共查询到20条相似文献,搜索用时 468 毫秒
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曾祥华 《电网与水力发电进展》2011,27(4):71-74
主要介绍了应用大型通用有限元软件对大溪水库溢洪闸进行三维有限元静、动力分析的方法,采用更为合理的接触分析模型模拟侧向土压力作用下闸室底板与基岩的张开效应,研究探讨了闸室结构在各种工况下的变形及应力分布规律,进而了解闸室结构在设计条件下的工作形态,评价结构的安全性能,并根据三维有限元静动力分析成果优化了闸室的结构设计,使结构布置更为合理,在实际工程中取得了良好的效果。 相似文献
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在水闸闸室抗震设计中,为充分考虑闸室结构空间振动的耦联影响,建立了能反映闸室结构实际情况的空间三维计算模型,采用振型分解反应谱法对闸室结构进行了抗震动力计算,并以嶂山闸闸室为例,结合闸室结构地震作用效应的分析结果,提出了有针对性的抗震措施,达到了减小地震作用效应、增强闸室抗震性能的目的。 相似文献
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浆砌石水闸在长期运行过程中,受外界冻融作用,水泥砂浆易产生劣化效应,影响其应力变形特性和服役寿命。考虑到冻融作用对水泥砂浆力学性能的劣化效应,结合红旗渠分水闸工程,利用ABAQUS有限元软件,建立拱圈及闸室结构精细的三维有限元模型,研究了不同劣化程度下闸室的应力和变形情况。结果表明,随着劣化程度的加重,该工程闸室在拱顶附近和交通桥墩处逐渐出现应力集中,应力和变形基本呈曲线变化,且变化速率越来越大。这些部位是闸室的薄弱部位,在结构设计和安全运行监测时应给予足够重视。 相似文献
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根据初步设计布置方案,对海句峡面板堆石坝及其高趾墙的工作性态进行三维有限元计算研究,详细分析了高趾墙的变形、应力等工作性态,论证了高趾墙设计方案的合理性。 相似文献
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对黑河引水工程金盆水利枢纽泄洪洞放水塔结构用空间有限元作了三维应力分析,给出各种荷载工况下的应力及位移场,着重研究地基断层对塔体侧墙的应力和位移分析,为工程设计提供参考. 相似文献
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The purpose of this work is to numerically examine the thermal stress distributions in a high-temperature proton exchange membrane fuel cell (HT-PEMFC) based on a phosphoric acid doped polybenzimidazole (PBI) membrane. A fluid structure interaction (FSI) method is adopted to simulate the expansion/compression that arises in various components of a membrane electrode assembly (MEA) during the HT-PEMFC assembly processes, as well as during cell operations. First, three-dimensional (3-D) finite element method (FEM) simulations are conducted to predict the cell deformation during cell clamping. Then, a nonisothermal computational fluid dynamic (CFD)-based HT-PEMFC model developed in a previous study [1] is applied to the deformed cell geometry to estimate the key species and temperature distributions inside the cell. Finally, the temperature distributions obtained from these CFD simulations are employed as the input load for 3-D FEM simulations. The present numerical study provides a fundamental understanding of the stress–temperature interaction during HT-PEMFC operations and demonstrates that the coupled FEM/CFD HT-PEMFC model presented in this paper can be used as a useful tool for optimizing HT-PEMFC clamping and operating conditions. 相似文献
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Huan-Lin Zhou Yu-Shu Li Hao-Long Chen 《Numerical Heat Transfer, Part A: Applications》2017,72(8):628-641
The boundary geometry shape is identified by the finite element method (FEM) without iteration and mesh reconstruction for two-dimensional (2-D) and three-dimensional (3-D) inverse heat conduction problems. First, the direct heat conduction problem with the exact domain is solved by the FEM and the temperatures of measurement points are obtained. Then, by introducing a virtual boundary, a virtual domain is formed. By minimizing the difference between the temperatures of measurement points in the exact domain and those in the virtual domain, the temperatures of the points on the virtual boundary are calculated based on the least square error method and the Tikhonov regularization. Finally, the objective geometry shape can be estimated by the method of searching the isothermal curve or isothermal surface for 2-D or 3-D problems, respectively. In the process, no iterative calculation is needed. The proposed method has a tremendous advantage in reducing the computational time for the inverse geometry problems. Numerical examples are presented to test the validity of the proposed approach. Meanwhile, the influences of measurement noise, virtual boundary, measurement point number, and measurement point position on the boundary geometry prediction are also investigated in the examples. The solutions show that the method is accurate and efficient to identify the unknown boundary geometry configurations for 2-D and 3-D heat conduction problems. 相似文献
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CA6110/125Z型柴油机活塞三维有限元分析及结构改进 总被引:1,自引:1,他引:1
在CA6110/125Z型柴油机活塞温度场测量试验的基础上,用三维有限元法获得了此活塞的温度场和应力场。计算结果显示,活塞特别是第一道环槽温度过高是导致柴油机长时间运转后出现活塞环胶洁和活塞产生裂纹的原因。据此,对该活塞做了相应的改进设计和疲劳安全系数的计算。 相似文献
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利用Pro/Engineer软件建立了N490型柴油机机体三维模型,并对其进行合理简化,在AnsysWorkbench中对三维实体模型进行网格划分,得到有限元模型,对机体受力和载荷进行了分析和简化,分别计算了在各缸最大爆发压力工况下的应力和变形,计算结果表明:应力集中主要出现在作功气缸的机体顶面螺栓孔附近、轴承孔附近以及隔板的加强筋处,机体中间隔板和主轴承盖刚度较差,获得的结论对指导发动机机体结构改进设计具有一定的参考价值。 相似文献
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为解决双缸水平对置风冷柴油机存在的活塞环粘结问题,首先对已知温度场的同类型的TY180F发动机活塞进行了三维有限元分析,以验证数学模型的正确性;然后建立了双缸风冷柴油机的三维有限元模型,按照TY180F发动机活塞的分析过程并充分考虑风冷柴油机传热的特点确定了传热边界条件,对活塞温度场进行了有限元计算和分析。最后根据计算结果对发动机冷却系统进行了必要的改进,试验结果表明改进后的活塞能避免活塞环粘结问题的发生。 相似文献
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X6135柴油机曲轴强度的三维有限元研究 总被引:43,自引:0,他引:43
对连续梁法对X6135柴油机曲轴进行了计算,并以某一曲拐为代表用三维有限元法对应力的具体分布进行了深入研究、得出的结论可用作改善曲轴强度的参考依据。 相似文献
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《International Journal of Pressure Vessels and Piping》1999,76(2):105-112
The determination of lower bound limit load of 3-D structures is by no means an easy task, especially for complex configurations and loading systems. In our previous work, a numerical method of upper bound limit analysis for 3-D structures with multi-loading systems was proposed. This method combines FEM and mathematical programming technique in an iterative procedure. In the present article, on the basis of the nature of the iterative procedure for upper bound limit analysis, the statically admissible stress fields, which satisfies the equilibrium equation and boundary conditions, are constructed using some intermediate variables obtained by upper bound limit analysis procedure. Moreover, a mathematical programming formulation is set up for the static limit analysis of 3-D structures under multi-loading systems and a direct iterative algorithm used to determine the lower bound limit load multiplier is proposed, which depends on the static theorem of plasticity. The numerical examples are given to demonstrate the applicability of the procedure. 相似文献