When aluminum is hit, you can see a dent. Composites, though, spring back to the original shape, which could hide internal damage.

但是也有一个很大的缺点：当铝被撞击时，你会看到一个凹陷，但是复合材料看似能够变回原来的外表，内部却已经受损。

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However, the harsh Marine environment makes submarine pipes inevitably produce dent, crack and other damage.

然而，恶劣的海洋环境使得海底管道不可避免地产生凹痕、裂纹等各种损伤。

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Relation between the dent depth and the impact energy indicates that the variation of pit depth is consistent with the energy, and detailed analysis of damage distribution and size was conducted.

冲击凹坑深度与冲击能量的关系表明，凹坑深度的变化是与冲击能量的变化过程相适应的，在此基础上对损伤的分布形式及大小做了详细的分析。

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