共查询到17条相似文献,搜索用时 250 毫秒
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推土板的仿生分形设计 总被引:4,自引:0,他引:4
大量的仿生几何非光滑触土部件减粘降阻的试验研究结果表明,触土部件表面上的几何非光滑结构单元的分布对其减粘降阻效果具有显著的影响[1]。该文利用蜣螂体表几何非光滑结构单元(GUSU)分布的生物信息,进行了推土板仿生分形设计并对所设计的推土板进行了推土试验。利用试验优化设计技术,初步考察了推土板上几何非光滑结构单元的分布对推土阻力的影响 相似文献
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安全驾驶室翻车保护结构的有限元分析 总被引:2,自引:0,他引:2
车辆驾驶室在翻车时受到巨大的冲击载荷,其翻车保护结构应具有足够的侧向刚度来阻止其变形,同时又要能够吸收一定的能量.以某矿用自卸车翻车保护结构为例,采用弹塑性理论和有限元非线性分析方法,建立了翻车保护结构的非线性有限元模型,对模型进行侧向、竖向和纵向载荷的逐次加载分析,结果表明:翻车保护结构上横梁的端点已进入塑性变形状态,能量吸收达到国际标准规定的要求,翻车保护结构的构件未侵入变形限制量(DLV). 相似文献
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Prior studies at Purdue University have shown that PTO entanglements occur most frequently on portable grain augers. A research project was conducted to measure operator exposure to PTO components and document work patterns during the use of grain augers. Information on the methodologies used to measure operator exposure is presented along with data on exposure to conventional grain augers while unloading from trucks and wagons, extended dump hopper augers, and swing-away hopper augers. It was found that operators had a higher exposure time to operating PTO components when the driveline was located on the right side of the grain auger, as one stands facing the hopper end of the auger, than on the left side of the grain auger when using conventional grain augers and grain trucks. It was determined that this added exposure was due to the position of the driver's door of the truck, the natural path of the driver from the operator's seat to the rear of the truck, and the movement of the truck body into the workspace when tilted. Of all scenarios examined, operators had the highest exposure time when using conventional grain augers and gravity-flow grain wagons. Operators had no recorded exposure time when operating swing-away hopper augers. Recommendations were made based on the observations of this study for reducing operator exposure through increased awareness of hazards and reconfiguration of the way augers are incorporated into grain handling operations. 相似文献
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电驱动铰接式工程车辆操纵稳定性控制分析 总被引:1,自引:1,他引:0
铰接式工程车辆因其铰接转向机构布置,使整车行驶过程中的横向稳定性降低。该文针对电驱动铰接式车辆的结构特点,建立了三自由度整车行驶动态数学模型,利用其各轮可独立控制的特性,提出基于直接横摆力矩(direct yaw-moment control,DYC)的车辆稳定性控制策略。分别以前车体质心侧偏角和横摆角速度、后车体质心侧偏角和横摆角速度为控制变量,建立了2种基于不同控制变量下的铰接式车辆最优直接横摆力矩控制策略。通过对地下35t铰接式自卸车的瞬态响应进行仿真分析,从响应速度、精确性等方面,探讨了2种控制策略下铰接式车辆稳定性的实现与性能。该研究可为电驱动铰接式车辆的稳定性控制提供有益的参考。 相似文献
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表土回覆是露天煤矿排土场生态修复的关键步骤,覆土厚度直接影响植物生长和复垦成本,为研究露天煤矿排土场不同覆土厚度对土壤水分入渗及植物水分利用的影响,采用室内土柱模拟试验,设置10,20,30,40,50 cm共5个覆土厚度,分别进行垂直入渗试验和室内盆栽试验(玉米),并结合氢氧同位素稳定示踪技术,研究不同覆土厚度土壤入渗和玉米水分利用特征,筛选研究区排土场最佳覆土厚度。结果表明:覆土厚度为10~30 cm(27.05~33.02 mm/min)的初始入渗速率显著高于40~50 cm(21.59~24.89 mm/min)的初始入渗速率(p<0.05),稳定入渗速率随覆土厚度的增加而增大,当覆土厚度高于40 cm后,随着覆土厚度的增加稳定入渗速率维持在3 mm/min左右。矸石层入渗过程受覆土层的影响较大,覆土厚度高于40 cm后,矸石层入渗速率基本稳定在土层连接面的入渗速率上。不同覆土厚度下玉米木质部水氢氧同位素值与土壤水氢氧同位素随土层变化曲线交点主要集中在覆土层,因此,玉米生长水分主要来源于覆土层。覆土厚度越大,2条线交点增多、交点分布范围增大,玉米对土壤水分的利用范围越大,... 相似文献