Material and geometrical nonlinear behaviour of cable-stayed bridges under static loads | |
| Author | Rah, Sung-yoon |
| Call Number | AIT Thesis no. ST-89-12 |
| Subject(s) | Dead loads (Mechanics) Bridges, Cable-stayed |
| Note | A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The geometrical and material nonlinear behaviour of three cable-stayed bridge systems under different types of static loads is investigated. The first two bridge systems are scaled reinforced concrete models consisting of one and two steel towers respectively, which have been tested at the Swiss Federal Institute of Technology in Lausanne, Switzerland. The third bridge system is the Rama IX cable-stayed bridge in Bangkok, Thailand. The scaled models have relatively thin concrete decks. The effect of deck thickness on the nonlinear load-dis placement behaviour is studied. All bridges are modelled as two-dimensional finite element systems and only in- plane loads a r e considered. Soil-structure interaction effects are disregarded a nd proportional loading is assumed. The tower and deck are modelled by beam elements and the cables by truss elements. The effect of cable sag, represented by an equivalent modulus of elasticity, is considered for Rama IX bridge. The following types of linear and nonlinear analyses are discussed: Ci) s mall displacements a nd linear -elastic material, Cii> large displacements and linear-eastic material, Ciii) small displacements and elasto-plastic material, and Ci v> large displacements and elasto-plastic material. For Rama IX bridge, which is a steel structure, only the material nonlinearity of the cables is modelled whereas for the scaled bridge models the inelastic moment-curvature relation of the deck girder and towers is also taken into account. The analysis is carried out with the computer program ANSYS. The results for different types of incrementally applied loads show that both geometric and material nonlinearities affect the response of cable-stayed bridges. In the cases studied, material nonlinearities play a greater role than geometric nonlinearities, and nonlinearities can be disregarded for service loads. The ultimate load of the bridges is reached when cable stresses reach t he yield limit. However, the experimental investigations s how that concrete failure of the deck (local failure) governs the capacity of the bridge. |
| Year | 1989 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Wireland, Martin |
| Examination Committee(s) | Gupta, Satyendra P. ;Ueda, Tamon |
| Scholarship Donor(s) | Government of Japan |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1989 |