瑞利随机分布下滚筒截割载荷重构算法与数值模拟

摘要

为了获得滚筒截割载荷特性曲线,对截齿与滚筒的受力进行了分析研究,得到了截齿轴向阻力与滚筒截割载荷的数值关系,运用自制的多截齿旋转截割煤岩实验设备,进行了截齿截割煤岩实验,得到了截齿三向力曲线,建立了滚筒截割载荷随机载荷曲线重构模型,给出了载荷重构算法,利用测试数据对滚筒截割载荷进行了数值模拟,得到了滚筒截割载荷重构载荷谱.研究结果表明:实验条件下煤岩崩落周期约为0.04 s,滚筒截割载荷数值上大于滚筒上各截齿同一时刻各截割阻力之和;滚筒截割载荷与参与截割的截齿截割阻力峰值、随机分布状态、截齿位置角、煤岩崩落周期及各截齿作用位置有关;所提算法与修正离散正则化算法比较,计算速度提高了约70倍,少样本数据下,该算法精度优于修正离散正则化算法,但重构数据只在重构点处具有真实性;使用改进的FFT算法进行重构曲线数值拟合,与FFT算法相比,计算量减小为原来的1/16,计算速度提高了约27倍,拟合优度相同,均为0.94,拟合曲线在总体趋势上比较平滑,呈现月牙形,与截割厚度变化规律一致,波形特征比较容易辨识,特征值便于判断和提取.研究结果为截齿三向力与滚筒截割载荷的关联提供依据,同时为滚筒截割载荷重构及数值拟合提供高效便捷的算法.%In order to obtain the drum cutting load characteristic curve,the relationship between the axial resistance of picks and cutting load of drum was obtained by analyzing the force of pick and drum.The experiment was carried out that the coal was cut with multiple picks rotation cutting by using self-made laboratory equipment.And the picks force curve was obtained,the drum random load spectrum reconstruction model was established and the load reconstruction algorithm was presented.The drum cutting load was simulated by using the test data and the load spectrum of drum cutting load was obtained.The results show that the coal caving cycle is about 0.04 s under the experimental conditions,and the drum cutting resistance is greater than the one of the picks at the same moment.The drum cutting resistance is related to the picks resistance peak,random distribution,pick position angle,coal caving cycles and cutter tooth position.Compared with the modified discrete regularization algorithm,the computational speed is improved by about 70 times,and the accuracy of the algorithm is better than that of the modified discrete regularization algorithm under less sample data.However,the reconstructed data only have the authenticity at the reconstruction point.Improved FFT algorithm that the amount of calculation is reduced to the 1/16 of original and the calculation speed is increased by about 27 times with the same accuracy.The fitting curve is smooth in the overall trend,showing crescent shape,consistent with the cutting thickness variation,the fitting goodness is 0.94,the waveform characteristic is easy to identify,and the eigenvalue is easy to judge and extract.The results provide the basis for the correlation of the threedirection force and the drum cutting load,and provide an efficient and convenient algorithm for the drum cutting load reconstruction.