基于ANSYS的农机单轮测试装置结构设计与优化

设计一套测试轮胎型号介于6.00-12与9.5-20之间的单轮牵引性能测试试验装置。对比分析了滑轨-内外框架式与平行四连杆-内外框架式2种框架结构的优缺点,确定使用前者作为装置主体,液压马达作为驱动轮胎动力源。针对在试验过程中由于地面不平整而导致传感器测力方向不稳定的问题,设计了内外框架的整体结构:测力传感器布置于内外框架间,使用预紧弹簧使两端球铰式拉压传感器始终受到拉力。利用Pro/E软件建立了装置框架三维模型,同时建立了计算外框架最大应力的数学计算模型并进行了计算。利用有限元分析软件ANSYS对其内外框架进行应力应变仿真,最大应力结果与理论计算结果相近,并在此基础上进行了结构强度分析和优化。结果表明,优化后内外框架在保证框架总体重量最小的基础上应力应变明显减小,达到使用刚度、强度。针对内外框架试验时的振动特性进行了模态分析和预测,仿真后分别得到了内外框架前四阶的固有振动频率。

Design and optimization of a single wheel tester for agricultural machinery drive tires

A single wheel tester was designed for traction performance evaluation of farm machinery tires ranging from 6.00-12 to 9.5-20.By carefully studying and comparing the structural characters of the slide-frame and the parallel rods-frame, the former was chosen as main structure and a 30 kW electromotor-powered hydraulic motor was used as power source to drive the wheels.The structure of inner-outer frame was designed to overcome the testing instability on bumpy roads.Load cells were mounted between the inner-frame and outer-frame while two preloaded springs were employed to guarantee constant pulling on ball-and-socket load cells on the two sides.The tester was modeled in Pro/E and a mathematical model of the outer frame was established to calculate the maximum stress.Simulations for stress and deformation analysis were performed using the finite element analysis software ANSYS, and the value of maximum stress provided by the simulation was close to the theoretical calculation results, on which basis the structural strength was analyzed and optimized.The results showed that the optimized frame meetinged the rigidity and strength requirements with the least weight, and suffered from much less stress and deformation.Considering the vibration performance of the frames during the tests, modal analyses and forecasts were conducted.As the results of the simulation, the first order to the fouth order of the natural vibration frequency of the frames were obtained.