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Numerical Simulation and Physical Simulation of Sea Wave Groups

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China Ocean Engineering 1996年第3期11卷 295-305页

作者： Yu Yuxiu and Gui ManhaiProfessor, dept. of civil Eng. Dalian University of Technology (DUT), Dalian 116024 . Master, dept. of civil Eng. DUT, Dalian, 116024 dept. of civil Eng. Dalian University of Technology Dalian 116024 dept. of civil Eng. DUT Dalian 116024

Based on field wave data, an empirical formula of wave envelope spectrum is given in this paper. Then the methods of both numerical and physical simulation of sea wave groups with the given spectrum and groupiness par... 详细信息

关键词： wave group wave envelope spectrum numerical simulation physical simulation

Durability Properties of Materials and Mixture Composition of Bitumen Stabilized Materials

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武汉理工大学学报 2010年第17期32卷 215-226页

作者： TWAGIRA M E JENKINS J K dept.of civil Engineering Stellenbosch University

Bitumen Stabilized Materials (BSMs) are widely recognized as environmentally friendly through significantly reduced energy consumption,reduced emissions and reuse of high percentage of RAP and recycled pavement materials. In order for these materials to be cost effective,their life-cycle performance needs to be proven. Durability of BSMs is a long-term phenomena that requires consideration during mix design. Time is very important variable for performance consideration under field conditions. The factors that influence durability and long-term performance of BSMs include the mineral aggregates,binder and mixture compositions. In this study,the important,but less understood aspects of durability properties of BSMs were investigated. These include wear and tear of mineral aggregates,age-hardening of binder (foamed bitumen and bitumen emulsion) and moisture susceptibility of typical mix composition. The wear and tear was investigated using Durability Mill Index (DMI) test,binder ageing was investigated for short and long-term effect,and moisture susceptibility was investigated by pulsing water pressures using new device i.e. moisture induction simulation test (MIST). The accelerated moisture conditioning simulates field conditions whereafter retained shear properties are evaluated. The results found that durability of mineral aggregates is significantly influences by the type and nature of mineral composition. The ageing of binder occurred in both short and long-term conditions,with short-term effects being dominating the foamed bitumen properties during laboratory production. Moisture susceptibility is significantly influenced by the mix compositions of aggregates blends with and without RAP,with different bitumen binder types (foamed bitumen or bitumen emulsion) and active filler type (cement or lime) and contents. The evaluation and ranking of mixes which are resistant and susceptible to moisture damage was done using retained cohesion (RC) after dry and wet monoton

关键词： durability properties bitumen stabilized materials moisture susceptibility ageing

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结构比例柔度矩阵

哈尔滨工业大学学报 2006年第8期38卷 1236-1238,1242页

作者：段忠东闫桂荣欧进萍 SPENCER B F 哈尔滨工业大学土木工程学院 dept.of civil and Environmental Engineering University of Illinois at Urbana-ChampaignUrbana62801USA

在环境激励情况下,仅通过测试结构响应不可能获得结构柔度矩阵,因此提出了比例柔度矩阵的概念,该柔度矩阵与结构真正的柔度矩阵仅相差一个比例常数.对于测试自由度完备和非完备两种情况,提出了构建结构比例柔度矩阵的方法,并证明该比例... 详细信息

在环境激励情况下,仅通过测试结构响应不可能获得结构柔度矩阵,因此提出了比例柔度矩阵的概念,该柔度矩阵与结构真正的柔度矩阵仅相差一个比例常数.对于测试自由度完备和非完备两种情况,提出了构建结构比例柔度矩阵的方法,并证明该比例常数近似为结构的第一阶模态质量.经算例验证,比例柔度矩阵的提出和应用可以将基于柔度的损伤识别方法扩展应用到环境激励或外境激励源未知的情况.

关键词：比例柔度矩阵柔度矩阵损伤定位环境激励

Virtual reality approach for 3D large model browsing on web site

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Journal of Chongqing University 2005年第3期4卷 129-133页

作者：郭葆锋 dept.of civil Engineering Ji Nan UniversityGuang Zhou 510632P.R.China Dept.of ArchitectureSouth China University of TechnologyGuang Zhou 510641P.R.China

Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator’s Garden. Translating building data to the Virtual Reality Modeling Language (VRML) is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-of- detail switching.

关键词： virtual reality 3D modeling optimization

Wenchuan Post-earthquake Reconstruction by Utilizing Composite Tubular Construction and FRP Retrofitting Technology

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四川大学学报（工程科学版） 2009年第3期41卷 231-247页

作者： ZHAO X L AL-MAHAIDI R dept. of civil Eng. Monash Univ. Clayton VIC 3800 Australia

This paper presents two possible construction methods that could be adopted in the Wenchuan post-earthquake *** is the composite tubular construction and the other is FRP(Fibre Reinforced Polymer) retrofitting *** background of these two methods,the existing research and relevance to Whenchuan post-earthquake reconstruction are described.

关键词：抗振结构建筑结构建筑物 FRP 地震重建

Aseismic Reliability Analysis Approach for Offshore Jacket Platform Structures

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China Ocean Engineering 1998年第4期13卷 375-382页

作者： Zhuang, YZ Jin, WL Zhejiang Univ Dept Civil Engn Hangzhou 310027 Peoples R China

By means of nonlinear pushover collapse analysis approach, the aseismic reliability analyses of two offshore jacket platforms in the Bohai Gulf in China are studied according to their ocean location and environmental loadings there. On the basis of those analyses, an aseismic reliability analysis approach is presented. The results show that the aseismic reliability of those platforms is high. Also it is proved that this aseismic reliability analysis approach is simple, practical and reliable.

关键词： offshore jacket platform aseismic reliability nonlinear pushover collapse analysis

COMBINED LEGENDRE SPECTRAL-FINITE ELEMENTMETHOD FOR THE TWO-DIMENSIONAL UNSTEADYNAVIER-STOKES EQUATION

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Journal of Computational Mathematics 1999年第5期17卷 495-508页

作者： Song-man He Cai-ping Yang(Department of Basic Courses, civil Aviation University of China, Tianjin 300300, China) civil Aviat Univ China Dept Basic Courses Tianjin 300300 Peoples R China

A combined Legendre spectral-finite element approximation is proposed for solving two-dimensional unsteady Navier-Stokes equation. The artificial compressibility is used. The generalized stability and convergence are ... 详细信息

关键词： Navier-Stokes equation combined Legendre spectral-finite element approximation

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Acta Mechanica Solida Sinica 1996年第2期9卷 104-123页

作者： Yonglin Xu Ted Belytschko, dept. of civil Engineering, Northwestern University, Evanston, IL 60208, U. S. A NORTHWESTERN UNIV DEPT CIVIL ENGNEVANSTONIL 60208

The Self-Similar Crack Expansion (SSCE) method is proposed to evaluate stress intensity factors at crack tips, whereby stress intensity factors of a crack can be determined by the crack opening displacement over the crack, not just by the local displacement around the crack tip. The crack expansion rate is estimated by taking advantage of the crack self-similarity. Therefore, the accuracy of the calculation is improved. The singular integrals on crack tip elements are also analyzed and are precisely evaluated in terms of a special integral analysis. Combination of these two techniques greatly increases the accuracy in estimating the stress distribution around the crack tip. A variety of two-dimensional cracks, such as subsurface cracks, edge cracks, and their interactions are calculated in terms of the self-similar expansion rate. Solutions are satisfied with errors less than 0.5% as compared with the analytical solutions. Based on the calculations of the crack interactions, a theory for crack interactions is proposed such that for a group of aligned cracks the summation of the square of SIFs at the right tips of cracks is always equal to that at the left tips of cracks. This theory was proved by the mehtod of Self-Similar Crack Expansion in this paper.

关键词： self-similar crack expansion stress intensity factor crack extension method

Assessment of nutrients and conductivity in the Wachusett Reservoir watershed:An investigation of land use contributions and trends

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International Soil and Water Conservation Research 2024年第2期12卷 337-350页

作者： Amanda Carneiro Marques Carlos Eduardo Veras Emily Kumpel John E.Tobiason Christian D.Guzman dept.of civil and Environmental Engineering University of Massachusetts AmherstMA01003USA

The quality of drinking water for the Boston Metropolitan Area,supplied by the Quabbin-Wachusett system,is impacted by environmental *** objectives of this study are to increase understanding of the role that small streams may play in degradation of reservoir quality by characterizing seasonal constituent patterns from 1998 to 2020 in the Wachusett Reservoir watershed and by developing enhanced modeling *** monitoring(1998–2012)exhibited increased loads due to increasing flows despite declining solute *** present study analyzed seasonal nitrate(NO3)and total phosphorus(TP)concentration and load trends from 2012 to 2020 across 11 *** conductivity(SC)was also assessed to evaluate the impacts of road salt *** 2012 to 2020,statistical results for mean nutrient concentrations suggest static or declining temporal trends,while SC in all tributaries exhibited increasing *** use data suggest association with altered drainage landscapes as potential sources of increased constituent *** with the highest concentrations of TP,NO3,and SC have the largest percentage of impervious and cultivated areas,two to three times greater than other *** flows were modeled using the airGR hydrological model,subsequently used to calculate ***,flow magnitude was a more important load driver than long-term nutrient concentrations,thus,showing that stream discharge controlled load *** the other hand,persistently high SC levels controlled the increasing SC load ***,many nutrient reduction management strategies demonstrated an important impact from 1998 to *** watershed programs aimed at reducing salt applications,concentrations in streams are increasing,indicating a long-term legacy of salt *** smaller tributaries represent a modest portion of the system,addressing these sources has the potential to further reduce the long-term ecological

关键词： Water quality Nutrients Road salt Long-term trends Pollutant loading