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Boundary element-free method for elastodynamics

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Science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 641-657页

作者： CHENG Yumin1.& peng {1.2 1. shanghai Institute of Applied Mathematics and Mechanics, shanghai university, shanghai 200072, china 2. department of civil engineering, shanghai university, shanghai 200072, china shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China department of {1. engineering Shanghai University Shanghai China

The moving least-square approximation is discussed first. Sometimes the method can form an ill-conditioned equation system, and thus the solution cannot be obtained correctly. A Hilbert space is presented on which an orthogonal function system mixed a weight function is defined. Next the improved moving least-square approximation is discussed in detail. The improved method has higher computational efficiency and precision than the old method, and cannot form an ill-conditioned equation system. A boundary element-free method (BEFM) for elastodynamics problems is presented by combining the boundary integral equation method for elastodynamics and the improved moving least-square approximation. The boundary element-free method is a meshless method of boundary integral equation and is a direct numerical method compared with others, in which the basic unknowns are the real solutions of the nodal variables and the boundary conditions can be applied easily. The boundary element-free method has a higher computational efficiency and precision. In addition, the numerical procedure of the boundary element-free method for elastodynamics problems is presented in this paper. Finally, some numerical examples are given.

关键词： moving least-square approximation, improved moving least-square approximation, elastodynamics, boundary integral equation, meshless method, boundary element-free method, Fourier eigen transform.

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沥青路面车辙预估方法

同济大学学报（自然科学版） 2004年第11期32卷 1457-1460页

作者：彭妙娟许志鸿同济大学道路与交通工程教育部重点实验室

车辙会造成大量的经济损失 ,影响到路面行车的安全性和舒适性 ,而且还会引起路面其他形式破坏的产生和加剧 .为此总结了国内外学者对高等级道路沥青路面车辙预估的研究方法 ,并讨论了各种车辙预估方法的优缺点 ,在此基础上提出了高等级... 详细信息

车辙会造成大量的经济损失 ,影响到路面行车的安全性和舒适性 ,而且还会引起路面其他形式破坏的产生和加剧 .为此总结了国内外学者对高等级道路沥青路面车辙预估的研究方法 ,并讨论了各种车辙预估方法的优缺点 ,在此基础上提出了高等级沥青路面车辙预估的研究发展方向 ,为以后沥青路面车辙方面的研究及其沥青路面的设计提供参考 .

关键词：沥青路面车辙层应变法弹性理论粘弹性理论有限元法

Development of steel dampers for bridges to allow large displacement through a vertical free mechanism

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Earthquake engineering and engineering Vibration 2014年第3期13卷 375-388页

作者： Pan peng Yan Hong Wang Tao {1. Peizhen Xie Qiang Key Laboratory of civil {1. Safety and Durability of china Education Ministry Department of Civil Engineering Tsinghua University china {1. Architectural Design & Research Institute CO. Ltd. Key Laboratory of Earthquake engineering and engineering Vibration Institute of Engineering Mechanics China Earthquake Administration School of civil {1. Qingdao Technological University department of Building {1. Tongji University

Isolation bearings and dampers are often installed between piers and superstructures to reduce the seismic responses of bridges under large earthquakes. This paper presents a novel steel damper for bridges. The damper employs steel plates as energy dissipation components, and adopts a vertical free mechanism to achieve a large deformation capacity. Quasi-static tests using displacement-controlled cyclic loading and numerical analyses using a finite element program called ABAQUS are conducted to investigate the behavior of the damper, and a design methodology is proposed based on the tests and numerical analyses. Major conclusions obtained from this study are as follows：（1. the new dampers have stable hysteresis behavior under large displacements; （2） finite element analyses are able to simulate the behavior of the damper with satisfactory accuracy; and （3） simplified design methodology of the damper is effective.

关键词： steel damper large deformation bridge cyclic loading numerical simulation

时序InSAR用于安康膨胀土机场稳定性监测

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武汉大学学报（信息科学版） 2021年第10期46卷 1519-1528页

作者：张双成司锦钊徐永福牛玉芬樊茜佑朱武安鹏郭衍辉长安大学地质工程与测绘学院陕西西安710054 上海交通大学土木工程系上海200030 河北工程大学矿业与测绘工程学院河北邯郸056038 陕西佳维空间地理信息科技有限公司陕西安康725000

膨胀土高填方区域形变及其边坡稳定性是膨胀土灾害相关研究中的关键问题,针对安康机场填筑程度高、膨胀土分布范围大等特点导致的潜在地面形变问题,采用基于高程改正的时序合成孔径雷达干涉测量(interferometric synthetic aperture rad... 详细信息

膨胀土高填方区域形变及其边坡稳定性是膨胀土灾害相关研究中的关键问题,针对安康机场填筑程度高、膨胀土分布范围大等特点导致的潜在地面形变问题,采用基于高程改正的时序合成孔径雷达干涉测量(interferometric synthetic aperture radar, InSAR)技术获取安康机场运营前期地表形变。安康机场飞行区、航站区以及膨胀土边坡稳定影响区3类典型区域形变时序结果表明,安康机场基本稳定,累积形变量较小,区域最大形变量为-21.7 mm,机场内部最大形变量为-1..9 mm,其形变量在民用机场岩土工程设计规范标准要求范围之内。进一步结合区域降水与填方层深数据分析发现,现存微小地表形变及其特殊规律为膨胀土填方区工后沉降与膨胀土胀缩性形变的联合作用所致。

关键词：安康机场膨胀土时序InSAR 稳定性监测