GFRP型材-混凝土组合梁受弯性能分析

Flexural performance analysis of GFRP profile-concrete composite beams

为了研究玻璃钢纤维(GFRP)型材-混凝土组合梁的受弯性能,采用有限元分析软件ABAQUS建立其数值模型并进行模拟分析。对混凝土采用塑性损伤模型,并考虑了GFRP型材的各向异性的特征,连接界面采用牵引-分离模型来模拟GFRP型材与混凝土的粘结-滑移行为。试验结果验证了模拟分析的正确性。此外,进行了参数扩展分析,研究了混凝土板截面尺寸、GFRP型材截面尺寸(腹板高度和腹板、翼缘板厚度)对GFRP型材-混凝土组合梁受弯性能的影响。结果表明:剪力键间距为100mm的组合梁的极限承载力比间距为150、200mm的试件分别高21.4%和30.7%。FRP剪力键可有效提高抗剪性能,改善界面粘结性能。混凝土截面高宽比超过1.2时,组合梁破坏模式从受弯破坏向剥离破坏转变。合理设计组合梁截面尺寸可以有效地提高组合梁的极限抗弯承载力、最大挠度和拟延性特征,在力学性能和工程造价之间取得良好的平衡。

In order to study to flexural performance of glass fiber reinforced polymer(GFRP)profiled-concrete composite beams,the finite element(FE)analysis software ABAQUS was used to establish numerical model for simulation analysis.The concrete damage plastic(CDP)model was adopted for concrete,and the anisotropy of GFRP profile was taken into consideration.The traction-separation model was used to investigate simulate the bond-slip behavior between GFRP profile and concrete.The simulation analysis was verified by the corresponding experimental results.In addition,the parametric expansion analysis was conducted to investigate the effects of the cross-sectional dimension of concrete and GFRP profile(the height of web,the thickness of web and flange)on the flexural performance of GFRP profiled-concrete composite beams.The results show that the deflection-limit load of composite beam with shear connectors spacing of 100mm is 21.4%and 30.7%,respectively,higher than that of specimens with spacing of 150,200mm.FSK can effectively enhance the shear performance and bonding behavior of the interface.The failure mode of composite beam changes from bending failure to debonding failure when the ratio of concrete height to width exceeds 1.2.Reasonable design of the sectional size of composite beams can efficiently improve the ultimate flexural capacity,maximum deflection and quasi-ductility characteristics of composite beams,and achieve a good balance between mechanical properties and engineering cost.