钢筋混凝土纤维强化塑料复合梁的弯曲失效线弹性断裂力学模型

钢筋混凝土梁的受拉部位粘贴纤维强化塑料(FRP，fiber reinforced plastic)板，可以提高整个结构的承载能力．随着载荷加大，在弯矩比较大的弯曲段经常出现钢筋层与FRP板之间的层间开裂和失效．建立了多层复合梁的层间裂纹分析模型，并对其失效行为进行分析．在线弹性断裂力学(LEFM，linearelastic fracture mechanics)范畴内，应力强度因子和能量释放率(或裂纹扩展力)是两个重要参量．提出了拉伸弯曲组合梁的能量释放率的计算方法，通过弯曲平面假设研究了复合梁的变形与受力特点，计算和讨论了裂纹在不同位置时的能量释放率。

Linear elastic fracture mechanics model of bending failure of composite reinforced concrete beam with fiber reinforced plastic

The fiber reinforced plastic (FRP) can be used to strengthen reinforced concrete beam by attaching the FRP plate to tension surface of composite beam. With load increasing, the delaminating crack or failure is often appeared on the position having more moment. A model of delaminating crack of bending composite beam is established for analyging beam's failure behavior. In the scope of linear elastic fracture mechanics (LEFM), the stress intensity factor and the energy release rate (or crack extension force) G are important character factors. An approach is presented for the calculating G value for composite beam with bending and tension loading. The deformation and mechanics character of composite beam are investigated through the plane supposition of beam cross section. The calculation result of G while crack exists different positions and the related discussion are also given.