为了分析PDC全钻头破岩中单齿受力,一方面通过对比不同切削参数影响下,PDC单齿破岩数值模拟中采用的Mohr—Coulomb本构模型与Drucker Prager本构模型计算结果,评判了模型的计算效率与精度;另一方面进行了PDC全钻头破岩试验,建立了同比条件下更为精细化网格的PDC全钻头破岩有限元模型,将数值模拟结果与试验结果进行了对比。分析结果表明,在不同的工况下,Mohr—Coulomb模型计算的结果误差虽然比Drucker Prager模型略高,但Mohr—Coulomh模型的计算效率是Drucker Prager模型的3.1倍;仿真钻压的平均值误差为2.75%,平均扭矩误差为0.40%,满足工程要求。因此可以利用数值模拟方法研究布齿参数变化对切削工作载荷分布的影响,为个性化的PDC钻头研发提供技术支撑。
In order to analyze single cutter stress of PDC bits during rock breaking, this paper compares the calculation results obtained by Mohr-Coulomb constitutive model and Drucker Prager constitutive model in numeri- cal simulation of PDC single cutter rock breaking under the influence of different cutting parameters, so as to judge calculation efficiency and precision of the models. Moreover, through rock breaking experiment of PDC bits, this paper presents a finite element model of PDC bits rock breaking with more refined mesh compared with the same conditions, and makes a comparison between simulation results and experimental results. The analysis results show that, although the error of calculation result of Mohr-Coulomb model is slightly higher than that of Drucker Prager model under different working conditions, the calculation efficiency of the former is 3.1 times that of the later. The mean value error of simulation drilling pressure is 2.75%, with mean torque error of 0.40%, meeting engineering requirements. Therefore, the numerical simulation method can be adopted to identify the impact of cutter distribu- tion parameter change on load distribution of cutwork, thus providing technical support for research and develop- ment of individual PDC bits.