共查询到20条相似文献,搜索用时 796 毫秒
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基于Abaqus有限元分析软件,建立全钢载重子午线轮胎有限元模型,并对其进行结构静力分析以及不同工况下的稳态分析.结果表明:轮胎充气后,主要变形发生在胎侧部位和胎冠中部,充气轮胎静负荷接地区域变形较大,且接地中心位移最大;制动与驱动工况下,轮胎的接地印痕关于接地中心呈现出不对称性,接地压力分布极不均匀;自由滚动工况下,接地印痕基本关于接地中心对称,接地压力分布较均匀,制动和驱动工况下的接地压力最大值远高于自由滚动工况;侧偏工况下,正侧偏角分别使接地区域以及出现接地压力最大值的位置向左移动. 相似文献
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研究车辆稳态回转对轮胎热-力耦合响应的影响。结果表明:车辆操纵稳定性测试前采用稳态回转暖胎时,定回转半径、不定车身侧向加速度工况下较定车身侧向加速度、不定回转半径工况下的轮胎整体温升梯度和幅值波动大;车辆稳态回转时,轮胎温度变化对车身侧向加速度波动非常敏感,左转向车辆车身侧向加速度增大与右侧轮胎分配负荷呈正相关变化,在复合侧偏侧倾作用下,能够加剧轮胎温升;暖胎引起轮胎温度的变化改变轮胎侧偏和纵滑等力学特性响应,造成非线性滑移区滞回幅值不稳定,易导致车辆操纵稳定性测试数据的重复性变差,进而对车辆动力学仿真验证和模型调整带来困难。本研究结果可为整车测试提供指导。 相似文献
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以子午线轮胎11R22.5为例,考虑轮胎变形的几何非线性、材料非线性以及轮胎与地面、轮胎与轮辋的大变形非线性接触等,并考虑复杂胎面花纹,利用ABAQUS软件建立轮胎与地面接触的三维有限元模型。对带复杂胎面花纹的子午线轮胎进行了静负荷工况、稳态滚动工况和侧偏工况的模拟,并将分析结果与光面轮胎进行了对比。结果表明,胎面花纹对轮胎滚动模拟结果有一定的影响,从而为轮胎设计提供参考。 相似文献
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基于ABAQUS软件建立225/40R18跑气保用轮胎和普通轮胎的三维有限元模型,分析标准负荷下2种轮胎在静负荷和稳态侧偏工况下的力学性能。结果表明,静负荷工况下,高应变能密度主要集中在支撑胶、带束层和冠带层端部,且在缺气状态下表现更明显,跑气保用轮胎胎肩处的接地压力大于普通轮胎,且径向刚度高于普通轮胎,缺气状态下跑气保用轮胎胎侧变形小于普通轮胎,且胎肩接地压力集中程度高;稳态侧偏工况下,在标准充气压力和缺气状态下,随着侧偏角的增大,跑气保用轮胎的接地印痕从矩形变为梯形,普通轮胎的接地印痕从矩形变为三角形。 相似文献
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Dinesh Singh J. K. Gehlawat Musti S. Rao 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1990,47(2):127-136
Oslefins and diolefins are important intermediates in the petrochemical industry and the future promises a further substantial increase in demand. While several catalysts have been formulated in the past for the abstraction of hydrogen from butenes and propylene, these catalysts are inefficient in the abstraction of first hydrogen from butane. Bismuth molybdates (β and γ-phases) containing iron oxide and supported on alumina are used as catalysts in the present investigation on the oxidative dehydrogenation of n-butane. Effects of catalyst content, temperature and oxygen: n-butane ratio on conversion and selectivity to butadiene and (C4H8 + C4H6) are studied in the following ranges of experimental conditions: β-bismuth molybdate/100 mol support I(K), 3–9; γ-bismuth molybdate/100 mol support I(K), 5-20; temperature, 400–500°C; O2: butane ratio, 0.6:1.7. 相似文献
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A viscometer used to measure the viscosity of 10 μl of a liquid, must be miniaturized down, and the liquid velocity gradient in the channel used to determine the viscosity coefficient. Two major factors that affect the liquid velocity are the mechanical forces exerted by the mechanical motors and electromagnetic forces. In this study, electrowetting on dielectric (EWOD) is adopted to drive liquids. Variously sized electrodes on a chip, and two shapes of channel are employed to measure the velocity gradient to determine the viscosity coefficient. The device is fabricated by microelectromechanical system (MEMS) technology. The dielectric layer used in EWOD has a high dielectric constant, BST (Ba0.7Sr0.3TiO3), to reduce the required applied voltage; its surface is coated with hydrophobic polymer, polytetrafluoro-ethylene (PTFE, Teflon® AF DuPont). Experimental results demonstrate that liquids can be pulled at 660 μm/s in linear channels by applying a voltage of 15 V. 相似文献
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考登钢作为一种高耐候结构钢,广泛应用于各个领域。在火力发电方面,考登钢主要应用在工作环境比较恶劣的烟气加热器和空气预热器中。考登钢表面涂搪的目的就是进一步提高其耐腐蚀性能,延长使用寿命。为了提高考登钢元件的使用寿命,对考登钢表面涂搪瓷的可行性、密着性能、瓷釉、工艺控制、质量保证等方面进行了研究。 相似文献
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In reexamining medium effects on photochemical reactions, we have emphasized those on unequilibrated excited species such as the Franck-Condon species. Despite recent advances in femtochemistry, such a discussion in molecular photochemistry is uncommon, and the problem remains challenging on account of the extremely short-lived excited species. However, in such cases, a small perturbation resulting from, for example, weak guest-host interactions could turn into a determining factor in dictating the course of a photochemical channel of deactivation. Examples of medium-directed diabatic processes have been examined with this idea in mind. A modified view on rhodopsin photoisomerization is presented along with the consideration that confinement does not necessarily lead to inhibition of reactions of the trapped substrate. 相似文献
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研究了温度和pH值对漆酶酶活以及漆酶处理纤维压制纤维板性能的影响。结果表明,pH较低、温度较高时漆酶酶活较高,压制的纤维板强度性能较好。但温度太高(60~80℃),延长加热时间,漆酶稳定性变差,酶活明显降低,压制纤维板的强度下降。 相似文献
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采用密度泛函理论(DFT)考察了丙烷在Pt(111)表面上脱氢生成丙烯的反应机理。通过在Pt(111)面上预吸附一定数量H原子模拟共吸附H对丙烷脱氢过程的影响。结果表明:H共吸附能降低丙烷及其脱氢产物的吸附能,促进丙烯脱附,有利于提高丙烯的选择性;H共吸附会导致丙烷脱氢能垒变大,降低催化剂的脱氢活性;共吸附的影响随着H覆盖率增加而增大。 相似文献