Multicracking of a thin brittle layer deposited on a substrate with an intermetallic layer is studied using finite fracture mechanics. Nonlinear implementation of the coupled criterion is used to predict the initiation and successive subdivisions of a periodic network of cracks considering intermetallic layer plasticity and interface debonding. Plasticity has a moderate influence on the cracking kinetics whereas debonding length has a strong influence on the saturation crack spacing. The cracking kinetics predicted numerically is more abrupt than in experiments because of the periodicity assumption, however crack spacing at saturation similar to those measured experimentally are obtained. The tensile strength and critical energy release rate of the thin brittle layer are determined by inverse identification based on the crack density variation as a function of the imposed loading. The proposed approach also enables the accurate determination of the interface critical energy release rate based on the experimentally measured debonding lengths.

中文翻译：

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脱粘和基底塑性对薄膜多重裂纹的影响

使用有限断裂力学研究了沉积在具有金属间化合物层的基底上的薄脆层的多重裂纹。考虑金属间层塑性和界面脱粘，耦合准则的非线性实现用于预测周期性裂纹网络的萌生和连续细分。塑性对裂纹动力学有中等影响，而脱粘长度对饱和裂纹间距有很大影响。由于周期性假设，数值预测的裂纹动力学比实验中的裂纹动力学更突然，但是获得的饱和裂纹间距与实验测量的裂纹间距相似。薄脆层的拉伸强度和临界能量释放率是通过基于裂纹密度随施加载荷的变化而变化的逆辨识来确定的。所提出的方法还能够根据实验测量的脱粘长度准确确定界面临界能量释放率。