光纤-含筋混凝土复合体微观力学非线性分析

Nonlinear Analyses of Micro-mechanical Behavior of Fiber-reinforced Concrete Complex

对埋入混凝土的传感光纤而言,刚性保护构件的存在会对光纤周围的微观力学场产生扰动,从而影响光纤传感精度。考虑了刚性保护件对光纤周围应力场的扰动及不同材料界面间的摩擦接触,对光纤-含筋混凝土复合体建立模型,进行了三维非线性数值分析,模拟出复合体在裂缝开裂过程中微观应力应变状态,从理论上验证了金属保护件对光纤周围应力场的影响,尤其是保护件和光纤的间距对光纤传感精度的影响,并验证了试验中光纤传感的动态范围。

For sensing fiber embedded in concrete, the rigid protecting structure will disturb micro-mechanic filed around fiber, thus affect its measuring accuracy. In the paper, for the first time, micro-mechanical behaviors of fiber-reinforced concrete complex are investigated, and 3D nonlinear numerical analyses is perform, in which both the effect of rigid structure on fiber and the frictional contact on contact surfaces between different materials are taken into account. The microscopic stress and strain state of complex in cracking are presented, which prove the effect of protecting structure on micro-mechanic field around fiber, especially the effect of distance between protecting structure and fiber on measuring accuracy. Additionally, dynamic range of fiber in test is also proved.