A composite buffer has been designed to reduce the impact load of high-speed water entry projectile. Rigid Polyurethane (PU) foams of different densities have been used to make the damper of the buffer. A series of compression tests for PU foam specimens are implemented to obtain the stress-strain curves under different loading speeds. The constitutive model used in the simulation for PU foam has been validated by comparing the results with the experimental data. Six different failure modes have been found in the dynamic crushing process of the nose cap. The effects of PU foam density, the length of the nose cap on these failure modes are presented quantitatively by introducing a time-related non-dimensional number that represents the beginning time of each failure mode. The results show, the complete disintegration of the nose cap strongly depends on PU foam density, its effect is more pronounced in the cases when the ratio of the length of the buffer to the diameter of the projectile is greater than 0.92. The dedicated buffer is very efficient in reducing the impact load imposed in the cavitator of the projectile (the highest load-reducing ratio up to 51%).

设计了复合缓冲器以减少高速入水弹丸的冲击载荷。不同密度的刚性聚氨酯 (PU) 泡沫已被用于制造缓冲器的阻尼器。对聚氨酯泡沫试样进行了一系列压缩试验，以获得不同加载速度下的应力-应变曲线。通过将结果与实验数据进行比较，验证了用于 PU 泡沫模拟的本构模型。在鼻帽的动态破碎过程中发现了六种不同的失效模式。PU 泡沫密度、鼻帽长度对这些失效模式的影响通过引入一个与时间相关的无量纲数字来定量呈现，该数字代表每种失效模式的开始时间。结果显示，鼻帽的完全崩解很大程度上取决于PU泡沫密度，当缓冲器长度与弹丸直径之比大于0.92时，其效果更为明显。专用缓冲器对降低弹丸空化器的冲击载荷非常有效（最高减载率可达51%）。