斗轮堆取料机超长悬臂散料-结构动力耦合振动特性及抑制

The vibration of the long cantilever is an important indicator for evaluating the quality and safety performance of bucket wheel excavator. Due to the complex dynamic coupling between the bulk material and the structure, the bucket wheel excavator is subjected to the strong dynamic loads. This lead to the vibration problem of the cantilever beam is very prominent during mining process. So, this project is intended to start from the excitation source of cantilever vibration. For the dynamic characteristics of the bulk material-structure coupling, the dynamic simulation model of the mining process is established by adopting the discrete element-finite element coupling method. The excitation mechanism and the characteristics of the excitation sources are discussed, such as resistance-to- excavation, strokes of the fragments of the bulk material, unbalance of bucket wheel, unbalance of the conveyor belt, and so on. So the variation of characteristics of the excitation source with the material characteristics of bulk material and operating conditions is revealed. In addition, the dynamic model of the cantilever under the multi-source excitation is constructed, and the influence of the structural parameters on the cantilever vibration response is studied. So the variation of the cantilever vibration response with the structural parameters of the key structures under the multi-source excitation is revealed. Based on this, the cantilever vibration suppression methods are brought up accordingly through optimizing working condition parameters and the structural parameters, respectively. The project research can provide the theoretical basis and technical support for the dynamic design, structural optimization and vibration suppression of long cantilever structures of bucket wheel excavator and other equipment.

超长悬臂的振动特性是评价斗轮堆取料机质量和生产安全性能的重要指标。由于作业中散料-结构之间复杂的动力耦合作用，斗轮堆取料机工作载荷具有强烈的动态特性，导致取料过程中悬臂梁的振动问题非常突出。项目拟从斗轮机悬臂振动的激励源入手，针对散料-结构相互耦合的动力特性，采用离散元-有限元耦合法建立取料作业的动态仿真模型，研究挖掘阻力、落料冲击、斗轮偏载转动不平衡、传送带偏载不平衡等激励源的形成机理与特性，揭示激励源特性随物料特性和运行工况参数的变化规律；构建悬臂的动力学响应模型，分析多源动载激励下悬臂动力学响应特性，研究结构参数对振动响应的影响，揭示多源激励下悬臂振动响应随关键结构参数的变化规律；基于此，从工况参数、结构参数优化的角度，提出相应的悬臂振动抑制方法。项目研究可为斗轮机等设备超长悬臂的动力学设计、结构优化与振动抑制提供理论依据和技术支撑。

超长悬臂的振动特性是评价斗轮堆取料机质量和生产安全性能的重要指标。由于作业中散料-结构之间复杂的动力耦合作用，斗轮堆取料机工作载荷具有强烈的动态特性，导致取料过程中悬臂梁的振动问题非常突出。项目从斗轮机悬臂振动的激励源入手，提出了基于表面能的湿颗粒表征方法，针对散料-结构相互耦合的动力特性，采用离散元-有限元耦合法建立了取料作业的动态仿真模型，形成了斗轮机取料载荷准确计算技术；针对传统力锤激振动法难以激励起大型装备的低频振动问题，提出了基于托辊激振法的大型斗轮机悬臂低频振动测试方法，形成了大型装备低频振动激振技术；基于耦合模型与DOE分析方法，设计正交试验进行仿真，基于仿真结果构建了激励源与悬臂动力学特性的数值响应面，揭示了激励源与悬臂振动特性随物料特性和运行工况参数的变化规律；基于此，从工况参数、结构参数优化的角度，提出了悬臂振动的有效抑制方法，形成了斗轮机的振动抑制与结构优化技术。项目研究成果可为斗轮机载荷的准确计算、设备低频振动测试及抑制、结构的动力学及优化设计提供技术依据，同时为同类装备的振动分析与运行维护提供了理论支撑。