Accurate determination of contact stresses in continuous mining cutters using variational inequalities

采矿中有两种主要的钻井类型：勘探钻井和（或）生产钻井。前者需要使用金刚石钻头进行旋转破碎，而后者需要使用带有多个硬质合金或硬质合金刀片的钻头进行冲击锤击。在冲击法中，钻孔随后被填满炸药，使岩石和/或矿体爆破松动。这种过程需要严格的安全措施来保护矿工和周围环境，因此限制了生产率和成本效益。因此，连续采矿系统（CMS）在勘探和/或生产钻井中是最有效的。路挡块一直是高硬度的地面材料。到目前为止，CMS的关键部件是刀头和刀尖。刀具尖端承受非常高的接触应力和热量。为了防止切削齿尖端破裂、剥落和磨损，有必要彻底了解由此产生的接触应力。赫兹经典的接触理论由于其严格的限制而不适合。此外，目前的有限元代码依赖于使用涉及用户自定义参数的接触单元，这对解的收敛性和精度有不良影响。

There exist two major types of drilling in mining: exploration and/or production drilling. The former involves rotational crushing using diamond bits, while the latter involves percussive hammering using drill bits with multiple hardmetal or carbide inserts. In percussive hammering, the drilled holes are subsequently filled with explosives to blast loose the rock and/or ore body. Such a process requires stringent safety measures to protect the miners and surroundings, and as a result limits productivity and cost effectiveness. Therefore, a continuous mining system (CMS) would be most effective in exploration and/or production drilling. The road block has been the high hardness of the ground materials. The key component by far in CMS is the cutter head and tip. The cutter tip is subjected to very high contact stresses and heat. To prevent cutter tips from fracturing and spalling and wear, a thorough understanding of the resulting contact stresses is necessary. Hertz classical theory of contact is unsuitable because of its severe restrictions. In addition, current finite element codes rely on the use of contact elements that involve user-defined parameters, which have undesirable effects on the convergence and the accuracy of the solution.