Nonlinear finite element analysis of composite steel-concrete cantilever beams with external prestressing

Composite steel-concrete beams prestressed with high strength external tendons have demonstrated many advantages like, increase in the ultimate moment capacity of the structure, enlarge the range of elastic behavior before yielding for the structure with the introduction of internal stresses. The stresses can oppose the moment generated by the loading. The amount of structural steel used in construction, based on yield strength alone, can be significantly reduced by the use of high-strength tendons, thereby reducing the cost of construction. In this thesis, a nonlinear finite element model for the analysis of cantilever composite steel-concrete beam with external prestressing of different tendon profiles was developed. The numerical analysis was conducted by the finite element software ANSYS. The results from finite element analysis is verified by experimental reference test result and good agreement is achieved. The thesis focuses on the effect of different tendon profiles on the flexural behavior of cantilever composite steel-concrete beam with external prestressing. Five models with different tendon profiles are straight top profile, straight bottom profile, one-point draped down profile, two-point draped down profile and two-point draped top profile. Failure loads, deflections, and load versus deflection relationships for all models are examined and it is seen that the beam with straight top profile shows the highest performance