混凝土多孔砖抗折强度的数值模拟

Numerical Simulation of the Tensile Strength for Perforated Concrete Brick

目的数值模拟混凝土多孔砖的抗折强度,分析内力受力性能和破坏机理.方法采用有限元方法对混凝土多孔砖的抗折强度进行非线性数值模拟.在模拟过程中,采用William-Warnke和Sargin模型分别模拟混凝土失效面和单轴受压时应力-应变关系.对多孔砖逐步施加均布荷载,提取的裂缝图揭示了混凝土多孔砖内部裂缝的发展.结果破坏最大应力分布在错排大孔内壁附近.随着荷载增加,提取出对应的裂缝分布图,揭示了多孔砖的破坏过程.与抗折试验对比吻合.荷载-位移曲线反映了多孔砖受力特性:破坏初始阶段成线性;当曲线出现拐点进入非线性阶段;当曲线再次出现拐点时,破坏进入加速阶段,非线性特征更加明显,直至破坏.结论为多孔砖的拓扑形状设计提供了理论依据.

This paper focused on simulating flexural performance of perforated concrete brick, and the analysis of the internal force performance and failure mechanism. The finite element method was adopted to analyze the tensile strength of perforated concrete brick under bending. With the help of the model of William- Warnke and Sargin, we can simulate both failure section and stress-strain curve under uniaxial compression. Applying uniformly distributed load gradually showed the crack development. The destruction of maximum stress was distributed over the inner-wall of wrong row holes. With the increase of load, the crack distribution diagram revealed destruction process which matched the bending test. The load-displacement curve reflected the mechanical behavior. The curve appeared as the linear track in the early destruction. When taming point occurred,it entered the nonlinear stage. When turning point occurred again, it accelerated destruction to corrupt. The conclusion is significant to study the process of cracking. At the same time, it provides fundamental theory of the perforated concrete brick topology shape design.