Papers by Keyword: Negative Moment Region

Abstract: To investigate the flexural bearing capacity in negative moment region of composite beams，we examined different ends constraint components. The modeling of the beam ends connected framework has been done by the finite element software ANSYS. The concrete thickness, slab reinforcement ratio and different component at the edge of the composite framework in the negative moment region are taken into account. The performance during the process of deformation and failure are got by nonlinear analysis. The flexural bearing capacity was reported, with the negative moment region of the composite frame beam, it revealed great differences when the beams are different component. Simulation results show that the concrete thickness take the biggest influence on bearing capacity. The results showed the behaviors of the composite frame beams are different with positive moment region, and calculation based on current code for design of steel structure (GB50017-2003) would be a big deviation.

Abstract: For I-girder with high strength steel, it is known that the flexural ductility is considerably decreased by increasing the yield strength of material. Thus, it is necessary to conduct a study for guaranteeing proper flexural ductility of I-girder with high-strength steel. In this study, the evaluation of flexural ductility of negative moment region of I-girder with high strength steel where yield stress of steel is 690Mpa is presented based on the results of finite element analysis and experiment. From the results, it is found that the flexural ductility of the I-girder is significantly reduced due to the increase of elastic deformation and the decrease of plastic deformation ability of the material when the yield strength increases. This study proposed equation predicted flexural ductility of high strength steel in negative moment region. It is also proposed the method to improve the flexural ductility by an unequal installation of cross beam and an optimal position of cross beam. Finally, the effects of the unequal installation of cross beam on the flexural ductility are discussed based on the finite element results and the experimental results.