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91.
The boundary knot method (BKM) of very recent origin is an inherently meshless, integration‐free, boundary‐type, radial basis function collocation technique for the numerical discretization of general partial differential equation systems. Unlike the method of fundamental solutions, the use of non‐singular general solution in the BKM avoids the unnecessary requirement of constructing a controversial artificial boundary outside the physical domain. The purpose of this paper is to extend the BKM to solve 2D Helmholtz and convection–diffusion problems under rather complicated irregular geometry. The method is also first applied to 3D problems. Numerical experiments validate that the BKM can produce highly accurate solutions using a relatively small number of knots. For inhomogeneous cases, some inner knots are found necessary to guarantee accuracy and stability. The stability and convergence of the BKM are numerically illustrated and the completeness issue is also discussed. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
92.
The present paper is devoted to the analysis of the contact problems with Coulomb friction and large deformation between two hyperelastic bodies. One approach to separate the material nonlinearity and contact nonlinearity is presented. The total Lagrangian formulation is adopted to describe the geometrically nonlinear behavior. Nondifferentiable contact potentials are regularized by means of the augmented Lagrangian method. Numerical examples are carried out in two cases: rigid-deformable contact and deformable-deformable contact with large slips. The numerical results prove that the proposed approach is robust and efficient concerning numerical stability. 相似文献
93.
焊接方法对双相不锈钢焊接接头力学性能的影响 总被引:2,自引:0,他引:2
研究了不同焊接方法对SAF2205双相不锈钢板焊接接头金相组织和力学性能的影响,结果表明,采用不同焊接方法得到的焊接接头的铁素体与奥氏体两相比例不同,使焊接接头的力学性能存在较大差异,对实际生产中SAF2205双相不锈钢的焊接具有一定的指导意义。 相似文献
94.
孙伟成 《兵器材料科学与工程》2003,26(3):59-62
综述了纳米晶体材料和纳米碳管材料的力学性能研究的最新进展。实验数据表明纳米晶体材料的强度与其晶粒尺寸大小的关系并不遵循Hall-Petch方程。相对于常规晶体材料 ,纳米材料的超塑性发生在更低的温度和更高的应变速率下。理论计算和实验数据表明 :纳米碳管是一种有着高刚性、高强度、高韧性和低密度的材料。纳米晶体材料和纳米碳管的异常的力学性能已经有了一些应用实例 相似文献
95.
建(构)筑物机械拆除方法综述 总被引:1,自引:0,他引:1
介绍了几种常用的建(构)筑物机械拆除方法,对其工作原理、特点、应用条件及局限性加以分析和说明。 相似文献
96.
针对一类特殊而不能直接对其观察的管道(如动物的血管),为了准确了解其内部特征和形态,借助计算机给出了一种用腐蚀算法来重建管道原形的方法。这种方法简单易行,而且精确度高。 相似文献
97.
98.
Evaluation of Slow Crack Growth Resistance in Ceramics for High-Temperature Applications 总被引:1,自引:0,他引:1
The slow (subcritical) crack growth (SCG) resistance of Si3 N4 and SiC ceramics has been evaluated by a stepwise loading test on bending bars precracked by Vickers indentation. Three highly refractory materials were selected for the evaluation: i.e., (1) high-purity Si3 N4 sintered by hot isostatic pressing (HIP) without additives and (2,3) α - and β - SiC pressureless sintered with B and C addition. Under the hypothesis of linear elastic behavior at high temperature, which was found satisfied in the present materials, the SCG resistance was expressed in terms of initial stress intensity factor critical for SCG failure within a predetermined lifetime. The present method was found useful in shortening the testing time and consistent with other traditional fatigue tests (e.g., static-fatigue test): It is recommended as a screening test for materials under research and development. Among the materials tested in the present study, the highest SCG resistance up to 1440°C was found in the high-purity Si3 N4 without additives. 相似文献
99.
100.
Jaroslav Mackerle 《International Journal of Pressure Vessels and Piping》1996,69(3):279-339
The paper gives a bibliographical review of the finite element methods (FEMs) applied for the analysis of pressure vessel structures/components and piping from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore the aim of this review is to give the reader an encyclopaedic view of the differnt possibilities that exist today for the finite element analysis in the fields of pressure vessels and piping. The bibliography at the end of the paper contains approximately 1900 references to papers, conference proceedings and theses/dissertations on the subject that were published in 1976–1996. These are classified in the following categories: linear and non-linear, static and dynamic, stress and deflection analysis; stability problems; thermal problems; fracture mechanics problems; contact problems; fluid-structure interaction problems; manufacturing of pipes and tubes; welded pipes and pressure vessel components; development of special finite elements for pressure vessels and pipes; finite element software; and other topics. Also finite element software, general purpose and special purpose codes, used for the analysis of pressure vessels and pipes are briefly discussed and presented. 相似文献