共查询到16条相似文献,搜索用时 171 毫秒
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沥青混凝土铺装桥面产生的高温会在箱梁内引起温差分布,导致温度变形,从而产生温度应力。目前,我国规范未对高温沥青摊铺引起的桥梁结构的温度场分布作出规定,故由其引起的温度应力在设计中尚未考虑。本文在借鉴国内外箱梁温度应力理论与方法的基础上,利用了ANSYS软件建立预应力钢筋混凝土连续梁桥三维实体模型,分别计算日照温度场、高温沥青摊铺温度场和设计活荷载下桥梁的应力状态。通过对比分析,研究了在实桥模型下,日照温度场和高温沥青摊铺温度场所引起的桥梁应力异同。 相似文献
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汽车轮胎结构非线性有限元分析 总被引:3,自引:1,他引:3
本文综述了轮胎力学的发展历史与现状,阐明了轮胎结构分析的几各主要方法、研究内容及其优缺点,并重点介绍了在子午三维非线性有限元结构分析方面的工作,包括轮胎的充气,竖直加载、稳态滚动、滚动阻力及温度场分析,给出了相应的算例。由于采用一些新的方法和技术,考虑了更真实的轮胎材料模型,结构和载荷,使得分析更为有效、精确,分析结果可作为轮胎的设计,试验与改进的依据。 相似文献
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基于FL U EN T软件模拟了轮胎滑水产生过程,并计算了不同轮胎花纹、不同车速及不同水膜厚度等条件下轮胎所受动水压强的大小。模拟分析结果表明:①复合花纹轮胎最不易发生滑水,横向花纹次之,纵向花纹最易滑水;②当水膜厚度不变时,同一轮胎所受动水压强随车速的增加而增加,且增长速度随着车速的增加而增加;③当车速不变时,同一轮胎所受动水压强随水膜厚度的增加而增加。以动水压强等于轮胎内部压强时轮胎发生滑水为判断标准,建立了轮胎临界滑水速度与水膜厚度的关系,并根据已有水膜厚度方程,推算出了临界滑水速度与降水量的关系。 相似文献
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采用网络拓扑法,求解单相串励电动机电枢三维稳态温度场分布,对电枢绕组的等效导热系数作了具体的分析计算;对电动机电枢散热的边界条件进行了妥善的处理,最后得到一个适合于计算单相串励电动机电枢温度场的计算程序,并对1050W单相串励电动机(平均)温升试验数据进行了验证,计算值与实测值基本吻合。 相似文献
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滚动轮胎的稳态热分析 总被引:1,自引:1,他引:1
本文对滚动轮胎的热平衡状态,建立了合理的数学及物理模型,用有限元法对9.00-20尼龙胎进行了模拟计算,得出轮胎内部的温度分布,并对几种不同工况下缓冲层的温度进行了讨论。 相似文献
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Wei Liang Jure Medanic Roland Ruhl 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2008,46(3):197-227
Modeling of tire friction is one of the central problems for vehicle control systems design. LuGre-type dynamic tire model has been proposed and well discussed in previous studies, because it offers a compact form of dynamic model that is convenient in advanced control studies. It has been successfully used in tire slip control design and vehicle state estimation problems. In this article, a concept of time-constrained Stribeck effect is introduced to interpret the mechanism of the LuGre friction model in predicting tire friction characteristics. A modified two-dimensional (2D) dynamic LuGre friction model is introduced to make it compatible with the governing theorem in the steady state. An analytical 2D modified LuGre-type dynamic tire model is developed, in which some fundamental limitations of classical LuGre models are eliminated. The main modifications involve a change in the structure of the 2D LuGre friction model, introduction of load-dependent parameters in 1D and 2D tire models, and a changed structure in the distributed parameter model. The proposed model is compared, in the steady state, to both the Magic Formula and the classical LuGre model. It improves model accuracy in the steady state and gives a physically reasonable distribution of the bristle deflection. A first-order lumped parameter (LP) nonlinear model, which has simpler structure than the distributed parameter model and the classical LP LuGre model, is then derived. Numerical simulations show that the proposed LP model has a good estimation for tire transient dynamics. Thus, the proposed model retains the merits of LuGre-type models and improves the agreement with observation and experimental data on friction force distribution along the patch and on the steady-state friction prediction. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(3):197-227
Modeling of tire friction is one of the central problems for vehicle control systems design. LuGre-type dynamic tire model has been proposed and well discussed in previous studies, because it offers a compact form of dynamic model that is convenient in advanced control studies. It has been successfully used in tire slip control design and vehicle state estimation problems. In this article, a concept of time-constrained Stribeck effect is introduced to interpret the mechanism of the LuGre friction model in predicting tire friction characteristics. A modified two-dimensional (2D) dynamic LuGre friction model is introduced to make it compatible with the governing theorem in the steady state. An analytical 2D modified LuGre-type dynamic tire model is developed, in which some fundamental limitations of classical LuGre models are eliminated. The main modifications involve a change in the structure of the 2D LuGre friction model, introduction of load-dependent parameters in 1D and 2D tire models, and a changed structure in the distributed parameter model. The proposed model is compared, in the steady state, to both the Magic Formula and the classical LuGre model. It improves model accuracy in the steady state and gives a physically reasonable distribution of the bristle deflection. A first-order lumped parameter (LP) nonlinear model, which has simpler structure than the distributed parameter model and the classical LP LuGre model, is then derived. Numerical simulations show that the proposed LP model has a good estimation for tire transient dynamics. Thus, the proposed model retains the merits of LuGre-type models and improves the agreement with observation and experimental data on friction force distribution along the patch and on the steady-state friction prediction. 相似文献
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轮胎在水平路面上的自由滚动接触分析 总被引:2,自引:0,他引:2
利用轮胎的模态参数直接对轮胎在水平路面上的滚动建立了便于解析计算的仿真模型。该模型可模拟轮胎稳态的滚动过程并可计算出不小同工况下的滚动特性、有效滚动半径、载荷与下沉量的关系以及印迹内变形和分布力。计算结果揭示了以往模型难以描述的微观现象,与以往文献的试验研究结果定性一致,充分显示了模型的合理性。 相似文献