排序方式: 共有10条查询结果,搜索用时 15 毫秒
1
1.
2.
3.
4.
Zhang Zhennan Ge Xiurun Li Yonghe 《Acta Mechanica Solida Sinica》2006,19(3):196-202
Only two macroscopic parameters are needed to describe the mechanical properties of linear elastic solids, i.e. the Poisson's ratio and Young's modulus. Correspondingly, there should be two microscopic parameters to determine the mechanical properties of material if the macroscopic mechanical properties of linear elastic solids are derived from the microscopic level. Enlightened by this idea, a multiscale mechanical model for material, the virtual multi-dimensional internal bonds (VMIB) model, is proposed by incorporating a shear bond into the virtual internal bond (VIB) model. By this modification, the VMIB model associates the macro mechanical properties of material with the microscopic mechanical properties of discrete structure and the corresponding relationship between micro and macro parameters is derived. The tensor quality of the energy density function, which contains coordinate vector, is mathematically proved. Prom the point of view of VMIB, the macroscopic nonlinear behaviors of material could be attributed to the evolution of virtual bond distribution density induced by the imposed deformation. With this theoretical hypothesis, as an application example, a uniaxial compressive failure of brittle material is simulated. Good agreement between the experimental results and the simulated ones is found. 相似文献
5.
基于二维弹性理论, 利用Hellinger-Reissner变分原理, 通过引入对偶变量, 推导
了双参数地基上正交各向异性梁平面应力问题的辛对偶方程组; 采用分离变量法和本征展
开方法, 将原问题归结为求解零本征值本征解和非零本征值本征解, 得到了适用于任意横纵
比的梁的解析解. 由于在求解过程中不需要事先人为地选取试函数, 而是从梁的基本方程出
发, 直接利用数学方法求出问题的解, 使得问题的求解更加合理化. 其中, 地基对梁的力学
行为的影响看作是侧边边界条件, 类似于外载, 可通过零本征解的线性展开来评价, 非零本
征值本征解对应圣维南原理覆盖的部分. 还利用哈密顿变分原理, 给出了两端固支梁的
一种新的改进边界条件. 编程计算了细梁和深梁等算例, 研究了地基上梁的变形沿着厚度方
向的变化特性, 验证了辛方法的有效性. 相似文献
6.
一种新的数值方法——无网格伽辽金法(EFGM) 总被引:78,自引:8,他引:70
无网格伽辽金法(EFGM)是近几年发展起来的与有限元相似的一种数值算法,它采用移动的最小二乘法构造形函数,从能量泛函的弱变分形式中得到控制方程,并用拉氏乘子满足本征边界条件,从而得到偏微分方程的数值解中得到该法只需节点信息,不需将节点连成单元,此外,还有精度高,后处理方便等优点,本文介绍其基本原理及实现过程,并用算例表明,该法具有一定的发展前景。 相似文献
7.
8.
9.
10.
电化学法修饰玻璃碳电极及其铜的阳极溶出伏安法测定 总被引:3,自引:0,他引:3
在邻苯二酚-甲醛-NaOH介质中,于-0.1 ̄+1.5V(vs,SCE)扫描范围内用循环伏安法制作修饰玻璃碳电极。电极可用于水中痕量铜的测定,其灵敏度比未修饰的玻璃碳电极提高35倍以上,定量下限为0.1ng/ml。 相似文献
1