As recently suggested in an interesting and stimulating paper by Menga, Carbone and Dini (MCD), applying fracture mechanics energy concepts for the case of a sliding adhesive contact, imposing also the shear stress is constant at the interface and equal to a material constant (as it seems in experiments), leads to a increase of contact area which instead is never observed. We add that the MCD theory also predicts a size effect and hence a distortion of the JKR curve during sliding which is also not observed in experiments. Finally, a simpler example with the pure mode I contact case, leads in the MCD theory to an unbounded contact area, rather than a perhaps more correct limit of the Maugis-Dugdale solution for the adhesive sphere when Tabor parameter is zero, that is DMT's solution. We discuss that the MCD theory does not satisfy equilibrium, and we propose some more correct formulations, although they may be rather academic: recent semi-empirical models, with an appropriate choice of the empirical parameters, seem more promising and robust in modelling actual experiments.

中文翻译：

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在断裂力学中具有摩擦和附着力的滑动混合模式模型的应用。

正如Menga，Carbone和Dini（MCD）在一篇有趣且令人鼓舞的论文中所建议的那样，在滑动粘合剂接触的情况下应用了断裂力学能量概念，并且在界面处还施加了剪切应力恒定，并且等于材料常数（如在实验中所看到的那样）会导致接触面积的增加，而这种接触从未被观察到。我们补充说，MCD理论还预测了尺寸效应，因此预测了滑动过程中JKR曲线的变形，这在实验中也未观察到。最后，使用纯模式I接触情况的一个简单示例将MCD理论推向一个无边界的接触区域，而不是在Tabor参数为零（即DMT）时，对于胶粘剂球的Maugis-Dugdale解的一个更正确的极限。解。我们讨论了MCD理论不满足均衡的问题，