The analysis of the problem of the finite length rod beingimpacted becomes very complex because viscoelasticity is introduced.

有限长细杆冲击问题的分析由于引入了粘弹性本构关系而变得比较复杂。

Whether the length of the rod returns to the original length.

棒子的长度是否，会回到原长。

Dr Fink's fibre consists of a hollow rod of an insulating polycarbonate material with a 30-micrometre ring of a piezoelectric polymer running along its length.

芬克博士研发出的这种纤维由一种由绝缘聚碳酸酯材料制成的空心杆组成，空心杆的内部有一种30微米的压电聚合物材料制成的环。