基于BP-GA的冲击破岩掘进机工作机构动态优化

Dynamic optimization of working mechanism for impacting and crushing rock road-header based on BP-GA

为了改善某型冲击破岩掘进机工作机构的动态性能,利用ANSYS Workbench建立有限元模型,通过模态分析和谐响应分析,得到其第1至第6阶固有频率和模态特性,确定了影响动态性能的模态频率;经灵敏度分析,确定了影响工作机构动态性能的主要结构参数;利用BP神经网络模型,建立所选结构参数与最大动应力、弯曲动刚度和钎杆顶端动位移间的映射关系,运用遗传算法对结构参数进行动态性能优化.结果表明,优化后工作机构的最大动位移和最大动应力分别减小27.5%和43.07%,固有频率提高24.7%,明显改善了工作机构的动态性能.

The finite element model was established by means of A N SY S Workbench for improvingdynamic performances of an impacting-crushing rock road-header working mechanism, the 1 to 6order natural frequencies and modal characteristics of the working mechanism were gotten by modalanalysis and harmonic analysis. The modal frequency which influenced the dynamic performanceof the working mechanism was determined. With sensitivity analysis,the main structural parameterswhich affected the dynamic performance of working mechanism were determined. Themapping relationships among structural parameters and the maximum dynamic stress,the bendingdynamic stiffness,the maximum dynamic displacement on the top of the drill rod were establishedby the BP neutral network. The dynamic performance optimization of the structural parameterswas realized by genetic algorithm. Application results indicated that the maximum dynamic displacementon the rod top decreased by 27. 5 % , the maximum dynamic stress decreased by 43. 07% , and the natural frequency increased by 24. 7 % after the optimization, indicated the dynamicperformance was improved obviously.