基于“梁段”跨中FRP-混凝土界面剪应力数值计算  

Calculating Intermediate Interfacial Shear Stress of FRP Strengthened RC Beams Based on Beam Segment Model

作　　者：杨奇飞[1] 陆小华[1] 熊光晶[1] 

机构地区：[1]汕头大学,汕头515063

出　　处：《应用力学学报》2009年第3期485-489,共5页Chinese Journal of Applied Mechanics

基　　金：国家科技支撑计划(2006BAJ03A07);广东省自然科学基金(5008283)

摘　　要：纤维复合材料(FRP)加固混凝土梁跨中可能发生剥离破坏,研究者已提出几种计算FRP-混凝土粘结界面剪应力τ的方法,但所得结果有较大的差异。本文先通过典型的FRP-混凝土界面的粘结-滑移本构关系和FRP加固梁实验结果,评估既有计算方法存在的问题。进而提出一个简单的"梁段"有限元计算模型,并证实其合理性和可靠性。再用此模型计算讨论了多种参数影响下的FRP-混凝土界面剪应力τ分布特征。基于实验研究和有限元计算结果,指出FRP-混凝土界面剪应力最大值τu不适合作为剥离破坏准则,并建议考虑将滑移量最大值δu作为FRP-混凝土界面的剥离破坏准则。The intermediate FRP-concrete interfacial debonding failure may occur in midspan of strengthened reinforced concrete beams. Several calculating methods for predicting the interfacial shear stress were put forward by a number of researchers. However, existing methods for predicting the shear stresses led to quite different results. To gain a better understanding to the debonding failure, the intermediate shear stress was primarily evaluated by incorporating typical bond-slip (δ -τ ) constitutive models and the test results obtained by the authors and other researchers. Then a new simplified and reliable finite element method (FEM) model named 'beam segment' model is proposed and validated. Based on this model, the distributions of interfacial shear stress in FRP strengthened beams under the influence of various parameters are calculated and discussed. The experimental and calculated analyses indicate that the ultimate interface shear stress is not suitable for judging the debonding failures, and the maximal relative slip δ u between FRP and concrete is suggested as the debonding failure criterion.

关 键 词：纤维复合材料 加固混凝土梁 界面剪应力 粘结-滑移 界面剥离破坏 

分 类 号：TU375.1[建筑科学—结构工程]