一种测量TBM滚刀受力的实验方法研究

为探索测量TBM掘进机滚刀受力特性的方法,本文提出了一种能够测试滚刀三向受力的方案。选择滚刀装配体上的垫块作为弹性体,以粘贴应变片的方式实现测量。利用数值计算方法找出垫块底端面和侧端面对所测力敏感而对作用力位置变化不敏感的区域作为贴片位置,分析了锁紧楔块对测试结果的影响。对滚刀装配体在不同工况下的受力情况进行了数值分析和实验测试。结果显示,若根据数值计算选定的位置贴片,垫块底端面和侧端面桥路应变总值的实验和数值结果相对误差介于1.06%和5.62%之间。滚刀强烈振动或更换刀具后可能使中心轴与垫块之间受力位置发生变化,结果确定其影响不超过2.75%。该方案不仅可以测出三个力的信号,还可用于分析滚刀振动状态,特别是滚刀发生偏磨后,刀刃与岩石之间强烈摩擦,振动状态与未偏磨时必然不同,因此还可通过分析由该方法测得的动态信号来识别偏磨。

An Experimental Measurement for Forces Acting on TBM Hobbing Cutters

In order to explore the method for force measurement of hobbing cutter mounted on tunnel boring machine (TBM), a scheme for measuring three-directional forces acting on hobbing cutter is proposed in this paper. Selecting the padding block on the hob assembly as an elastomer, the force measurement is achieved by sticking strain gauges. The optimal locations for sticking strain gauges at padding block bottom surface and side end are determined by numerical calculation, which are areas sensitive to force to be measured but not sensitive to the change of force acting position. The effect of locking wedge on the test results was analyzed. Numerical analysis and experimental measurement of hobbing cutter assembly were carried out under different conditions. Results show that according to sticking position at padding block bottom surface and side end selected by numeric calculation, the relative difference of total strains between numerical simulation and the experimental data is ranging between 1.06% and 5.62%. The force acting position on the interface between central axis and wedge may vary due to cutter strong vibration during tunneling and cutter renewal, the relative difference caused by above reasons is not larger than 2.75%. This approach is capable of measuring the signals of three-directional forces and analyzing its vibration modes, especially the intense friction between the blade and the rock due to cutter eccentric wearing. Since the vibration modes for cutter before and after eccentric wearing are different, this method can also be used to distinguish the cutter eccentric wearing occurrence.