To reduce the amount of labor in the sheet metal stamping industry, improve the processing efficiency and safety factor and realize the automatic production of stamping, this paper designs a new type of overall plan a...To reduce the amount of labor in the sheet metal stamping industry, improve the processing efficiency and safety factor and realize the automatic production of stamping, this paper designs a new type of overall plan about automatic loading and unloading material manipulator for telescopic punch which can realize the telescopic movements with two degrees. The mechanical structure of the manipulator includes a lifting device and a telescopic device. Using PLC control program, the control system can automatically achieve continuous beat actions of drawing and stacking for the processing raw materials. According to the mechanical structure, the paper analyzes the working principle and control strategy of each component in the loading-and-unloading material manipulator systems.展开更多
In this paper, Dynamic Relaxation Method is applied to study the postbuckling path of cylindrically curved panels of laminated composite materials during loading and unloading. The phenomenon that loading paths do not...In this paper, Dynamic Relaxation Method is applied to study the postbuckling path of cylindrically curved panels of laminated composite materials during loading and unloading. The phenomenon that loading paths do not coincide with unloading paths has been found. Numerical results are given for cylindrically curved cross-ply panels subjected to uniform uniaxial compression under two types of boundary conditions. The influence of the number of layers, the panels curvature and the initial imperfection on the postbuckling paths is discussed.展开更多
In order to achieve workpiece′s automatic loading-and-unloading, this paper designs a manipulator. Use the vacuum chuck mechanism to achieve the function of reclaiming and the cylinder rails to achieve the function o...In order to achieve workpiece′s automatic loading-and-unloading, this paper designs a manipulator. Use the vacuum chuck mechanism to achieve the function of reclaiming and the cylinder rails to achieve the function of pick-feeding materials. PLC control technology is applied to control system and improve the efficiency and reduce human labor.To ensure the strength,Solidworks simulation performs thestress and strain analysis to verify material strength.展开更多
The mechanical properties are essentially different when rock material is subjected to loading or unloading conditions. In this study, loading and unloading tests with various confining pressures are conducted to inve...The mechanical properties are essentially different when rock material is subjected to loading or unloading conditions. In this study, loading and unloading tests with various confining pressures are conducted to investigate the mechanical properties of marble material samples taken from the deep diversion tunnels of Jinping II Hydropower Station. The stress-strain relationship, failure characteristics and strength criterion are compared and analyzed based on the experiment results. The results show： in the loading and unloading test, peak strength, lateral strain, axial strain and plastic deformation increase significantly as the confining pressure increases. Lateral strain increased significantly and obvious lateral dilatancy can be observed to the change of confining pressure; The fracture mode is mainly the single shear fracture for the triaxial compression test and post-peak test, angle between the failure surface and the ends of the rock material becomes smaller as the confining pressure increases. Hock-Brown strength criterion reflects the strength characteristics of marble material under two different unloading conditions, and has some supplementary effects to the rock material of mechanical field.展开更多
煤矿井下作业环境复杂多变,钻探成为煤矿开采的必备环节。钻杆加卸是钻探过程中的重要步骤,传统的人工钻杆加卸方式不仅耗时费力,而且劳动强度极大,对工人的身体健康构成严重威胁。为了提高煤矿井下钻机的钻杆加卸效率,降低劳动强度,提...煤矿井下作业环境复杂多变,钻探成为煤矿开采的必备环节。钻杆加卸是钻探过程中的重要步骤,传统的人工钻杆加卸方式不仅耗时费力,而且劳动强度极大,对工人的身体健康构成严重威胁。为了提高煤矿井下钻机的钻杆加卸效率,降低劳动强度,提升作业安全性,探讨并总结当前煤矿井下智能化钻机配套钻杆自动加卸技术,发现多轴液驱机械手式换杆技术具有高度的灵活性和适应性,可作为解决多规格钻具自动加卸问题的有效方案。基于当前机械手关键技术的研究,分析得出动态路径规划方法是多轴机械手式钻杆加卸系统研究的难点,在总结当前机械手动态轨迹规划领域研究进展的基础上,分析现有路径规划方法的优缺点,特别是在动态环境下的适应性表现。在此基础上,研究了基于快速随机搜索树(Rapidly-exploring Random Tree,RRT)算法的混合轨迹规划策略在复杂环境下的应用,展示了这些方法在提升机械手路径规划精度、减少操作时间以及增强系统鲁棒性方面展现出的显著优势。针对未来研究方向,提出了进一步提升机械手动态轨迹规划算法性能,增强机械手自主作业能力,推动煤矿井下自动化技术全面应用的建议。展开更多
基金Supported by Science and Technology Research Project of Anhui Province(15czz02030)
文摘To reduce the amount of labor in the sheet metal stamping industry, improve the processing efficiency and safety factor and realize the automatic production of stamping, this paper designs a new type of overall plan about automatic loading and unloading material manipulator for telescopic punch which can realize the telescopic movements with two degrees. The mechanical structure of the manipulator includes a lifting device and a telescopic device. Using PLC control program, the control system can automatically achieve continuous beat actions of drawing and stacking for the processing raw materials. According to the mechanical structure, the paper analyzes the working principle and control strategy of each component in the loading-and-unloading material manipulator systems.
文摘In this paper, Dynamic Relaxation Method is applied to study the postbuckling path of cylindrically curved panels of laminated composite materials during loading and unloading. The phenomenon that loading paths do not coincide with unloading paths has been found. Numerical results are given for cylindrically curved cross-ply panels subjected to uniform uniaxial compression under two types of boundary conditions. The influence of the number of layers, the panels curvature and the initial imperfection on the postbuckling paths is discussed.
基金Supported by Science and Technology Research Projcect of Anhui Province(1301022052)Anhui Province Jingde Feixiang Electric Appliance Co.LtdTyto Innovation Team from HFUT
文摘In order to achieve workpiece′s automatic loading-and-unloading, this paper designs a manipulator. Use the vacuum chuck mechanism to achieve the function of reclaiming and the cylinder rails to achieve the function of pick-feeding materials. PLC control technology is applied to control system and improve the efficiency and reduce human labor.To ensure the strength,Solidworks simulation performs thestress and strain analysis to verify material strength.
基金Supported by National Natural Science Foundation of China(No.50974100)WHUT(NO.125106002)
文摘The mechanical properties are essentially different when rock material is subjected to loading or unloading conditions. In this study, loading and unloading tests with various confining pressures are conducted to investigate the mechanical properties of marble material samples taken from the deep diversion tunnels of Jinping II Hydropower Station. The stress-strain relationship, failure characteristics and strength criterion are compared and analyzed based on the experiment results. The results show： in the loading and unloading test, peak strength, lateral strain, axial strain and plastic deformation increase significantly as the confining pressure increases. Lateral strain increased significantly and obvious lateral dilatancy can be observed to the change of confining pressure; The fracture mode is mainly the single shear fracture for the triaxial compression test and post-peak test, angle between the failure surface and the ends of the rock material becomes smaller as the confining pressure increases. Hock-Brown strength criterion reflects the strength characteristics of marble material under two different unloading conditions, and has some supplementary effects to the rock material of mechanical field.
文摘煤矿井下作业环境复杂多变,钻探成为煤矿开采的必备环节。钻杆加卸是钻探过程中的重要步骤,传统的人工钻杆加卸方式不仅耗时费力,而且劳动强度极大,对工人的身体健康构成严重威胁。为了提高煤矿井下钻机的钻杆加卸效率,降低劳动强度,提升作业安全性,探讨并总结当前煤矿井下智能化钻机配套钻杆自动加卸技术,发现多轴液驱机械手式换杆技术具有高度的灵活性和适应性,可作为解决多规格钻具自动加卸问题的有效方案。基于当前机械手关键技术的研究,分析得出动态路径规划方法是多轴机械手式钻杆加卸系统研究的难点,在总结当前机械手动态轨迹规划领域研究进展的基础上,分析现有路径规划方法的优缺点,特别是在动态环境下的适应性表现。在此基础上,研究了基于快速随机搜索树(Rapidly-exploring Random Tree,RRT)算法的混合轨迹规划策略在复杂环境下的应用,展示了这些方法在提升机械手路径规划精度、减少操作时间以及增强系统鲁棒性方面展现出的显著优势。针对未来研究方向,提出了进一步提升机械手动态轨迹规划算法性能,增强机械手自主作业能力,推动煤矿井下自动化技术全面应用的建议。
