大多数动物有能力适应，到一些延长并且以环境的不同方法，变化或骚乱。在我们的实验，我们强迫了一条蚕毛虫旋转二，三或四由从茧拿出它的薄茧正在被构造。这些茧的机械性质被静态的张力的测试和动态机械热分析学习。尽管外部骚乱可以总共丝绸的重量由蚕旋转了的引起减少，渐渐的改进有趣地在这些薄茧的机械性质被发现。扫描茧的折断的标本的电子显微镜学观察在那里显示出那存在几不同精力驱散机制在宏同时发生了--，中央--，并且微规模，产出茧的一个优异能力从外面吸附可能的攻击的精力并且高效地保护它的蛹免于损坏。通过百万年的进化，因此，蚕 Bombyx 粗腐殖质 i 似乎增加了能力改编外部骚乱并且当它的第一茧为一些原因被损坏了时，与优化保护的功能重新设计新茧。
In this study,we theoretically investigate the dynamic indentation for measuring the loss (damping) factor of a linear viscoelastic material from its indentation response.A rigid indenter with arbitrary tip profile is assumed to indent into a viscoelastic substrate with arbitrary shape.We perform a theoretical analysis and identify the conditions under which the loss factor of the material can be determined from the phase angle between the applied harmonic indentation load and the corresponding harmonic displacement,a directly measurable quantity in a dynamic indentation test.To validate the conclusion drawn from our theoretical analysis,a series of numerical experiments are performed,including the spherical indentation of a soft layer with irregular surface morphology bonded to a rigid substrate,a conical indenter with tip defects indenting into a half-spherical particle,and the indentation of porous materials.This study may facilitate the use of the dynamic indentation technique to evaluate the damping properties of linear viscoelastic materials,including some advanced polymers and biological soft tissues.
