Hidalgo Raul Cruz, Kun Ferenc, Herrmann Hans J
Institute for Computational Physics, University of Stuttgart, Pfaffenwaldring 27, 70569 Stuttgart, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2002 Mar;65(3 Pt 1):032502. doi: 10.1103/PhysRevE.65.032502. Epub 2002 Feb 19.
We study the creep rupture of bundles of viscoelastic fibers occurring under uniaxial constant tensile loading. A fiber bundle model is introduced that combines the viscoelastic constitutive behavior and the strain controlled breaking of fibers. Analytical and numerical calculations showed that above a critical external load the deformation of the system monotonically increases in time resulting in global failure at a finite time t(f), while below the critical load the deformation tends to a constant value giving rise to an infinite lifetime. Our studies revealed that the nature of the transition between the two regimes, i.e., the behavior of t(f) at the critical load sigma(c), strongly depends on the range of load sharing: for global load sharing t(f) has a power law divergence at sigma(c) with a universal exponent of 0.5, however, for local load sharing the transition becomes abrupt: at the critical load t(f) jumps to a finite value, analogous to second- and first-order phase transitions, respectively. The acoustic response of the bundle during creep is also studied.
我们研究了在单轴恒定拉伸载荷下粘弹性纤维束的蠕变断裂。引入了一个纤维束模型，该模型结合了粘弹性本构行为和纤维的应变控制断裂。分析和数值计算表明，在临界外部载荷以上，系统的变形随时间单调增加，导致在有限时间(t_f)发生全局失效，而在临界载荷以下，变形趋于恒定值，从而产生无限寿命。我们的研究表明，两种状态之间转变的性质，即临界载荷(\sigma_c)下(t_f)的行为，强烈依赖于载荷分担范围：对于全局载荷分担，(t_f)在(\sigma_c)处具有幂律发散，通用指数为(0.5)，然而，对于局部载荷分担，转变变得突然：在临界载荷下(t_f)跃升至有限值，分别类似于二阶和一阶相变。还研究了束在蠕变过程中的声学响应。
