岩体热-力耦合过程的数值模拟

为了更好的研究岩体在温度作用下的力学变化过程,以热力学与热弹塑理论为基础,给出了连续岩体热-力非完全耦合的控制方程。以ANSYS有限元软件为平台,基于Mohr-Coulomb破坏准则,针对高放废物处置库9种不同间距与深度的设计方案,进行了热力耦合过程的二维数值模拟。根据获得的温度、应力、位移变化曲线,确定方案2为最佳方案,可以为类似工程的建立提供参考。     

基于有限元法的双衬层危险废物填埋场高压直流电渗漏检测

According to the structural characteristics of hazardous waste landfill,a new model based on the finite element method(FEM)is developed.The detection layer is considered as a sealed space and it is assumed that total current flows through the leak for the high resistivity of geomembrane liner.The leak current is regarded as a positive point current I and the other current source is-I.Electrical potential of an arbitrary point in detection layer satisfies Poisson equation. Experiments for detecting leaks in liner were carried out.Excellent agreement between experimental data and simulated model data validates the new model.Parametric curves for a single leak show that with optimum selection of field survey parameters leaks can be detected effectively.For multiple leaks,the simulated results indicate that they are detectable when leak separation is larger than measurement spacing.     

Neural network method for solving elastoplastic finite element problems

INTRODUCTION An Artificial Neural Network (ANN) is an in-formation-processing paradigm that is inspired by the way biological nervous systems, such as the brain, process information. It is composed of a large number of highly interconnected processing elements (neu-rons) working in unison to solve specific problems. In recent years, neural network has been widely applied in the field of engineering construction as a large dimensional nonlinear dynamic system, because of its support for …     

浅谈无梁楼盖计算方法及软件应用

为了满足城市的发展,越来越多的地下车库和地下商业街等建筑开工建设,无粱楼盖结构体系具有在保证房屋净高的前提下,有效降低房屋层高的优点,结合实例,介绍了利用PKPM的SATWE、SLABCAD等模块,对无梁楼盖进行结构分析和计算的过程,并指出了软件运用过程中值得注意的要点。     

复杂边界油藏渗流压力分布的有限元法模拟

建立了单相渗流问题的有限元方程。分别对内外边界定压,内边界定压、外边界封闭,内边界定流量、外边界定压等情况下,考虑射孔影响的圆形油藏地层的渗流问题进行了数值模拟,给出了圆形油藏地层在各种情况下的单相渗流流体压力分布规律。结果表明,复杂混合边界条件下圆形油藏在射孔孔眼周边产生复杂的流体压力分布曲线,流体压力分布曲线随射孔方位和角度的不同而不同,同时表明,有限元法用于求解复杂边界条件下的渗流问题很有效。     

预处理的BiCGSTAB算法及其在涡流求解中的应用(英文)

针对涡流场有限元分析形成的大型稀疏复线性方程组,提出了预处理稳定双共轭梯度法(PBiCGSTAB).利用二维正交链表结构实现系数矩阵的全稀疏存储,采用无填充的不完全LU分解对方程组进行预处理以降低系数矩阵的条件数.将稳定双共轭梯度法从实数领域扩展到复数领域,并利用它求解预优过的复线性方程组.基于有限元法和PBiCGSTAB算法编制直线电机性能分析软件,并对一电机堵转的情况进行仿真,将计算结果和ANSYS计算出的结果进行了比较,证明了该软件的正确性.并且通过求解器比较发现,在相同精度条件下PBiCGSTAB算法只需要BiCG算法三分之一的迭代步数,证明了该算法的快速性.     

加筋土挡墙稳定性分析的数值模拟

加筋土挡墙由于其结构轻巧、便于施工、造价低而被迅速推广应用.结合330kV金州变工程加筋土挡墙的稳定性分析建立计算机仿真模型,采用普通圆弧法和假设破裂面法运用极限平衡法及有限元法进行分析.计算结果表明本文提出的数值模拟方法在一定程度上较好的反映了筋带与土体的关系,方便计算加筋土稳定性.     

本科土建专业有限元法教学探讨

有限元法是一门理论与实际紧密联系的课程,由于要求学习者具备扎实的工程数学功底,目前本科生开设《有限元法》存在着一定难度。本科有限元法教学中要采用启发性教学等多种教学方法,利用有限元软件,加强与实际工程的紧密结合,使学生真正理解有限元方法,提高学生的综合应用能力,同时把握教学内容的难度和深度,采用多种考核方式,以培养学生能力为主。     

Calculations of plastic collapse load of pressure vessel using FEA

This paper proposes a theoretical method using finite element analysis （FEA） to calculate the plastic collapse loads of pressure vessels under internal pressure, and compares the analytical methods according to three criteria stated in the ASME Boiler Pressure Vessel Code. First, a finite element technique using the arc-length algorithm and the restart analysis is developed to conduct the plastic collapse analysis of vessels, which includes the material and geometry non-linear properties of vessels. Second, as the mechanical properties of vessels are assumed to be elastic-perfectly plastic, the limit load analysis is performed by employing the Newton-Raphson algorithm, while the limit pressure of vessels is obtained by the twice-elastic-slope method and the tangent intersection method respectively to avoid excessive deformation. Finally, the elastic stress analysis under working pressure is conducted and the stress strength of vessels is checked by sorting the stress results. The results are compared with those obtained by experiments and other existing models. This work provides a reference for the selection of the failure criteria and the calculation of the plastic collapse load.     

有限元法在注胶密封腔应力分析中的应用

由于操作频繁,注胶密封腔材料强度是否满足要求,密封腔壁厚设计是否合理,将直接影响到该装置的寿命。所以通过有限元分析来优选注胶密封腔材料及结构参数,就显得非常必要。