PROCEDURE FOR COMPUTING THE POSSIBILITY AND FUZZY PROBABILITY OF FAILURE OF STRUCTURES

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｉｎｉｔｉａｔｉｏｎｏｆｒｅｌｉａｂｉｌｉｔｙｔｅｃｈｎｉｑｕｅｓｗａｓｄｕｅｔｏｔｈｅｅｘｉｓｔｅｎｃｅｏｆｌａｒｇｅａｍｏｕｎｔｏｆｕｎｃｅｒｔａｉｎｔｉｅｓｉｎｅｎｇｉｎｅｅｒｉｎｇ .Ａｃｃｏｒｄｉｎｇｔｏｔｈｅｄｉｆｆｅｒｅｎｃｅｓｉｎｔｈｅｐｒｏｄｕｃｅｄｃａｕｓｅａｎｄｐｈｙｓｉｃａｌｍｅａｎｉｎｇ,ｕｎｃｅｒｔａｉｎｔｉｅｓｍａｙｂｅｄｉｖｉｄｅｄｇｅｎｅｒａｌｌｙｉｎｔｏｔｈｒｅｅｔｙｐｅｓ:ｒａｎｄｏｍｎｅｓｓ,ｆｕｚｚｉｎｅｓｓａｎｄｕｎａｓｃｅｒ…     

STABILITY MARGIN OF SYSTEMS WITH MIXED UNCERTAINTIES UNDER THE IQC DESCRIPTIONS

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｓｔｕｄｙｏｆｓｔａｂｉｌｉｔｙｒｏｂｕｓｔｎｅｓｓｉｎｔｈｅｐｒｅｓｅｎｃｅｏｆｕｎｃｅｒｔａｉｎｔｙｉｓａｎｉｍｐｏｒｔａｎｔａｓｐｅｃｔｏｆｃｏｎｔｒｏｌｓｙｓｔｅｍａｎａｌｙｓｉｓ.Ｉｔｉｓｎｅｃｅｓｓａｒｙｔｏｍｏｄｅｌｐｈｙｓｉｃａｌｓｙｓｔｅｍｓａｓｔｈｅｐｅｒｔｕｒｂｅｄｓｙｓｔｅｍａｒｏｕｎｄａｋｎｏｗｎｎｏｍｉｎａｌｓｙｓｔｅｍ .Ｕｓｕａｌｌｙｔｈｅｕｎｃｅｒｔａｉｎｔｉｅｓｉｓｃｏｍｐｏｓｅｄｏｆｐａｒａｍｅｔｒｉｃａｎｄｎｏｎ＿ｐａｒａｍｅｔ…     

Analysis of a Partially Debonded Conducting Rigid Elliptical Inclusion in a Piezoelectric Matrix

ＩｎｔｒｏｄｕｃｔｉｏｎＤｕｅｔｏｔｈｅｉｒｉｎｔｒｉｎｓｉｃｅｌｅｃｔｒｏｍｅｃｈａｎｉｃａｌｃｏｕｐｌｉｎｇｐｒｏｐｅｒｔｉｅｓ,ｐｉｅｚｏｅｌｅｃｔｒｉｃｃｅｒａｍｉｃｓｈａｖｅｂｅｅｎｅｘｔｅｎｓｉｖｅｌｙｕｓｅｄｉｎｄｅｓｉｇｎｏｆｖａｒｉｏｕｓｅｌｅｃｔｒｏｎｉｃａｎｄｅｌｅｃｔｒｏｍｅｃｈａｎｉｃａｌｄｅｖｉｃｅｓｓｕｃｈａｓｓｅｎｓｏｒｓａｎｄａｃｔｕａｔｏｒｓ.Ｉｎｒｅｃｅｎｔｙｅａｒｓ,ｍｅｃｈａｎｉｃａｌａｎａｌｙｓｉｓｏｆｄｉｓｌｏｃａｔｉｏｎｓ ,ｃｒａｃｋｓ,ｃａｖｉｔｉｅ…     

Probability of random events of inspection and repair and maintaining reliability of structures

ＩｎｔｒｏｄｕｃｔｉｏｎＦａｔｉｇｕｅｆｒａｃｔｒｕｅｉｓａｐｒｉｍａｒｙｍｏｄｅｏｆｆａｉｌｕｒｅｆｏｒｍｅｔａｌｌｉｃｓｔｒｕｃｔｕｒｅｓａｎｄｍｅｃｈａｎｉｃａｌｓｙｓｔｅｍｓｓｕｂｊｅｃｔｅｄｔｏｖａｒｉｏｕｓｄｙｎａｍｉｃｌｏａｄｓ.Ａｔｔｈｅｂｅｇｉｎｎｉｎｇｏｆｓｅｒｖｉｃｅ,ｓｏｍｅｉｎｈｅｒｅｎｔｄｅｆｅｃｔｓｓｕｃｈａｓｍｉｃｒｏｃｒａｃｋｓ,ｗｅｌｄｉｎｇｄｅｆｅｃｔｓ,ｎｏｔｃｈｅｓ,ｖｏｉｄｓｅｔｃ.ｅｘｉｓｔｉｎｍａｎｙｓｔｒｕｃｔｕｒｅｓｏｒｅｌｅｍｅｎｔｓ.Ｔｈｅｓｅｄ…     

ORIENTATION DISTRIBUTION FUNCTIONS FOR MICROSTRUCTURES OF HETEROGENEOUS MATERIALS (Ⅰ) ──DIRECTIONAL DISTRIBUTION FUNCTIONS AND IRREDUCIBLE TENSORS

ＩｎｔｒｏｄｕｃｔｉｏｎＡｎａｔｕｒａｌｏｒａｒｔｉｆｉｃｉａｌｍａｔｅｒｉａｌｉｓｕｓｕａｌｌｙｍｉｃｒｏｓｃｏｐｉｃａｌｌｙｈｅｔｅｒｏｇｅｎｅｏｕｓａｎｄｏｗｎｓａｃｅｒｔａｉｎｍｉｃｒｏｓｔｒｕｃｔｕｒｅｃｏｍｐｒｉｓｉｎｇｔｈｅｍａｔｅｒｉａｌｃｏｎｓｔｉｔｕｔｉｏｎｓ (ｃｒｙｓｔａｌｌｏｉｄ ,ｄｉｓｌｏｃａｔｉｏｎｓ ,ｐｈａｓｅｔｒａｎｓｆｏｒｍａｔｉｏｎｓ,ｍｉｃｒｏ＿ｃｒａｃｋｓ,ｖｏｉｄｓ,ｆｉｂｅｒｓ,ｉｎｃｌｕｓｉｏｎｓ) .Ｉｔｉｓｎｏｔｓｕｒｐｒｉｓｉｎｇｔｈａｔａｎｕｍｂｅ…     

UNILATERAL CONTACT PROBLEMS USING QUASI-ACTIVE SET STRATEGY

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｒｅａｒｅｏｆｔｅｎｓｏｍｅｓｔｒｕｃｔｕｒｅｓｏｒｃｏｍｐｏｎｅｎｔｓｗｈｉｃｈｃａｎｏｎｌｙｔｒａｎｓｆｅｒｏｎｅｓｐｅｃｉａｌｆｏｒｍｏｆｓｔｒｅｓｓ,ｓｕｃｈａｓｔｈｅｃａｂｌｅｗｈｉｃｈｃａｎｏｎｌｙｂｅｕｓｅｄｔｏｔｒａｎｓｆｅｒｔｈｅｔｅｎｓｉｏｎｓｔｒｅｓｓａｎｄｔｈｅｃｏｎｔａｃｔｃｏｍｐｏｎｅｎｔｗｈｉｃｈｃａｎｏｎｌｙｔｒａｎｓｆｅｒｔｈｅｐｒｅｓｓｕｒｅ.Ｉｎｇｅｎｅｒａｌ,ｓｕｃｈｐｒｏｂｌｅｍｓａｒｅｏｆｔｅｎｃａｌｌｅｄｔｈｅｕｎｉｌａｔ…     

COMPUTATION OF SUPERSONIC TURBULENT FLOWFIELD WITH TRANSVERSE INJECTION

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｍｉｘｉｎｇｆｌｏｗｆｉｅｌｄｒｅｓｕｌｔｉｎｇｆｒｏｍａｓｏｎｉｃｇａｓｅｏｕｓｉｎｊｅｃｔｉｏｎｉｎｊｅｃｔｅｄｔｒａｎｓｖｅｒｓｅｌｙｉｎｔｏａｓｕｐｅｒｓｏｎｉｃｆｒｅｅｓｔｒｅａｍｉｓｅｎｃｏｕｎｔｅｒｅｄｉｎｍａｎｙｆｉｅｌｄｓｓｕｃｈａｓｒｏｃｋｅｔｍｏｔｏｒｔｈｒｕｓｔｖｅｃｔｏｒｃｏｎｔｒｏｌｓｙｓｔｅｍｓ,ｓｕｐｅｒｓｏｎｉｃｃｏｍｂｕｓｔｉｏｎ ,ｈｉｇｈ＿ｓｐｅｅｄｆｌｉｇｈｔｖｅｈｉｃｌｅｒｅａｃｔｉｏｎｃｏｎｔｒｏｌｊｅｔｓ,ａｎｄｇａｓ＿ｔ…     

ELECTROELASTIC FIELD FOR AN IMPERMEABLE ANTI-PLANE SHEAR CRACK IN A PIEZOELECTRIC CERAMICS PLATE

ＩｎｔｒｏｄｕｃｔｉｏｎＤｕｅｔｏｔｈｅｉｎｔｒｉｎｓｉｃｃｏｕｐｌｉｎｇｃｈａｒａｃｔｅｒｉｓｔｉｃｓｂｅｔｗｅｅｎｅｌｅｃｔｒｉｃａｎｄｅｌａｓｔｉｃｂｅｈａｖｉｏｒｓ,ｔｈａｔｉｓ,ａｐｐｌｉｅｄｍｅｃｈａｎｉｃａｌｌｏａｄｉｎｇｐｒｏｄｕｃｅｓｅｌａｓｔｉｃｄｅｆｏｒｍａｔｉｏｎ ,ａｓｗｅｌｌａｓｅｌｅｃｔｒｉｃｆｉｅｌｄ ,ａｎｄｃｏｎｖｅｒｓｅｌｙｅｌｅｃｔｒｉｃｆｉｅｌｄｃａｎｇｉｖｅｒｉｓｅｔｏｅｌａｓｔｉｃｄｅｆｏｒｍａｔｉｏｎ ,ｐｉｅｚｏｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌｓｈａｖｅ…     

A MICROMECHANICS METHOD TO STUDY THE EFFECT OF DOMAIN SWITCHING ON FRACTURE BEHAVIOR OF POLYCRYSTALLINE FERROELECTRIC CERAMICS

ＩｎｔｒｏｄｕｃｔｉｏｎＲｅｃｅｎｔｌｙ ,ｔｈｅｆｅｒｒｏｅｌｅｃｔｒｉｃｃｅｒａｍｉｃｓｈａｓｓｕｃｈｅｘｃｅｌｌｅｎｔｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｐｉｅｚｏｅｌｅｃｔｒｉｃｉｔｙａｎｄｐｙｒｏｅｌｅｃｔｒｉｃｉｔｙｅｔｃ .ｔｈａｔｉｔｂｅｃｏｍｅｓｏｎｅｏｆｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｆｕｎｃｔｉｏｎａｌｍａｔｅｒｉａｌｓ.Ｆｏｒｉｎｓｔａｎｃｅ ,ｔｈｅｗｉｄｅｌｙａｐｐｌｉｅｄｓｅｎｓｏｒｓ,ｔｒａｎｓｄｕｃｅｒｓａｎｄａｃｔｕａｔｏｒｓｅｔｃ .ａｒｅｍａｄｅｏｆｔｈｅｆｅｒｒｏｅ…     

ON THE ASYMPTOTIC BEHAVIOR OF HOPFIELD NEURAL NETWORK WITH PERIODIC INPUTS

ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｎｃｅｔｈｅｓｐｅｃｉａｌｓｕｐｅｒｉｏｒｉｔｙｏｆａｒｔｉｆｉｃｉａｌｎｅｕｒａｌｎｅｔｗｏｒｋｓｔｅｃｈｎｏｌｏｇｙｉｎｖａｒｉｏｕｓｅｎｇｉｎｅｅｒｉｎｇｔｅｃｈｎｉｑｕｅｓｆｉｅｌｄｓ,ｓｕｃｈａｓｏｐｔｉｍｉｚａｔｉｏｎ ,ａｓｓｏｃｉａｔｉｖｅｍｅｍｏｒｉｅｓ,ｐａｔｔｅｒｎｒｅｃｏｇｎｉｔｉｏｎ ,ｓｉｇｎａｌｐｒｏｃｅｓｓｉｎｇａｎｄａｕｔｏｍａｔｉｃｃｏｎｔｒｏｌ,ｔｈｅｒｅｈａｓｂｅｅｎｉｎｃｒｅａｓｉｎｇｉｎｔｅｒｅｓｔｉｎｔｈｅｉｎｖｅｓｔｉｇａｔｉ…     

线性区间有限元静力控制方程的组合解法

区间有限元的静力控制方程常被归结为区间方程组来求解。但实际上两者并不等价。本文根据不确定结构有限元分析的力学背景，直接从问题的基本参量的不确定性出发，将基本区间参量的边界组合与求解区间方程组的有关解法相结合，提出了线性区间有限元静力控制方程的两种组合解法－参量边界全组合法和组合迭代法。可以以较小的计算量获得或逼近位移和应力区间的准确界限。且不受基本参量变化范围的限制。算例分析表明文中方法是实用和可行的。     

FUZZY ARITHMETIC AND SOLVING OF THE STATIC GOVERNING EQUATIONS OF FUZZY FINITE ELEMENT METHOD

The key component of finite element analysis of structures with fuzzy parameters, which is associated with handling of some fuzzy information and arithmetic relation of fuzzy variables , was the solving of the governing equations of fuzzy finite element method. Based on a given interval representation of fuzzy numbers, some arithmetic rules of fuzzy numbers and fuzzy variables were developed in terms of the properties of interval arithmetic. According to the rules and by the theory of interval finite element method, procedures for solving the static governing equations of fuzzy finite element method of structures were presented. By the proposed procedure, the possibility distributions of responses of fuzzy structures can be generated in terms of the membership functions of the input fuzzy numbers. It is shown by a numerical example that the computational burden of the presented procedures is low and easy to implement. The effectiveness and usefulness of the presented procedures are also illustrated.     

非确定结构系统区间分析的泛灰求解方法

工程中的不确定性问题可以用区间分析、概率理论或模糊理论来求解。采用泛灰区间分析法来处理结构静力分析和设计中的不确定性问题。将结构系统中的不确定性参数用区间数来表示，用有限元法建立系统的控制方程。该控制方程是线性区间方程组。然后，在概述泛灰数的概念及其运算规则的基础上，介绍了泛灰数与区间数的转化，利用泛灰数的可扩展性对区间进行分析，研究了泛灰线性方程求解，然后将它应用于结构静力分析和设计中的不确定性问题，泛灰数不仅具有区间分析的功能，而且能解决区间分析所不能解决的问题。文中给出了两个算例，列出了本文算法与其他算法的结果比较。     

Interval parameter perturbation method for evaluating the bounds on natural frequencies of structures with interval parameters

For structural parameters with uncertainties, interval mathematics can, in the case where the probabilistic distribution density of uncertain variables is unavailable, deal with the influence of uncertainties in structural parameters on the response of structures. In order to evaluate the region containing natural frequencies of structures with interval parameters, the interval parameter perturbation method is presented in this paper. The advantage of the present method is its computational efficiency in evaluating the region containing natural frequencies. A numerical example is used to illustrate the efficiency of the method proposed. The project is supported by National Youth Natural Science Foundation of China and National Outstanding Youth Science Foundation of China.     

区间可靠性分析方法及在地下隧道结构计算中的应用

基于工程结构不确定性的区间分析方法,本文将区间分析方法与可靠性分析方法相结合,探讨了一种可以获得区问可靠指标的可靠性分析方法.依据结构失效准则确定的功能函数在一定区间内变化,进而得出了可靠指标的变化区间,在得到区间可靠指标的同时也得到了一种反映结构稳健性的稳健可靠指标.结合区间有限元的优化计算方法,对某地下隧道结构进行了区间可靠性分析,所得区间可靠性指标合乎规律.     

AN INTERVAL FINITE ELEMENT METHOD BASED ON THE NEUMANN SERIES EXPANSION 1)

实际工程问题中通常存在大量的不确定参数, 区间有限元方法是一种结合有限元数值计算工具对结构进行不确定性分析的区间方法. 区间有限元的目的是获得在含有区间不确定性参数条件下的结构响应上下边界, 其关键问题在于区间平衡方程组的求解, 而这属于一类往往很难求解的NP-hard问题. 本文归纳了一类工程实际中常见的结构不确定性问题, 即可线性分解式区间有限元问题, 并针对此提出一种基于Neumann级数的区间有限元方法. 在区间有限元分析中, 当区间不确定参数表示为一组独立区间变量线性叠加时, 若结构的刚度矩阵也可表示为这些独立区间变量的线性叠加形式, 则称此类区间有限元问题为可线性分解式区间有限元问题. 对于此类问题, 采用Neumann级数对其刚度矩阵的逆矩阵进行表示, 可获得结构响应关于区间变量的显式表达式, 从而可高效求解结构响应的上下边界. 最后通过两个算例验证了本文所提方法的有效性.     

基于单元的静力区间有限元法

在许多工程问题中 ,结构参数和荷载具有某种程度的误差或不确定性。若不将它们定量化或模型化加以考虑 ,就不能作出合理的分析和设计。考虑到有限元法在科学界和工程界的广泛应用 ,本文以连续梁结构为例 ,建立了基于单元的静力区间有限元法。为了说明本方法的有效性 ,本文给出了一个数值例子 ,并把所得结果与文献 [1 2 ]进行了比较。     

Interval finite element method and its application on anti-slide stability analysis

The problem of interval correlation results in interval extension is discussed by the relationship of interval-valued functions and real-valued functions. The methods of reducing interval extension are given. Based on the ideas of the paper, the formulas of sub-interval perturbed finite element method based on the elements are given. The sub-interval amount is discussed and the approximate computation formula is given. At the same time, the computational precision is discussed and some measures of improving computational efficiency are given. Finally, based on sub-interval perturbed finite element method and anti-slide stability analysis method, the formula for computing the bounds of stability factor is given. It provides a basis for estimating and evaluating reasonably anti-slide stability of structures.     

Flexural wave bandgap properties of phononic crystal beams with interval parameters

Uncertainties are unavoidable in practical engineering, and phononic crystals are no exception. In this paper, the uncertainties are treated as the interval parameters,and an interval phononic crystal beam model is established. A perturbation-based interval finite element method(P-IFEM) and an affine-based interval finite element method(A-IFEM) are proposed to study the dynamic response of this interval phononic crystal beam, based on which an interval vibration transmission analysis can be easi...     

随机杆系结构几何非线性分析的递推求解方法

建立了随机静力作用下考虑几何非线性的随机杆系结构的随机非线性平衡方程. 将和 位移耦合的随机割线弹性模量以及随机响应量表示为非正交多项式展开式，运用传统的摄动方法获 得了关于非正交多项式展式的待定系数的确定性的递推方程. 在求解了待定系数后，利用非 正交多项式展开式和正交多项式展开式的关系矩阵，可以很方便地得到未知响应量的二阶统计矩. 两杆结构和平面桁架拱的算例结果表明，当随机量涨落较大时，递推随机有限元方法比基于 二阶泰勒展开的摄动随机有限元方法更逼近蒙特卡洛模拟结果，显示了该方法对几何非线性 随机问题求解的有效性.