基于弹性应变能的钢筋混凝土简支梁极限承载力判据研究

Ultimate bearing capacity criterion of reinforced concrete beam based on elastic strain energy

基于弹性应变能提出了钢筋混凝土简支梁极限承载力的能量判别依据。首先对简支梁进行了有限元建模计算;然后对简支梁9种工况下的混凝土单元弹性应变能进行了概率统计分析,由加载过程中弹性应变能的概率分布形式及变化情况来分析混凝土单元的破坏,从整体趋势上计算极限承载力,降低了数值计算时的误差。研究发现:混凝土单元应变能符合对数正态分布,且随着加载过程逐渐趋于稳定,较客观地反映了构件变形过程中能量积累的特征;应变能对数正态分布拟合参数的变化较符合二次曲线,由二次曲线方程能够推断出构件所能承受的极限荷载,与理论值相比有较高的一致性,其误差为13.6%,且此误差可通过改进模型得到控制。文中所提的判据可为极限承载力判据的研究提供参考。

Since the deformation and destruction of materials are closely related to energy changes,it is of greater application value to study the failure of concrete materials from the perspective of energy.An energy criterion of the ultimate bearing capacity of reinforced concrete beam based on the elastic strain energy is put forward in this paper.First,the finite element numerical analysis software is used to establish the calculation model of reinforcedconcrete beam and the elastic strain energies of concrete element under 9 conditions are statistically analyzed.Then the probability distribution and the change of the strain energy in the loading process are analyzed to study the failure of the concrete element,the ultimate bearing capacity of the beam calculated from the overall distribution trend can reduce the error in numerical calculation.The results show that the strain energy of concrete element can meet the Lognormal distribution and finally it has the property of stabilizing,this property of data reflects more accurately the characteristics of energy accumulation in the deformation process.The variation of fitting parameters of the lognormal distribution of strain energy is more consistent with the quadratic curve,and we can infer the ultimate load that the component can withstand from the quadratic curve equation,and compared with the theoretical value,the established ultimate bearing capacity criterion has a certain credibility,it provides references for the research of ultimate bearing capacity.