Optimization of actuator/sensor position of multi-body system with quick startup and brake

A new method was put forward to optimize the position of actuator/sensor of multi-body system with quick startup and brake. Dynamical equation was established for the system with intelligent structure of piezoelectric actuators. According to the property of the modes varying with time, the performance index function was developed based on the optimal configuration principle of energy maximal dissipation, and the relevant optimal model was obtained. According to its characteristic, a float-encoding genetic algorithm, which is efficient, simple and excellent for solving the global-optimal solution of this problem, was adopted. Taking the plane manipulator as an example, the result of numerical calculation shows that, after the actuator/sensor position being optimized, the vibration amplitude of the multi-body system is reduced by 35% compared with that without optimization.     

电动轮自卸车整车模态分析

大型电动轮自卸车是目前矿山运输的主要没备，由于其结构复杂，整车质量大并且载荷重，行驶道路特殊，整车运行中会产生扭转，弯曲等变形，各部件的相对位置会发生变化，当发生共振时，会引起磨损加剧，甚至造成事故，但我们不可能像公路车辆一样，通过实验室试验装置来模拟车辆运动和载荷，获得试验数据。     

Constitutive relationship of ionic polymer-metal composite and static response character of its cantilever setup to voltage

As a new ionic polymer-metal composite（IPMC） for artificial muscle,the mechanical performance parameters and the relationship between the deformation and the electrical parameters of the IPMC were studied. With the digital speckle correlation method,the constitutive relationship of the IPMC was confirmed. With non-contact photography measurement,a cantilever setup was designed to confirm the relationship between the deformation of the IPMC film and the applied voltage. The relationship curve of tip displacement of the IPMC cantilever setup vs the voltage was achieved. The results indicate that the IPMC is isotropic,its elastic modulus is 232 MPa and Poisson ratio is 0.163. The curve achieved from the test of the tip displacement of the IPMC cantilever setup shows that the tip displacement reaches the maximum when the stimulated voltage is 5 V. And the tip displacement descends largely when the frequency of the applied voltage is between 30 mHz and 100 mHz.     

矿用自卸车牵引梁结构分析及改进设计

建立车架中部牵引梁2种方案（方案一：圆形截面结构牵引梁;方案二：正八边形截面结构牵引梁）的三维模型和有限元模型,在边界条件相同的情况下,选择极限工况对2种方案进行强度和刚度的计算、分析、比较。其强度和刚度计算结果为：方案一最大应力为141.5 MPa,最大变形为 0.53 mm;方案二最大应力为 137.5 MPa,最大变形为0.503 mm;从计算结果上看,方案二的应力和变形均小于方案一,所以方案一为较优方案。从制作工艺上对2种方案进行比较,方案一中牵引梁为大直径圆形截面结构,需要用专用设备进行成型加工,制作工艺复杂;方案二中牵引梁为正八边形截面结构,可有2块钢板分别折弯、对焊而成,制作工艺简单,从工艺上可以得出方案二为较优方案。比较得出,方案二正八边形截面结构牵引梁的强度和刚度均能满足要求,工艺性更好,为较优方案。     

ANSYS的电动矿用自卸车有限元模态分析

利用ANSYS有限元软件分别建立了220t电动矿用自卸车的整车和车架的有限元模型,得出自卸车整车的低阶固有频率和振型,并进行对比.结果显示:在低阶振动模态中,车架前端的刚度相对较低;整车和车架的固有频率均不在发动机的振动频率范围内,避免了发生共振;整车和车架的相同振型的固有频率差别在5%以内.     

220t矿用自卸车强度有限元分析

建立220 t矿用自卸车有限元模型,通过合理处理模型及外载荷施加方法,对整车在满载静止及极限载荷条件2种工况下的结构强度进行了分析.模拟结果显示,整车结构应力分布较为均匀、合理,具有较充足的安全系数.