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Comparison and finite element analysis.of Steel or Synthetic Fiber Reinforced Precast, Prestressed Beams

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Journal of Civil Engineering and Architecture 2015年第9期9卷 1054-1059页

作者： Gábor Kovács Károly Páter Juhász Botond Madaras ASA Construction Ltd. Budapest 1-1-1136 Hungary Department of Mechanics Materials and Structures Budapest University of Technology and Economist Budapest H-113 5 Hungary EMI-TüV SüD Ltd. Budapest H-1043 Hungary

Usage of fiber reinforced concrete to replace shear reinforcement has become more common in the precast industry in recent years. In some cases, the use of steel fibers could be problematic because of corrosion, hence, synthetic material could be a suitable alternative material solution. Thus, it would appear logical to undertake a comparison of these fibers＇ load bearing capacity to determine suitability in each case. In this paper, the bending and the shear tests of four large-scale and prestressed beams made of steel or synthetic fiber reinforced concrete without stirrups are presented. The post-cracking residual tensile strength diagram of the fibers, according to RILEM （International Union of Laboratories and Experts in Construction Materials, Systems and Structures） TC162, is given and the experimental behavior of the fiber solutions is compared. The modified fracture energy method is used to define an advanced material model for the fiber reinforced concrete in the finite element analysis. The numerical calculations and the test results are compared in terms of crack propagation and the loading-deflect＇ion process. As a consequence, both steel and synthetic fibers seem to be good alternatives to replace the stirrups. However, the behavior of each fiber is not the same. The numerical calculation provided a good approximation for the real scale tests.

关键词： Synthetic fiber steel fiber prestress precast finite element analysis.

Nonlinear finite element analysis.of CFT-to-Bracing Connections Subjected to Axial Compressive Forces

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Nonlinear Finite Element Analysis of CFT-to-Bracing Connecti...

Thermoelastoplastic Deformation analysis.of Electromechanical Equipments under Electrocaloric Shock

2009年度海峡两岸工程力学研讨会

作者： Hsuan-Teh Hu Department of Civil Engineering National Cheng Kung University

The Abaqus finite element program together with nonlinear material constitutive models for concrete-filled tube(CFT) and steel gusset plate are used to analyze the behaviors of the gusset plate type CFT-to-Bracing connections subjected to axial compressive *** is found that the failure of CFT-to-Bracing connections occurs below the connecting *** buckling of the steel tube might take place in the areas close to the gusset plate and the fixed *** ultimate strengths of the CFT columns slightly increase with the increasing of the load ratio and the thickness of the gusset *** introduction of the cutouts on the gusset plates slightly increases the ultimate strength of the CFT column and causes more local buckling modes on the CFT columns under its ultimate strength.

关键词： concrete-filled tube bracing axial force finite element analysis.

来源： cnki会议评论

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Journal of Donghua University(English Edition) 2006年第1期23卷 42-48页

作者：于建国吕晨亮叶庆泰 640th Institute School of Mechanical Engineering Shanghai Jiaotong UniversityShanghai 200030

A coupled thermomechanical model is presented to investigate the thermoelastoplastic deformation mechanism of electromechanical equipments under the condition of electrocaloric shock. In the coupling model, differentiating from the previous analyzing viewpoint that looked upon deformation work as additional heat source, temperature-field equation is established by considering the weakening role of deformation work on the intensity of internal heat source; in the process of setting up displacement-field equation, G-derivative of nonlinear functional is introduced into the traditional theory of elastoplastic finite deformation to simplify the expression of structural stiffness; stress-field equation is constructed by using the least square method to improve the stress solution obtained by constitutive equation. The presented model is converted into finite element program to simulate deforming process of 3-D structures with temperature-dependent material properties. As an example, thermal deformation analysis.of Shanghai metro cars’ brake resistor is performed and compared with experimental results for illustrating the validity of the presented model.

关键词： electromechanical equipments electro caloric shock thermomechanical coupling finite element analysis.

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Reinforcing a Dangerous Rock Mass Using the Flexible Network Method

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Journal of China University of Geosciences 2005年第4期16卷 354-358页

作者： Yang Wendong Xie Quanmin Xia Yuanyou Li Xinping Institute of Civil Engineering ＆ Architecture Wuhan University of Technology Wuhan 430070 China

Because the main failure type of a dangerous rock mass is collapse, the treatment of such a mass should focus on controlling collapse failure. When treating dangerous rock masses, disturbing the mass （e. g. by blasting） needs to be avoided, as this new damage could cause collapse. So the self-bearing capacity of the mountain mass must be used to treat the dangerous rock mass. This article is based on a practical example of the control of a dangerous rock mass at Banyan Mountain, Huangshi, Hubei Province. On the basis of an analysis.of damage mechanism and the stability of the dangerous rock mass, a flexible network reinforcement method was designed to prevent the collapse of the rock mass. The deformations of section Ⅱ w of the dangerous rock mass before and after the flexible network reinforcement were calculated using the two-dimensional finite element method. The results show that the maximum deformation reduced by 55 % after the application of the flexible network reinforcement, from 45.99 to 20.75 ram, which demonstrates that the flexible network method is effective, and can provide some scientific basis for the treatment of dangerous rock masses.

关键词： dangerous rock mass flexible network reinforcement method finite element analysis.

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Study on Input-Output Model of Compliant Precise Micro-Location Spatial Stage

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Journal of Shanghai University(English Edition) 2002年第1期6卷 85-91页

作者：谢先海廖道训 School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan China

A precise micro location compliant stage with elastics supported system is employed for investigations. The general motion of stage supported by elastic structure is described. The analyses of forward displacement and inverse displacement of stage are formulated. The study of input output behavior of compliant mechanisms actually belongs to a stress strain field problem. By using finite element analysis. the compliance coefficients of the stage supported by ring are calculated. Finally, a case is investigated to exemplify these formulae.

关键词： compliant mechanism micro location elastic deflection finite element analysis.

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TWO METHODS OF SOLVING DYNAMIC RESPONSE BY DISCRETIZATION OF GURTIN VARIATIONAL PRINCIPLE

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Acta Mechanica Sinica 1985年第2期1卷 171-183页

作者： Zhang Ruqing Dong Ming Department of Mechanical Engineering, Chongqing University Department of Mechanical Engineering Chongqing University Chongqing China

Based on the Gurtin variational principle and the finite element method two recurrenceformulae of solving dynamic response are derived in this paper. The first recurrence formula which isconditionally stable is obtained by adopting "dual temporal finite element" to discretize the Gurtinvariational principle and then making use of convolution, while the second, an unconditionally stableone derived by discritizing the variational principle in each time step and taking appropriateintegration parameter θ.

关键词： variational principle structural dynamics computer mechanics finite element analysis.

Monitoring the Technical Condition of Dams of Hydroelectric Power Plants with an Automated Monitoring and Earthquake Registration System

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Journal of Energy and Power Engineering 2014年第8期8卷 1468-1474页

作者： Alexander Kuzmenko Daria Korolenko Evgeniy Zolotukhin Information System Laboratory Design Technological Institute of Digital Techniques Siberian Branch of the Russian Academy ofSciences Novosibirsk 630090 Russia

An approach is described that has been developed for auxiliary monitoring of technical condition of hydropower plant dams. It is based on analysis.of changes in dynamic characteristics of dams obtained by an automated monitoring and earthquake registration system that records microseismic vibrations of structures. The configuration of the system as well as the results of seismometric monitoring of the dam of Krasnoyarsk hydroelectric power plant are described. To study behavior of the dam under normal and extreme loads it was proposed to develop a model of the dam with the use of the finite element method.

关键词： Seismometric monitoring earthquake detection dynamic characteristics of dams microseismic vibrations finite element analysis.

Impact Noise of Non-homogeneous Floors： analysis.of Different Input Parameters for Computational Modeling Predictions

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Journal of Civil Engineering and Architecture 2017年第3期11卷 274-281页

作者： Maria Fernanda de Oliveira Jorge Vicoso Patricio2 Technological Institute onCivil Construction - itt Performance Unisinos University Sao Leopoldo 93022-750 Brazil National Laboratory for Civil Engineering-LNEC Lisbon1700-066 Portugal

Floor systems with non-homogeneous slabs have more complex means of propagation than homogeneous systems, with more variables to be considered in predictions by theoretical models. For those slabs, it is necessary to understand the differences of each material composing each subsystem, and the connection types between the elements of each one of this subsystem. Some floors integrating lightweight elements without structural purposes, are broadly used in several countries in precast slabs. The predictions based on computer modelling for building systems can be influenced by the input parameters related to connections between the elements of the floor system. In building structures, the analysis.of radiation due to element vibrations may be represented by wave propagation relationships as a one-dimensional system, a two-dimensional system or a three-dimensional solid. In these floors, the modelling of the interaction between elements can be basically a face, a line or a point connection. In addition, the choice of the connection type can determine the vibration transmission amongst all the floor elements. This study focuses on the differences that can be obtained in the induced vibration response due to an impact source on non-homogeneous slabs. It also presents some examples of modelling options for several floor systems, considering input parameters for different connection types.

关键词： Non-homogeneous floors vibrational response finite element analysis.

Comparative analysis.of Bridges with AASHTO and Florida I-Beam Girders

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Journal of Civil Engineering and Architecture 2014年第2期8卷 151-159页

作者： Peng Keke Fikret Necati Catbas School of Environment & Civil Engineering and Architecture Foshan University Foshan 528000 China Civil Environmental and Construction Engineering Department University of Central Florida Orlando FL 32816 USA

A comparative study of two pre-stressed girder bridges, one with AASHTO （American Association of State Highway and Transportation Officials） Type III girders and the other with new FIB （Florida l-beam） girders, is presented. FIB girders are expected to provide increased lateral stiffness, higher load carrying capacity, cost-efficiency and better reliability. In this paper, the first bridge that is analyzed is a 3-span bridge designed with six AASHTO Type III girders, and the second bridge has four FIB girders with the same span length, width and girder depth. The bridges are analyzed for Florida state legal loads SU4 and C5. Both bridges are analyzed using a sophisticated finite element method. The deflections, moment envelopes, section capacity and live load rating of the two bridges are obtained and compared. FIB girders have higher vertical stiffness, higher section capacity providing higher load rating than the AASHTO girders.

关键词： Florida I-beam girders AASHTO Type IIl girders deflection capacity load rating finite element analysis.