Research On Influence Of Shear-Span Rate To Shear Performance Of RC Beam

Due to the variation of mechanical parameters such as stirrup,concrete elastic modulus and plastic damage,the shear resistance of the simply supported beam will decrease greatly under fire.At present,most scholars at home and abroad study the influence of beam on the flexural performance under fire,but there are a few studies on the shear performance of beams under fire.The shear span ratio is an obvious factor in influencing the shear failure of simply supported beam fire.Therefore,this study uses 15 RC simply supported beams as specimens,and it uses ABAQUS software to simulate the effect of shear span ratio on the shear behavior of beams.The main research contents are as follows:1)According to the European standard,the temperature field model of reinforced concrete beam is established by using the thermal performance parameters at high temperature.Based on the temperature field model of the built beam,the mechanical model of the reinforced concrete simply supported beam under high temperature is established,and the shear performance of the reinforced concrete simply supported beam under fire is simulated.2)By analyzing the temperature field,load displacement curve,stress-strain relationship and fire resistance of beams under high temperature,the influence of different shear span ratios on shear performance of simply supported beam under high temperature is studied.3)The ultimate shear capacity of simple supported beams at different temperatures is obtained.At high temperature,the effect of shear span ratio on the failure form of the oblique cross section of simple supported beams is also studied...