Abstract A new micromechanically motivated theory is proposed to model dragline silk. A thorough review of the micro-structure of dragline silk is presented. Based on the review, a continuum framework is utilized to develop constitutive equation of dragline silk. Dragline silk is composed of a dominant soft amorphous phase ( α -phase) and a reinforcing hard crystal phase, which is classified as rigid β -sheets and extremely soft β -spirals. These two different β -fillers have completely different effects on the mechanical behaviors of dragline silk. The former results in the Mullins effect while the latter produces plastic deformation. Both these effects result in energy dissipation. In addition to these effects, the damping effect due to finite viscoelasticity is accounted for by using a double network model. Moreover, the highly oriented chains in the amorphous phase are modeled as an anisotropic network model. It is found that the proposed model accurately captures the complex mechanical behavior of dragline silk subjected to cyclic loading with merely 7 “physically-based” material constants.

中文翻译：

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一种新的拉铲丝本构模型

摘要 提出了一种新的微机械驱动理论来模拟拉铲丝。对拉索丝的微观结构进行了全面审查。在综述的基础上，利用连续体框架来开发拉铲丝的本构方程。拉绳丝由占主导地位的软非晶相（α-相）和增强的硬晶相组成，分为刚性β-片层和极软的β-螺旋。这两种不同的β-填料对拉索丝的力学行为有完全不同的影响。前者产生穆林斯效应，而后者产生塑性变形。这两种效应都会导致能量耗散。除了这些影响之外，由于有限粘弹性引起的阻尼效应通过使用双网络模型来解释。而且，非晶相中高度定向的链被建模为各向异性网络模型。结果表明，所提出的模型仅用 7 个“基于物理的”材料常数就可以准确地捕捉拉铲丝在循环载荷下的复杂机械行为。