The Design Method For Reinforce Concrete Frame Beam Considering The Participation Effect Of Slab Reinforcement

In order to achieve the seismic fortification target of No Collapsing in the Strong Earthquake,a criteria of Strong Column Weak Beam is recommended in the current codes.But the previous earthquake damage shows that the failure mode of Strong Column Weak Beam still haven’t achieved because of the effect of cast-in-place floor slab.It can’t be ignored that the enhancement effect of floor slab on the beam bending moment capacity.The existence of monolithic slab.It is the main reason that making frame beam ultra stronger.There is a method to consider the participation effect of slab reinforcement through the effective flange width.Combined with previous study of floor slab about the enhancement effect on the beam bending moment capacity and the developed methods,we put forward a uniform formula of the effective flange width corresponding to the 1/50 inter-story displacement angle ratio.The uniform formula considers both of beam-column node types and the axial compression ratio to be used in the OpenSEES analysis software.The paper has carried out the following studies:(1)Reference of the existing research results,the enforcement status of Strong Column Weak Beam has been discussed,and some sugesstions for the aseismic design has been proposed.(2)Three models by using different numerical simulation method are built and the calculation results using the finite element software of OpenSEES are compared with the experimental results.The finite element model considers on structure ductility,hysteretic curve,skeleton curve,stress concentration of beam and column,etc.(3)According to the characteristics of the OpenSEES,a TCL program script file about the effective flange width of beam has been written which considers both of beam-column node types and the axial compression ratio.Building a series of RC stucture models which different in axial compression ratio and comparing these calculation results with other scholar’s numerical simulation results.The resultsindicates that using the uniform formula of effective flange width to analyze bending effect at beam-end is reasonable.(4)Using the uniform formula of effective flange width to analyze the failure models of a five layer space of RC frame structure.There are some difference influence parameters considered about the structural displacement response,the distribution of displacement angle,the plastic hinges appeared in beams and columns,etc.