环形复合内衬头盔冲击波防护性能研究

The shock wave protection ability is the main performance index of individual soldier helmet, which is of great significance to improve solider battlefield survivability. To improve the protective effect of the individual soldier helmet against shock wave,the structure and arrangement of the liner of advanced combat helmet (ACH) are explored,and a design of ring-shaped outer edge liner is proposed,and its protective effect is evaluated. The protection performances of helmets with different structures and sizes of outer edge liner are tested in shock tube and real explosion field. The waveform and peak values of shock wave on the forehead,top and rear of head model are compared and analyzed. The experimental results show that,after wearing the helmet,the shock wave mainly enters through the gap between the helmet and head in diffraction form,and the accumulation and superposition of shock waves in the gap may increase the pressure. In addition,the local high pressure region which is far from the incoming wave is easy to form because of the underwash effect. The annular composite liner composited with polyurea-polyurethane foam-sponge can effectively prevent the diffraction wave from entering the inside of the helmet and reduce the superposition effect of diffraction wave. The attenuation rate of shock wave overpressure at each measuring point can reach more than 40% after wearing the helmet with annular composite liner. The smaller the gap formed during the shock wave action is under the condition of the incident shock wave (weak shock wave),the better the protective effect is. When the width of polyurea-polyurethane foam reaches 15 mm,the outer edge liner and the head model have the best fit degree and the protection effect is optimal. The experimental results show that the overpressure attenuation rates at the measuring points on forehead,top,and rear of head can reach 92. 26%,88. 82%,and 87. 19%,respectively.