Dissertation > Excellent graduate degree dissertation topics show

Study on the Three Dimensional Creep Stress on the Contact Surface of Twice-prestressed Composite Beam

Author: QianYuanShun
Tutor: LuoJianHui
School: Hunan University
Course: Structural Engineering
Keywords: High-speed railway Twice-prestressd composite beam Creep theory Stress redistribution Minimum excess principle
CLC: U441.5
Type: Master's thesis
Year: 2014
Downloads: 0
Quote: 0
Read: Download Dissertation

Abstract


As a new style of structure, twice-prestressed composite beam is one of the newstructures that the prestressed concrete technique used in the bridge structure. Thebridge used in high-speed railway have the high requirement of deformation control,ordinary prestressed concrete became of no advantage. Because of the goodperformance in crack resistance property and deformation control property, thetwice-prestressed composite beam is worth to be populared in high-speed railway.Due to the particular construction technology, the two part of concrete in thetwice-prestressed composite beam have different dead load and concrete age. Thisdifference will make the creep deformation of longitudinal fibers different. The creepdeformation of longitudinal fibers in the twice-prestressed composite beam restrictsinteractionally, this cause stress which is called stress redistribution caused byeffects of creep. In this paper, we calculate the twice-prestressed composite beam’sstress redistribution caused by effects of creep, by using the liner creep theory andaging theory as well as the the curvature changes compatibility condition, accordingto the internal force equilibrium conditions. The strain increment and the curvatureincrement also could be calculated then. By using the curve fitting theory,twice-prestressed composite beam’s creep camber formula could be obtained. Bycomparing with the experimental result, we can know the formula used to calculatethe twice-prestressed composite beam’s creep camber is feasible. By comparing theresult of the twice-prestressed composite beam and ordinary concrete beam, we canknow that the twice-prestressed composite beam could reduce the creep camber.External loads and effects of creep can cause the stress on the contact surface.Method for calculating the stress on the contact surface is composed of two: the finiteelement method and energy method. In this paper, we can take the age-adjustedmodulus replace the modulus of concrete, take the equivalent load replace the effectsof creep. Based on ANSYS, the finite element method using plane42(2D unit) andSolid65(3D unit) can calculate the contact surface creep stress. By comparing theresults, can we find that the development trend of stress and the calculation results arebasically the same. Stress on the contact surface caused by effects of creep distributeat the end part of the twice-prestressed composite beam. The main parameters ofinfection could be discussed as follows: the stress of contact surface increasing as the first step prestressing force went up, as the precast beam’s loading concrete agedecreased, as the distance between the first step prestressing force tensioning andfield-cast beam casting reduced, as annual mean humidity fell, as concrete gradediminished, as the concrete age of the second step prestressing diminished. At lastusing quadratic polynomial describe the creep stress on the contact surface, accordingto minimum excess principle, basing on the deformation compatibility, the stress onthe contact surface could be calculated.

Related Dissertations

  1. Research on the Revenue Distribution of PPP Mode about High-speed Railway Project,F283
  2. A Study on the Marketing Strategy of Shanghai-Nanjing High-speed Railway Based on Consumers’ Behavior Theories,F532
  3. Monitioring of Mechanics Properties of Geogrid-Reinforced and Pile-Supported Embankment in Chaoshan Station,TU470
  4. The Integrated Scheme of Mobile Communication System and Key Technology Research on High Speed Railway,TN929.5
  5. Research on Construction Design of Precast Splice of Simple Supported Box Girder in High-speed Railway,U445.1
  6. The Development and Application of Spray Polyurea Elastormer Waterproof Material on High-speed Railway,TQ639
  7. Study on Spatial Development Patterns and Planning Countermeasures of "high-speed Railway New Town" Along Beijing-Guangzhou High-speed Railway,TU984.113
  8. Study on Passenger Volume Analysis Model of Intercity High-Speed Railway Based on System Dynamics,U293.13
  9. Research on the Development Strategies of High-Speed Railway Station Region,TU984
  10. Studies on Railway Bridge Coupled Vibration of Train Rail-Bridge System Under the Influence of Creep,U441.3
  11. The Research of the Influence by the Materials of High-speed Railway Station Waiting Room on Sound Environment,TU112
  12. The Wireless Sensor Network Monitoring System of High-speed Railway,TP274
  13. Research on Jing-Hu High-speed Railway Landscape Environment Impact Assessment Based on GIS,X820.3
  14. High-speed railway passenger aesthetic performance evaluation studies,TU248.1
  15. Functional Layout Planning Study for Urban Core Area of High-speed Railway Station,TU984.191
  16. High - speed railway bridges mitigation and isolation,U442.55
  17. The high-speed railway bridge performance - based seismic design method,U442.55
  18. Elastoplastic seismic response analysis of high - speed railway bridges,U441.3
  19. Testing and prediction of Soft Bridge Pile Foundation Settlement,U443.15
  20. Soil - structure interaction under the vehicle - bridge Coupled Vibration Analysis System,U441.3
  21. High-speed railway steel truss girder cable-stayed bridge construction process simulation analysis and feasibility study for construction of the tower beam synchronization,U448.27

CLC: > Transportation > Road transport > Bridges and Culverts > Structural principles, structural mechanics > Stress analysis, thermal stress
© 2012 www.DissertationTopic.Net  Mobile