In order to further analyze the influence of clearance on the kinematic performance of spatial linkage weft insertion mechanism,it is necessary to study the dynamic characteristics of contact impact force model with t...In order to further analyze the influence of clearance on the kinematic performance of spatial linkage weft insertion mechanism,it is necessary to study the dynamic characteristics of contact impact force model with the variable stiffness and damping coefficient.Firstly,the parameters in the output process of the system are solved by describing of the flexible joint clearance.Then,based on Lankarani-Nikravesh contact force model,the contact impact stiffness and damping coefficient is modified from fixed values to time-varying coefficients.The dynamic model of spatial linkage weft insertion mechanism with modified clearance is established by Lagrange method,and the dynamic characteristics of the system are calculated.The results show that the joint clearance can directly affect the output performance of the mechanism.With the increase of the clearance value,the curve fluctuations of acceleration,driving torque and collision force are obvious,and it will be further intensified with the increase of spindle speed,which greatly affects the stability of mechanism and fabric quality.Finally,the virtual prototype is established by the SolidWorks software and simulated by the ADAMS software.The simulation results are compared with the numerical results,which verifies the accuracy of the modeling method in this paper.展开更多
目的:观察体外冲击波碎石对不同部位肾结石非靶区的影响。方法:将6 149例肾结石患者分为肾上盏结石组、肾中盏结石组和肾下盏结石组,对比分析不同部位肾结石非靶区的肾脏CT灌注图像参数、排石成功率及并发症率差异。结果:体外冲击波碎...目的:观察体外冲击波碎石对不同部位肾结石非靶区的影响。方法:将6 149例肾结石患者分为肾上盏结石组、肾中盏结石组和肾下盏结石组,对比分析不同部位肾结石非靶区的肾脏CT灌注图像参数、排石成功率及并发症率差异。结果:体外冲击波碎石术均对结石患者术后肾结石非靶区均有所损伤,且体外冲击波能量大于11 k V时肾损伤程度迅速提升;E<9能量波碎石的排石成功率明显高于E≥9能量波碎石,E≥11能量波碎石的并发症率低于E<11能量波碎石。结论:当冲击波能量在9~11 k V区间时,不仅对患者非靶区损伤影响较低,而且排石成功率和并发症发生率也较低,冲击波能量选择在9~11 k V区间是肾结石患者治疗的最优能量方案。展开更多
基金National Natural Science Foundation of China(No.11402186)Innovative Research Team in University of Tianjin,China(No.TD13-5037)Natural Science Foundation of Tianjin,China(Nos.14JCQNJC05600 and 18JCQNJC05300)。
文摘In order to further analyze the influence of clearance on the kinematic performance of spatial linkage weft insertion mechanism,it is necessary to study the dynamic characteristics of contact impact force model with the variable stiffness and damping coefficient.Firstly,the parameters in the output process of the system are solved by describing of the flexible joint clearance.Then,based on Lankarani-Nikravesh contact force model,the contact impact stiffness and damping coefficient is modified from fixed values to time-varying coefficients.The dynamic model of spatial linkage weft insertion mechanism with modified clearance is established by Lagrange method,and the dynamic characteristics of the system are calculated.The results show that the joint clearance can directly affect the output performance of the mechanism.With the increase of the clearance value,the curve fluctuations of acceleration,driving torque and collision force are obvious,and it will be further intensified with the increase of spindle speed,which greatly affects the stability of mechanism and fabric quality.Finally,the virtual prototype is established by the SolidWorks software and simulated by the ADAMS software.The simulation results are compared with the numerical results,which verifies the accuracy of the modeling method in this paper.
文摘目的:观察体外冲击波碎石对不同部位肾结石非靶区的影响。方法:将6 149例肾结石患者分为肾上盏结石组、肾中盏结石组和肾下盏结石组,对比分析不同部位肾结石非靶区的肾脏CT灌注图像参数、排石成功率及并发症率差异。结果:体外冲击波碎石术均对结石患者术后肾结石非靶区均有所损伤,且体外冲击波能量大于11 k V时肾损伤程度迅速提升;E<9能量波碎石的排石成功率明显高于E≥9能量波碎石,E≥11能量波碎石的并发症率低于E<11能量波碎石。结论:当冲击波能量在9~11 k V区间时,不仅对患者非靶区损伤影响较低,而且排石成功率和并发症发生率也较低,冲击波能量选择在9~11 k V区间是肾结石患者治疗的最优能量方案。
