Trefftz法中的自锁现象及变量减缩法

用Trefftz型边界解法分析了中厚板弯曲问题,发现了一类新的、因Trefftz函数溢机引起的“自锁现象”,并提出了一种消除这类自锁问题的“变量减缩法”。     

结构-外流体动力相互作用的半解析方法

本文采用二维解析和一维离散的方法处理无限流体介质,建立了一种分析结构与外流体动力相互作用问题的半解析无限元法,使结构与流体的耦合振动以及波浪对弹性结构绕流等三维问题化为一维问题来求解,从而在很大程度上节省了单元、内存与计算工作量,同时径向无限域边界可得以正确模拟,比现有的有限边界人工处理更显优越,文中建立了适于不同结构类型的环单元与锥单元,给出了算例与比较。     

剪切流中表面重力波的四阶Zakharov方程及其应用

当二维剪切流沿垂向线性变化时,剪切流中的二维重力波仍满足无旋条件.本文首先推导了线性剪切流中二维表面重力波的三阶和四阶Zakharov方程,它也适用于无剪切流的三维重力表面波场.用Zakharov方程研究了剪切流中波列的第一类不稳定性问题,给出了不稳定判别式,详细讨论了剪切流对不稳定区域和增长率的影响,得到了由于流的存在而出现的新的不稳定区.     

梁式结构与连续介质的相互作用分析

本文探讨适合于结构—基础—土体耦联分析的一种计算方法。提出了一种连续介质地基上的结构半解析元模型,研究了结构—介质、结构—介质—结构耦合系统的静动态特性。     

A semi-analytical method for structure-internal liquid interaction problems

A composite structure-internal liquid element is proposed in this paper. Through the use of analytical functions in two orthogonal directions, the three-dimensional problem of coupled structure-internal liquid vibration is reduced to a one-dimensional one, resulting in a drastic reduction in computing efforts.Cylindrical and conical frastum composite elements are proposed to suit different problems, and examples are presented to demonstrate the accuracy of the method.     

曲线坐标系中的分片检验条件——列式和应用

卡氏直角坐标系中的常应力分片检验条件已经得到广泛地研究,但这类条件和列式并不适用于曲线坐标系.本文建立了分片检验条件在曲线坐标中的一般形式和在正交曲线坐标中的物理分量形式.具体到轴对称问题,给出了分片检验的轴对称列式,用来构造非协调的轴对称有限元.并提出了解决伪剪应力问题的新方法.     

A SEMI-ANALYTICAL METHOD FOR STRUCTURE-INTERNAL LIQUID INTERACTION PROBLEMS

A composite structure-internal liquid element is proposed in this paper.Through theuse of analytical functions in two orthogonal directions.the three-dimensional problem ofcoupled structure-internal liquid vibration is reduced to a one-dimensional one.resulting ina drastic reduction in computing efforts.Cylindrical and conical frustum composite elements are propased to suit differentproblems.and examples are presented to demonstrate the accuracy of the method.     

Analytical,numerical and experimental investigations of architectural sandwich panels

Architectural sandwich panels with thin-walled cold-formed steel facings and rigid foamed insulating core are becoming more and more popular as enclosures for system buildings. In this paper, the structural behavior, including flexural stresses/deflections, flexural wrinkling, axial stability, thermal stresses and vibration, is presented, summarizing more than a decade of research. Methods used are analytical (boundaryvalued approaches), numerical (finite-strip, finite-layer, finite prism approaches) and experimental (full-scale testings). Key equations are formulated, and results by different methods are compared.     

ANALYTICAL,NUMERICAL AND EXPERIMENTAL INVESTIGATIONS OF ARCHITECTURAL SANDWICH PANELS

Architectural sandwich panels with thin-walled cold-formed steel facings and rigidfoamed insulating core are becoming more and more popular as enclosures for systembuildings. In this paper, the structural behavior, including flexural stresses/deflections,flexural wrinkling, axial stability, thermal stresses and vibration, is presented,summarizing more than a decade of research. Methoda used are analytical (boundary-valued approaches), numerical (finite-strip. finite-layer,finite prism approaches) andexperimental (full-scale testings). Key equations are formulated and results by differentmethods are compared.     

结构与介质分析的半解析元法

结构与介质分析是力学学科中极为主要的一个方面。这一古老学科经近百年来的发展已经成、为各自然科学中在数学上较为完整、严密和系统的一门科学,至今基本理论已相当成熟。但由于数学方法上的困难,许多问题特别是一些高维问题能得到精确解析解的范围还是有限的。但是近二、三十年来计算技术发展,特别是有限元法的提出与应用已使结构与介质分析问题的求解达到一个飞跃。目前只要确立基本方程,原则上任何这方面问题都能用有限元法来加以求解。有限元法之所以得到如此迅速发展和被广泛应用,一方面是其解决问题的能力高,另一方面也在于便于掌握。因为用有限元法解决实际问题,只需有关人员了解问题的基本关系式和共同的计算技术,而不需要一般技术人员难于掌握的比较复杂的应用数学知识。有限元法发展到现在(虽然时间不长),已经渗透到力学及其它自然科学各个领域中。但随着应用的广泛深入,有些问题也越 ...