Four decades after the two countries established diplomatic ties, China-US relations have once again arrived at a crossroads. A China that adheres to the path of peace, cooperation and openness is an opportunity for r...Four decades after the two countries established diplomatic ties, China-US relations have once again arrived at a crossroads. A China that adheres to the path of peace, cooperation and openness is an opportunity for rather than a threat to the US; and a China that plays a constructive role in the international arena is a partner rather than an opponent of the US.展开更多
This paper presents the study of vibration in each element of hard disk drive, especially the resonance of the actuator arm. The resonance occurs in hard disk drive is considered as one of the quality controlled param...This paper presents the study of vibration in each element of hard disk drive, especially the resonance of the actuator arm. The resonance occurs in hard disk drive is considered as one of the quality controlled parameter. The main purpose of the research is to investigate the relationship between the pivot bearing assembly process and the natural frequency of the actuator arm. The experiment is designed using the information from the hard disk drive manufacturer. The selected pivot bearing assembly process parameters have been controlled. The modal analysis of the assembled actuator arms has been done. The experiment results show the relationship of the specific process parameters and some of the actuator arm＇s modal frequency. The results also show that the affected vibration mode is the torsion mode only.展开更多
Prestress enables the Glulam beam could make full use of the compression strength,and then increase the span,but it still could not reduce all drawbacks,such as cross-section weakening and small force arm.To avoid slo...Prestress enables the Glulam beam could make full use of the compression strength,and then increase the span,but it still could not reduce all drawbacks,such as cross-section weakening and small force arm.To avoid slotting and ensure suitable tension and compression couple,one kind of novel anchor has been proposed,which could meet the bearing capacity requirement.And then the bending test of prestressed Glulam beams with a geometric scale ratio of 1:2 was simulated,to investigate the effect of the force arm on bending capacities,failure modes,and deformation performance.Results show that increasing the force arm could improve the ultimate bending per-formance of the beam significantly,and the anchor arm length has a certain effect on the performance,but it is not obvious.Finally,based on Finite element method analysis,the practice design suggestions have been offered.展开更多
针对交叉滚子轴承人工装配存在的效率低、成本高和误差大等问题,设计一种4自由度机械臂,可对交叉滚子轴承进行自动装配。为提升机械臂的工作效率,以时间为适应度函数,提出了一种基于3-7-3多项式插值函数的改进灰狼算法(Improved Gray Wo...针对交叉滚子轴承人工装配存在的效率低、成本高和误差大等问题,设计一种4自由度机械臂,可对交叉滚子轴承进行自动装配。为提升机械臂的工作效率,以时间为适应度函数,提出了一种基于3-7-3多项式插值函数的改进灰狼算法(Improved Gray Wolf Optimizer,IGWO)对机械臂运动轨迹进行优化;该算法用非线性控制因子替代线性控制因子,并与天牛须搜索(Beetle Antennae Search,BAS)算法相结合,能够避免陷入局部最优,提高算法的求解效率和精度。仿真结果表明,与灰狼算法(Gray Wolf Optimizer,GWO)相比,改进灰狼算法运动时间缩短了17%,效率得到明显提升,且各个关节的轨迹曲线光滑连续。研究为机械臂的后续运动控制等奠定了基础。展开更多
文摘Four decades after the two countries established diplomatic ties, China-US relations have once again arrived at a crossroads. A China that adheres to the path of peace, cooperation and openness is an opportunity for rather than a threat to the US; and a China that plays a constructive role in the international arena is a partner rather than an opponent of the US.
文摘This paper presents the study of vibration in each element of hard disk drive, especially the resonance of the actuator arm. The resonance occurs in hard disk drive is considered as one of the quality controlled parameter. The main purpose of the research is to investigate the relationship between the pivot bearing assembly process and the natural frequency of the actuator arm. The experiment is designed using the information from the hard disk drive manufacturer. The selected pivot bearing assembly process parameters have been controlled. The modal analysis of the assembled actuator arms has been done. The experiment results show the relationship of the specific process parameters and some of the actuator arm＇s modal frequency. The results also show that the affected vibration mode is the torsion mode only.
基金supported by the Resources Industry Science and Technology Innovation Joint Funding Project of Nanping(N2021Z003)the Special Project of Service Industry Research of Wuyi University under Grant(2021XJFWCY03)+2 种基金the Research Launch Fund of Wuyi University’s Introduct Talent(YJ202309)the Fujian Training Program of Innovation and Entrepreneurship for Undergraduates(S202210397076)Research on the Stress Performance of Reinforced Bamboo Highway Guardrail with Embedded Channel Steel(LS202304).
文摘Prestress enables the Glulam beam could make full use of the compression strength,and then increase the span,but it still could not reduce all drawbacks,such as cross-section weakening and small force arm.To avoid slotting and ensure suitable tension and compression couple,one kind of novel anchor has been proposed,which could meet the bearing capacity requirement.And then the bending test of prestressed Glulam beams with a geometric scale ratio of 1:2 was simulated,to investigate the effect of the force arm on bending capacities,failure modes,and deformation performance.Results show that increasing the force arm could improve the ultimate bending per-formance of the beam significantly,and the anchor arm length has a certain effect on the performance,but it is not obvious.Finally,based on Finite element method analysis,the practice design suggestions have been offered.
文摘针对交叉滚子轴承人工装配存在的效率低、成本高和误差大等问题,设计一种4自由度机械臂,可对交叉滚子轴承进行自动装配。为提升机械臂的工作效率,以时间为适应度函数,提出了一种基于3-7-3多项式插值函数的改进灰狼算法(Improved Gray Wolf Optimizer,IGWO)对机械臂运动轨迹进行优化;该算法用非线性控制因子替代线性控制因子,并与天牛须搜索(Beetle Antennae Search,BAS)算法相结合,能够避免陷入局部最优,提高算法的求解效率和精度。仿真结果表明,与灰狼算法(Gray Wolf Optimizer,GWO)相比,改进灰狼算法运动时间缩短了17%,效率得到明显提升,且各个关节的轨迹曲线光滑连续。研究为机械臂的后续运动控制等奠定了基础。
