To truly reflect the spatial constraint effects of the structure on the frame beam,the axial constraint stiffness index was proposed to quantify the spatial constraint effect of the structure and a numerical model was established to simulate the spatial constraint effects of the frame structure.Comparing with the test data of the full-scale frame structure shows that the bending capacity of the frame beam calculated according to the specifications has a relative error ranging from 42％to 75％,but after considering the axial constraint effects of the structure,the relative error is reduced to less than 25％,which shows that the model can simulate the axial constraint effect of the frame structure and verifies the rationality and reliability of the numerical model.The equivalent elastic model was established in the finite element software SAP2000.By single-parameter analysis,the key variables that have significant influence on the axial constraint stiffness of RC frame beams were found out.These key variables were fully arranged and combined within the value range of common projects,and large-scale numerical analysis was carried out to analyze the mechanism of structural space constraints and the distribution law of axial constraint stiffness of RC frame beams under the limit state,and the calculation method of axial constraint stiffness of RC frame beams under the limit state was obtained.
维普
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