首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9篇
  完全免费   5篇
  力学   14篇
  2021年   1篇
  2014年   1篇
  2010年   2篇
  2009年   1篇
  2007年   2篇
  2006年   3篇
  2005年   1篇
  2003年   1篇
  1998年   1篇
  1996年   1篇
排序方式: 共有14条查询结果,搜索用时 109 毫秒
1.
岩土力学参数概率分布的切比雪夫多项式推断   总被引:4,自引:0,他引:4  
提出了较大样本岩土力学参数概率分布的切比雪夫多项式逼近法。基于数值逼近原理,直接根据试验样本矩,运用切比雪夫多项式推断岩土力学参数的概率密度函数,并用精度较高的K—S检验法,从理论上证明所求密度函数的正确性和实用性。该方法直接根据试验样本信息和统计方法推断,而不是事先假定成经典的理论概率分布,因此数学和物理意义更加充分。通过对各种经典分布曲线(正态分布、指数分布、对数正态分布等)数值检验,结果表明所得到的逼近表达式有很好的拟合性能。根据样本数据得出的某岩石抗压强度概率密度函数,与实际统计所得分布频率非常接近,可以满足岩土工程可靠性分析的要求。  相似文献
2.
粘弹性半空间上刚体的垂直振动   总被引:1,自引:0,他引:1  
根据弹性力学混合边值条件,建立了粘弹性半空间上刚体垂直振动的对偶积分方程,并用正交多项式化积分方程为线性代数方程组,并提出可以用围线积分和解析开拓原理把方程组系数的无穷积分化为有穷积分。计算结果与实测资料进行了比较,说明本方法是正确的。  相似文献
3.
Probability density function (PDF) of stochastic responses is a critical topic in uncertainty analysis. In this paper, orthogonal decomposition technique was extended to discuss non-stationary response of non-linear oscillator under random excitation. The PDF of stochastic reponses is represented by a set of standardized multivariable orthogonal polynomials. According to the Galerkin scheme, the original problem, which has to solve the Fokker-Planck-Kolmogorov (FPK) equation, was converted to a first-order linear ordinary differential equation, in terms of unknown time-dependent coefficients. Then, stationary and non-stationary PDFs of uncertainty responses were obtained. In numerical examples, first-order and second-order non-linear systems exposed to the Gaussian white noise were considered. Finally, the accuracy of the proposed method was demonstrated through appropriate comparisons to Monte-Carlo simulation and analytical results.  相似文献
4.
对随机高斯外激励作用下强非线性振动系统响应演变概率密度函数求解问题进行探讨.应用随机函数空间的正交分解理论,将由熵方法定义的指数形式概率密度函数表达式在随机泛函空间中展开,推导了展开级数所满足的FPK方程.运用加特金方法,将概率密度与系统状态向量共同表征的偏微分方程求解问题转化为求解逼近系数的一阶常微分方程组形式,使得问题求解成为可能.数值算例中研究了随机外激励作用下下一阶与二阶随机非线性系统响应概率密度函数求解问题,初步讨论了随机非线性系统响应概率密度函数的瞬态演化过程.  相似文献
5.
This paper presents the effect of non-homogeneity of the material of plate structures on the vibration frequencies. The non-homogeneity of the plate is characterized by taking a variety of combinations of linear as well as quadratic variations in the Young’s modulus and density of the material. Boundary characteristic orthogonal polynomials using Gram-Schmidt procedure have been employed in the Rayleigh Ritz method. The results have been included for the first few frequencies of the plate element for all the boundary conditions viz. clamped, simply supported and free. Related Tables and graphs are incorporated to show the effect of the non-homogeneity parameter on the frequencies of the vibration of elliptic and circular plates.  相似文献
6.
为了更有效地使用超声技术检测功能梯度管道中纵向缺陷,基于3维弹性理论,采用一种正交多项式法研究无限长功能梯度材料管道中的周向导波。为验证方法的正确性与适用性,首先采用该方法计算均匀各向异性管道中的周向导波,并与已有数据相比较。其次,计算了不同梯度函数下管道周向导波的频散曲线,并与均匀管道进行了比较,说明了梯度材料管道中周向导波的特点以及梯度函数变化对频散曲线的影响。最后,求解了不同径厚比下功能梯度材料圆柱壳周向导波的频散曲线,分析了径厚比的变化对频散曲线的影响。  相似文献
7.
Conventional orthogonal polynomial approach can solve the multilayered plate only when the material properties of two adjacent layers do not change significantly. This paper de- veloped an improved orthogonal polynomial approach to solve wave propagation in multilayered plates with very dissimilar material properties. Through numerical comparisons among the exact solution, the results from the conventional polynomial approach and from the improved poly- nomial approach, the validity of the improved polynomial approach is illustrated. Finally, it is shown that the conventional polynomial approach can not yield correct continuous normal stress profiles. The improved orthogonul polynomial approach has overcome this drawback.  相似文献
8.
黄斌 《计算力学学报》2010,27(2):202-206
将随机结构有限元分析的递推求解方法和伽辽金投影方法相结合,提出了求解随机静力响应的改进的递推求解方法。利用随机收敛的非正交多项式展开表示由于材料、外部荷载或构件几何尺寸的随机性导致的结构随机响应。采用递推求解方法得到响应多项式展开的初始系数,并运用定义的数学算子显式地表达出来。然后,通过定义修正系数,应用伽辽金方法对随机力平衡方程在非正交多项式基上进行投影,得到了和响应展开阶次个数相同的确定的有限元方程,并进行求解得到了修正系数。数值算例表明,通过对递推求解方法中响应表达式系数的修正,以很小的计算代价较大地提高了随机响应的计算精度;与基于正交多项式展开的随机有限元方法相比,在精度相当的前提下新方法耗费的计算时间大大降低。  相似文献
9.
To solve Fredholm integral equations of the second kind, a generalized linear functional is introduced and a new function-valued Pade-type approximation is denned. By means of the power series expansion of the solution, this method can construct an approximate solution to solve the given integral equation. On the basis of the orthogonal polynomials, two useful determinant expressions of the numerator polynomial and the denominator polynomial for Pade-type approximation are explicitly given.  相似文献
10.
To solve Fredholm integral equations of the second kind, a generalized linear functional is introduced and a new function-valued Padé-type approximation is defined. By means of the power series expansion of the solution, this method can construct an approximate solution to solve the given integral equation. On the basis of the orthogonal polynomials, two useful determinant expressions of the numerator polynomial and the denominator polynomial for Padé-type approximation are explicitly given. Project supported by the National Natural Science Foundation of China (No.10271074)  相似文献
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号