加载过程中钢筋混凝土梁弯曲变形的随机分析
Stochastic Analysis of Bending Deflection for Reinforced Concrete Beam in Loading Process

摘要： 为研究钢筋混凝土梁在服役期间变形随机性的变化规律,利用蒙特卡洛抽样与钢筋混凝土非线性有限元法,建立了钢筋混凝土梁非线性变形的随机分析模型.利用该模型对经典试验梁进行受力过程弯曲变形的随机分析,并对钢筋混凝土截面配筋率进行了参数分析,结果表明:在加载过程中,梁体变形的变异性是变化的;当荷载在开裂荷载高概率区间内时,梁体变形的变异性最大;不同配筋率的梁体变形的变异性有明显差异,配筋率越低,变异性越高.随着荷载的增大,梁体变形的变异性逐渐减小;当荷载接近正常使用极限时,变异性趋于稳定,此时不同配筋率的梁体变形的变异性也基本一致.
Abstract: Combining Monte Carlo sampling with nonlinear finite element method, the random analysis model for nonlinear deflection of reinforced concrete beams was established to assess the random deflection of in-service reinforced concrete beams. Based on this model, the stochastic deflection of the classic concrete beam in loading process was simulated. Meanwhile, the parametric analysis of reinforcement ratio of concrete section was performed. The results show that the variability of deflection changes in loading process. Under the loads of high probability of cracking, the variability of deflection reaches the maximum value. Moreover, the variability of deflection is affected by the reinforcement ratio. The lower reinforcement ratio leads to the higher variability of deflection. However, with the increment of the load, the variability of deflection is reduced. Finally, when the load is close to the serviceability limit state, the variability of deflection for different reinforcement ratios becomes stable and similar