peaks with empirical formula data. The improvement is evident as the RMSE decreased from 14.12kPa to 0.22kPa and the MRE decreased from 23.91% to 0.37%. The peak reconstructed by the improved biharmonic spline surface interpolation algorithm (IBSSIA) and BSSIA with test data, the overpressure peak distribution obtained by IBSSIA is in good agreement with empirical result and consistent with the explosion image.