不同纤维长度的混杂钢纤维混凝土本构模型

Constitutive Model of Hybrid Steel Fiber Reinforced Concrete with Different Fiber Lengths

摘要:

为了充分发挥不同长度纤维的桥接作用，在混凝土基体中加入不同长度的混杂钢纤维，构成混杂钢纤维混凝土.考虑混凝土开裂后钢纤维的脱黏全过程，利用黏结-滑移模型来模拟混杂钢纤维的增强作用，建立了混杂钢纤维应力与裂缝宽度的关系.考虑到长、短钢纤维随裂缝扩展的黏结状态不同，将混杂钢纤维的增强作用分为3个阶段.基于经典的弥散开裂本构模型，将混杂钢纤维桥接作用视为应力增强，建立混杂钢纤维混凝土本构模型.将所提出的混杂钢纤维混凝土本构模型引入有限元软件Abaqus中，建立了混杂钢纤维混凝土四点弯曲试验有限元模型.通过比较试验数据与数值模拟结果，验证了所提出本构模型的正确性.

Abstract:

To fully play the role of reinforcement of fibers with different lengths， the hybrid steel fiber reinforced concrete（HySFRC） was composed of the concrete matrix and steel fibers of different lengths. Considering the fiber debonding process after cracking， the reinforcements of hybrid steel fibers were calculated by the bond-slip model， and the relationship between steel fiber stress and crack width was established. For the debonding state of hybrid steel fibers along with the crack propagation， the reinforcements of hybrid steel fibers were divided into three stages. Based on the classic smear crack of constitutive model， the bridging effect of hybrid steel fibers was thought to be enhancement， and the constitutive model of HySFRC was established. The constitutive model of HySFRC was introduced into Abaqus software， and the finite element model was established for the four-point bending test of HySFRC. The correctness of the proposed constitutive model was verified by comparing the experimental date with numerical simulated data.