期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
Plastic Mechanism of Multi-pass Double-roller Clamping Spinning for Arc-shaped Surface Flange 被引量:3
1
作者 FAN Shuqin ZHAO Shengdun +1 位作者 ZHANG Qi LI Yongyi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第6期1127-1137,共11页
Compared with the conventional single-roller spinning process, the double-roller clamping spinning(DRCS) process can effectively prevent the sheet metal surface wrinkling and improve the the production efficiency an... Compared with the conventional single-roller spinning process, the double-roller clamping spinning(DRCS) process can effectively prevent the sheet metal surface wrinkling and improve the the production efficiency and the shape precision of final spun part. Based on ABAQUS/Explicit nonlinear finite element software, the finite element model of the multi-pass DRCS for the sheet metal is established, and the material model, the contact definition, the mesh generation, the loading trajectory and other key technical problems are solved. The simulations on the multi-pass DRCS of the ordinary Q235A steel cylindrical part with the arc-shaped surface flange are carried out. The effects of number of spinning passes on the production efficiency, the spinning moment, the shape error of the workpiece, and the wall thickness distribution of the final part are obtained. It is indicated definitely that with the increase of the number of spinning passes the geometrical precision of the spun part increases while the production efficiency reduces. Moreover, the variations of the spinning forces and the distributions of the stresses, strains, wall thickness during the multi-pass DRCS process are revealed. It is indicated that during the DRCS process the radical force is the largest, and the whole deformation area shows the tangential tensile strain and the radial compressive strain, while the thickness strain changes along the generatrix directions from the compressive strain on the outer edge of the flange to the tensile strain on the inner edge of the flange. Based on the G-CNC6135 NC lathe, the three-axis linkage computer-controlled experimental device for DRCS which is driven by the AC servo motor is developed. And then using the experimental device, the Q235A cylindrical parts with the arc-shape surface flange are formed by the DRCS. The simulation results of spun parts have good consistency with the experimental results, which verifies the feasibility of DRCS process and the reliability of the finite element model for DRCS. 展开更多
关键词 SPINNING double-roller clamping MULTI-PASS arc-shaped surface
下载PDF
Design and experiment of anti-adhesion rototiller based on staggered double-roller scraping
2
作者 Jian Cheng Junfang Xia +3 位作者 Kan Zheng Guoyang Liu Youshuai Wei Juan Zou 《International Journal of Agricultural and Biological Engineering》 SCIE 2024年第4期165-175,共11页
In order to solve the serious problem of soil adhering blade roller in the middle and lower reaches of Yangtze River,the anti-adhesion rototiller based on staggered double-roller scraping(ARSDS)was designed by mechani... In order to solve the serious problem of soil adhering blade roller in the middle and lower reaches of Yangtze River,the anti-adhesion rototiller based on staggered double-roller scraping(ARSDS)was designed by mechanical scraping methods.The volume equation for scraping the soil adhesion part with staggered rotary blades was constructed.The mechanical conditions for separation of soil adhesion part from blade roller were clarified,and the contact time between rotary blade and soil during rotary tillage was analyzed.By this way,the key parameters affecting soil adhering on and separating from the blade roller were determined,which were rotational speed,cutting pitch and tillage depth.The spatial and temporal trajectory changes for the sidelong section edge of staggered rotary blades were analyzed,so that the rotary blade arrangement was obtained.Combining the discrete element method,selecting the soil adhesion mass on the staggered blade rollers as the response value established prediction model by Box-Behnken design test.For example,taking the tillage depth of 14 cm for wheat cultivation in the middle and lower reaches of Yangtze River,the optimal combination of parameters was determined to be 230 r/min and 10 cm for rotational speed and cutting pitch,respectively.At this time,the soil adhesion mass was 4566.67 g.In the meantime,the process of soil particles adhering staggered blade rollers and rotary blades scraping off the adhering soil were clarified.Field experiments have shown that the operation quality of ARSDS met the requirements of rototiller performance indexes.In the rice stubble field of high water moisture,the soil adhesion mass was 13.455 kg and 38.215 kg for ARSDS and conventional rototiller,respectively,which indicated that ARSDS effectively reducing soil adhesion mass.The research results can provide technical support for the design of rototiller reducing soil adhesion in the agricultural areas of the middle and lower reaches of the Yangtze River. 展开更多
关键词 rice stubble field rotary tillage reducing soil adhesion staggered double-roller discrete element method
原文传递
Study on Nanocrystalline Rare Earth Mg-Based System Hydrogen Storage Alloys with AB_3-Type 被引量:7
3
作者 唐仁衡 卢其云 +2 位作者 肖方明 彭能 王英 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第z2期343-346,共4页
A sort of rare earth Mg-based system hydrogen storage alloys with AB3-type was prepared by double-roller rapid quenching method. The alloys were nanocrystalline multi-phase structures composed of LaNi3 phase and LaNi5... A sort of rare earth Mg-based system hydrogen storage alloys with AB3-type was prepared by double-roller rapid quenching method. The alloys were nanocrystalline multi-phase structures composed of LaNi3 phase and LaNi5 phase by X-ray diffraction and scanning electron microscopy analyses, and the suitable absorption/desorption plateau was revealed by the measurement of P-C-I curve. Electrochemical studies indicate that the alloys exhibit good electrochemical properties such as high capacity and stable cycle life, and the discharge capacity is 369 mAh·g-1 at 0.2 C (72 mA·g-1). after 460 cycles, the capacity decay was only 19.4% at 2 C (720 mA·g-1). 展开更多
关键词 NANOCRYSTALLINE double-roller rapid quenching rare earth Mg-based compounds hydrogen storage alloy
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部