论文标题
粘弹性和弹性材料之间界面的裂纹传播
Crack propagation at the interface between viscoelastic and elastic materials
论文作者
论文摘要
自1970年代以来，许多作者都使用了粘弹性材料中的裂纹繁殖。在聚合物和金属蠕变中，习惯假设放松的模量为零，因此我们通常具有裂纹速度，取决于应力强度因子的某些功率。通常，当有有限的模量有限时，已经表明，在阈值韧性G0处的一个非常低速的值之间的韧性增加，到杜松子酒的非常快速的断裂值，而在Infinite系统中的增强因子（经典的奇异骨折力学领域）中的增强因子简单地对应于宽松的弹性弹性弹性的弹性弹性。 在这里，我们为弹性材料和粘弹性材料之间的双层界面的情况应用了一个内聚模型，假设裂纹保留在界面处，并忽略了双层奇异性的细节。对于低速麦克斯韦材料的情况，裂纹以仅取决于粘度和应力强度因子的第四功率，而不取决于两种材料的弹性模量的速度。对于没有放松模量的Schapery类型的电力法律材料，有更多的一般结果。对于具有非零松弛模量的任意粘弹性材料，我们表明，相对于同质材料中的经典粘弹性裂纹的最大韧性增强将降低。
Crack propagation in viscoelastic materials has been understood with the use of Barenblatt cohesive models by many authors since the 1970's. In polymers and metal creep, it is customary to assume that the relaxed modulus is zero, so that we have typically a crack speed which depends on some power of the stress intensity factor. Generally, when there is a finite relaxed modulus, it has been shown that the toughness increases between a value at very low speeds at a threshold toughness G0, to a very fast fracture value at Ginf, and that the enhancement factor in infinite systems (where the classical singular fracture mechanics field dominates) simply corresponds to the ratio of instantaneous to relaxed elastic moduli. Here, we apply a cohesive model for the case of a bimaterial interface between an elastic and a viscoelastic material, assuming the crack remains at the interface, and neglect the details of bimaterial singularity. For the case of a Maxwell material at low speeds the crack propagates with a speed which depends only on viscosity, and the fourth power of the stress intensity factor, and not on the elastic moduli of either material. For the Schapery type of power law material with no relaxation modulus, there are more general results. For arbitrary viscoelastic materials with nonzero relaxed modulus, we show that the maximum toughness enhancement will be reduced with respect to that of a classical viscoelastic crack in homogeneous material.
