钢筋混凝土拱结构破坏过程中损伤场的分布与演化

采用损伤力学理论,研究了钢筋混凝土拱结构静荷载作用下损伤破坏的过程。混凝土材料是一种拟弹脆性材料,其损伤破坏过程可近似看成是弹性损伤问题。基于弹性损伤普遍理论,取其3阶近似形式,得到一个含有4个独立参数的损伤本构模型。在该损伤本构模型中,引入了一个拉压修正系数,用于描述混凝土材料在受拉与受压状态下损伤行为的不同。对一实桥中钢筋混凝土拱肋的损伤破坏过程进行了数值模拟计算,理论结果与试验结果相一致,说明本方法可较好地描述钢筋混凝土拱结构的损伤与破坏行为。

Distribution and Evolution of Damage Field for a Reinforced Concrete Arch Structure in Its Failure Process

The damage and failure problem of a reinforced concrete structure under static loading is discussed based on the continuum damage theory.The concrete is a quasi-brittle material that can be treated as the elastic damage problem.A damage constitutive model with four independent parameters is derived from the three-order form of the elastic damage theory that is established on the second law of thermodynamics.A tension-compression parameter is introduced into the damage constitutive model,for example,it can describe the different damage behaviors of concrete under tension and compression conditions.An arch rib was removed from an old bridge.The failure experiment was performed.The failure process was simulated numerically using FEM.The theoretical predictions are consistent well with the experimental results.It indicates that the proposed damage model can be applied to describe the damage behaviors of the reinforced concrete arch structures.