查询词典 boundary element method

The results show that a sound bonded interface is obtained without sheet inclusion, pore and unbinding. The microstructure consists of bulk α-Mg phase and needle compound in the weld metal, element Al diffuses along the grain boundary of the substrate into the welding line. A little Y diffuses into the base metal. A little Mn and Cu segregate and element Ni distributes homogeneously and no segregation appears in weld area.

结果表明：界面接合良好，未观察到片状夹杂物、气孔及未焊合等缺陷；焊缝区由块状α-Mg相和针状化合物组成，基体中的Al元素通过晶界扩散偏聚到焊缝中，微量Y元素扩散到基体中，有少量的Mn和Cu元素发生偏聚，Ni元素分布均匀，没有发生偏聚现象。

Considering the loading and boundary conditions of the model finite element calculation is carried out. Both for the working conditions of prestress and load, the finite element model of the box beam is approved to be suitable and correct by the actual test results.

考虑模型的载荷及约束进行有限元计算，在预应力和载荷两种工况下，利用实测结果论证了箱型梁的有限元分析模型是合适和准确的。

The main research tasks and results are as follows:(1) Through comparing the stress intensity factor of compact tension specimen calculated by finite element software with the theoretical value, the feasibility of calculating fracture parameters of crack tip in ABAQUS software was verified.(2) The relationship between the elastic modulus of the material and research scale was studied based on deriving the cohesive stress theory and other relevant theories. And the elastic modulus of the material on meso-scale was determined.(3) Global model and sub-model of the finite element were built in th...e macro-scale, and stress-strain field nearby the crack tip was analyzed, and the results show that the detailed stress-strain in the crack tip could be obtained by using the sub-model technique.(4) In meso-scale, the crack growth model was also established by assuming the crack propagating along the grain boundary, and the detailed stress-strain field in the crack tip was obtained.(5) The effect of crack length on Von Mises stress, and maximum principal stress and strain was analyzed in meso-scale when equivalent KI equals 30MPa.m1/2. And the results show that except for crack tip area, the stress-strain distribution in whole specimen is not affected.

主要完成研究内容和取得成果如下：(1)利用有限元软件计算出紧凑拉伸试样的裂纹尖端应力强度因子KI值，其结果与理论值一致，从而验证了利用ABAQUS计算裂纹尖端相关断裂参量的可行性；(2)在研究内聚应力等相关理论的基础上，推导出了研究尺度与材料弹性模量的近似关系，并确定了介观尺度上的弹性模量；(3)在宏观尺度上建立了全局有限元计算模型和子模型，得到了裂纹尖端应力应变场分布，结果表明利用子模型技术获得比较准确的裂纹尖端应力应变场分布是可行的；(4)在介观尺度上利用平均晶粒尺度的方式建立了裂纹沿晶扩展模型，得到了裂纹尖端断裂过程区的微观应力应变场；(5)当应力强度因子为30MPa.m1/2时，分析了介观尺度上在裂纹沿晶扩展过程中裂纹长度对Mises应力、最大主应力和应变的影响，结果表明，裂纹扩展长度对试样整体应力应变分布影响不大，而对裂纹尖端区域有较大影响；(6)介。。。

This paper analyses three-dimensional stress distributions of the stud anchor chain by the theory of finite element and boundary element.

本文应用三维边界元法和三维有限元法对有挡锚链进行了三维应力分析，并将其结果与电测实验数据作了比较，吻合得很好。

The works in the project just done can be summarized as five respects.(1) A device was designed to fabricate the asymmetrical resonant cavities by a pendant drop. A series ARCs with variable parameters provides a valuable experimental method for investigating the characteristics of ARCs.(2) The relationship between the number of active modes and the shape parameters in an ARC was investigated. The experimental lasing threshold was compared with theoretical result, the good agreement between two shown that it was the decrease of the number of active modes in an ARC that decreased lasing threshold.(3) Dye lasing gain was used to enhance the signals of stimulated Raman scattering of the weak gain Raman modes in a circular cavity made by a pendant drop, the instantaneous SRS spectra of weak gain Raman modes in ethanol was obtained by this new method.(4) The SRS signals of minority compound in a binary chemical complex was obtained by using dye lasing gain method. The detection concentration of minority compound was reduced to an order compared with normal SRS method.(5) A cylindrical circular cavity was formed by a liquid jet, which was used to reduce the pump intensity required for laser induced plasma spectroscopy. The limit of detection of trace element in aqueous sample was greatly decreased by this new method.

我们设计并成功制作了使悬垂液滴连续变形的装置，用此装置可以方便地改变非圆对称谐振腔的几何参数，为ARCs的研究提供了一种有效的实验方法；研究了ARCs中活性模式数和变形参数间的变化规律，激光阈值的数值计算结果和激光辐射的实验结果作了比较，二者吻合的曲线说明ARCs中活性模式数量的减少是受激辐射放大阈值降低的原因；在由单元化合物构成的微型圆对称谐振腔中，首次尝试用"激光增益"增强弱增益拉曼模式的受激拉曼散射信号，获得了乙醇分子中弱增益拉曼模式的瞬态SRS光谱；在由二元混合物构成的微型圆对称谐振腔中，用染料的激光增益增强了少量化合物的SRS信号，把少量化合物的SRS信号探测浓度降低了近一个数量级，在SRS应用于瞬态过程的组份分析方面做了卓有成效的探索；用石英毛细管形成的稳定液拄构成拄形谐振腔，降低了激光诱导等离子体光谱需要的激励能量，有效地降低了水相样品的痕量元素分析极限，为LIPS应用于微量元素的化学分析开拓了一条新的技术路线。

Meshless method is a kind of method with good prospection, it can deal with many problems which can not be resolved by traditional method (finite element method, finite difference method).

无网格法是一种前景广阔的方法，能够解决许多其他传统方法（如有限元方法、有限差分法等）所不能解决的问题。

The mathematics model and the method of numecial simulation can be analysised, using the boundary element method.

采用边界元方法分析了船舶腐蚀防护的数学模型及数值模拟的方法。

A variant of the usual boundary element method,called theboundary contour method,has been proposed in recent years.

边界轮廓法是刚刚出现的一种新型的边界元法，该方法的核心是利用边界积分方程。。。

The boundary element method is used to verify the correctness of the present analytic method.

与单个的淹没矩形体相比，双淹没矩形体在一定范围内有较高的反射系数。

A direct method is implemented for computing the free-term coefficient and the Cauchy principal value integral in the higher-order boundary element method for potential flow.

采用直接数值计算方法计算了势流问题高阶边界元方法中的自由项系数和柯西主值积分，建立了波浪与结构物作用的一种高阶边界元方法。

The statistical analysis of this large set of mutations has led us to propose a diagnostic strategy that should help with the molecular work-up of optic neuropathies.

这一大系列基因突变的统计学分析引导我们提出一个诊断策略，可以帮助我们对视神经病变进行分子学的诊断检查。

The results show that the pipe grouting changes the mechanical parameters of surrounding rocks to achieve the security of engineering objectives by reinforcing surrounding rocks and bolcking the water.

研究表明：小导管注浆一方面改变了围岩的力学参数，另一方面利用浆液的固结特性可以实现堵水和加固围岩的工程目标，使隧道在开挖过程中的安全得到保障。