#### DEVELOPMENT OF ANALYTICAL TOOLS TO SIMULATE HYSTERESIS RESPONSE OF

PRESTRESSED PRECAST CONCRETE BEAMS

MEE14618

Suppachai SINTHAWORN

Supervisor: Susumu KONO

Country: Thailand

Damage of reinforced concrete structures during earthquakes is one of major engineering problem. Better understanding of behavior of reinforced concrete members such as load carrying capacity-drift relation is absolutely necessary. Fiber model using FORTRAN coding was developed, in order to simulate hysteresis response and backbone curves of prestressed concrete beams with T and rectangular cross sections. Effect of confining, plastic hinge length, tensile strength of concrete, cyclic rule of constitutive models were investigated. The results reveal that confining effect should be considered whereas tensile strength of concrete can be neglected in order to predict the envelop curves. The developed fiber model (FORTRAN algorithm) is capable to simulate a maximum capacity of the unbonded post-tensioned beams with a good accuracy and capture quite well lateral load - drift angle relationships (backbone curve and hysteresis loops) of beams with T and rectangular cross-sections. In addition, the proposed simple cyclic stress-strain relations of concrete (author 01 model) simulated the cyclic behavior and backbone curve of prestressed concrete beams whereas the author 03‘s model (with crack closure model) well simulated the residual drift angle. However, further calibration should be performed with more experiment data.