基于达朗贝尔原理结合牛顿欧拉法和有限单元的方法建立机头展收机构的动力学模型,牛顿欧拉法为刚体力学模型,有限单元法属于弹性体力学模型,牛顿欧拉法计算的轴力最大值为137 k N,而有限单元法的轴力极值达到720 k N。计算结果表明:有...基于达朗贝尔原理结合牛顿欧拉法和有限单元的方法建立机头展收机构的动力学模型,牛顿欧拉法为刚体力学模型,有限单元法属于弹性体力学模型,牛顿欧拉法计算的轴力最大值为137 k N,而有限单元法的轴力极值达到720 k N。计算结果表明:有限单元法计算的液压变幅构件轴力曲线变化平稳,但计算量较大;牛顿欧拉法计算量小,但容易产生轴力曲线波动失真现象。牛顿欧拉法和有限单元法在机构设计前期为确定液压变幅构件的轴力提供科学凭据,有助于设计出性能优越的机头展收机构液压装置。展开更多
The collision and wear caused by inevitable clearance in kinematic pair have an effect on the dynamic characteristics of the mechanism.Therefore,we established the dynamic model of a 3RSR(R is the revolute joint and S...The collision and wear caused by inevitable clearance in kinematic pair have an effect on the dynamic characteristics of the mechanism.Therefore,we established the dynamic model of a 3RSR(R is the revolute joint and S is the spherical joint)parallel mechanism with spherical joint clearance based on the modified Flores contact force model and the modified Coulomb friction model using Newton-Euler method.The standard quaternion was introduced in the constraint equation,and the four-order Runge-Kutta method was adopted to solve the 3RSR dynamic model.The simulation results were compared and analyzed with the numerical results.The geometrical parameters of the worn ball socket were solved based on the Archard wear model,and the geometrical reconstruction of the worn surface was carried out.The geometric reconstruction parameters were substituted into the dynamic model,which was to analyze the dynamic response of the 3RSR parallel mechanism with wear and spherical joint clearance.The simulation results show that the irregular wear occurs in the spherical joint with clearance under the presence of the impact and friction force.The long-term wear will increase the fluctuation of the contact force,thereby decreasing the movement stability of the mechanism.展开更多
文摘基于达朗贝尔原理结合牛顿欧拉法和有限单元的方法建立机头展收机构的动力学模型,牛顿欧拉法为刚体力学模型,有限单元法属于弹性体力学模型,牛顿欧拉法计算的轴力最大值为137 k N,而有限单元法的轴力极值达到720 k N。计算结果表明:有限单元法计算的液压变幅构件轴力曲线变化平稳,但计算量较大;牛顿欧拉法计算量小,但容易产生轴力曲线波动失真现象。牛顿欧拉法和有限单元法在机构设计前期为确定液压变幅构件的轴力提供科学凭据,有助于设计出性能优越的机头展收机构液压装置。
基金Project(2018YFB1307900)supported by the National Key R&D Program of ChinaProject(51775473)supported by the National Natural Science Foundation of China+3 种基金Projects(E2018203140,E2019203109)supported by the Natural Science Foundation of Hebei Province,ChinaProject(ZD2019020)supported by the Key Research Project in Higher Education Institutions of Hebei Province,ChinaProject(2017KSYS009)supported by the Key Laboratory of Robotics and Intelligent Equipment of Guangdong Regular Institutions of Higher Education,ChinaProject(KCYCXPT2017006)supported by the Innovation Center of Robotics and Intelligent Equipment of Dongguan University of Technology,China。
文摘The collision and wear caused by inevitable clearance in kinematic pair have an effect on the dynamic characteristics of the mechanism.Therefore,we established the dynamic model of a 3RSR(R is the revolute joint and S is the spherical joint)parallel mechanism with spherical joint clearance based on the modified Flores contact force model and the modified Coulomb friction model using Newton-Euler method.The standard quaternion was introduced in the constraint equation,and the four-order Runge-Kutta method was adopted to solve the 3RSR dynamic model.The simulation results were compared and analyzed with the numerical results.The geometrical parameters of the worn ball socket were solved based on the Archard wear model,and the geometrical reconstruction of the worn surface was carried out.The geometric reconstruction parameters were substituted into the dynamic model,which was to analyze the dynamic response of the 3RSR parallel mechanism with wear and spherical joint clearance.The simulation results show that the irregular wear occurs in the spherical joint with clearance under the presence of the impact and friction force.The long-term wear will increase the fluctuation of the contact force,thereby decreasing the movement stability of the mechanism.
