塔宝效应在求缺口应力集中系数中的应用

用普通云纹法研究微小弹性变形时,存在着灵敏度较低的问题.本方利用塔宝效应,产生一个不同栅线距的栅.与原栅形成初始云纹,来增加云纹条纹的密度,从而提高了测量精确度.     

氧化镁晶须的研究进展

氧化镁晶须作为一种高科技材料,其用途广泛,市场潜力巨大。详细总结了近年来国内外对于氧化镁晶须的研究进展,并指出了各种制备方法的优缺点。     

Synchronized nonpharmaceutical interventions for the control of COVID-19

Nonlinear Dynamics - The world is experiencing an ongoing pandemic of coronavirus disease-2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In...     

A higher-order boundary element method for three-dimensional potential problems

A method of eliminating the singularities involved in boundary element methods for three-dimensional potential problems is presented and the non-singular expressions of integrals on an element on which the singular point is situated are given for linear and quadratic interpolation functions. Numerical examples are compared with analytical solutions to show that the higher-order interpolations have better precision.     

A boundary element method and spectral analysis model for small‐amplitude viscous fluid sloshing in couple with structural vibrations

A boundary element method (BEM) is presented for the coupled motion analysis of structural vibrations with small‐amplitude fluid sloshing in two‐dimensional space. The linearized Navier–Stokes equations are considered in the frequency domain and transformed into a Laplace equation and a Helmholtz equation with pure imaginary constant. An appropriate fundamental solution for the Helmholtz equation is provided. The conditions of zero stress are imposed on the free surface, and non‐slip conditions of fluid particles are imposed on the walls of the container. For rigid motion models, the expressions for added mass and added damping to the structural motion equations are obtained. Numerical examples are presented. Copyright © 2000 John Wiley & Sons, Ltd.     

流体晃动时域双协边界元法分析

利用双协边界元法在时域内对流体晃动问题进行分析,推导出边界积分方程及相应的边界条件。分析过程中考虑流体的粘性,自由面上的动力学条件为法向正应力和切向剪应力为零。固壁面上采用流体质点与固壁质点速度相等的条件。时域的离散采用差分法,并利用时间步迭代,逐步追踪流体自由面,在流体的不断变动的边界上考虑其边界条件。数值结果表明本文的双协边界元法是可行的。