GFRP工字梁腹板剪应力分布规律研究

Study on the distribution of shear stress in the web of GFRP I-girder

目前,玻璃纤维增强塑料(glass fiber reinforced plastic,GFRP)与混凝土组合梁的抗剪切性能研究中,常直接把GFRP型材当成各向同性材料来计算,来达到简化计算的目的。然而,GFRP是各向异性材料,计算时直接采用由各向同性材料推导出的公式是偏于不合理的。为此,利用有限元软件ABAQUS,对不同铺设方式的GFRP工字梁进行了数值仿真,输出了腹板中各层层合板的剪应力分布云图,并精确绘制了相应的沿腹板高度的剪应力分布图。研究发现,0°和90°铺层的剪应力分布大致为抛物线,表现出与各向同性材料的相似性,而其他角度的铺层中,剪应力的分布离散性较大。所有的铺设情况中,腹板中的最大剪应力为平均剪应力的1.06倍。

At present,for the purpose of simplifying calculation,glass fiber reinforced plastic（ GFRP） protruded profiles are usually considered as isotropic materials in the studies on the shear performance of GFRP and concrete composite beams. However,it is unreasonable to use the theoretical formula derived from the isotropic materials directly,due to the anisotropy of GFRP. To this end,finite element simulation software ABAQUS was used to analyze the GFRP I-girders composed of different laying modes,and the distribution nephograms of shear stress and the distribution regularity along the web of different layers were obtained. The results show that the shear stress distributions of ply angle 0°and 90° were parabolic,which are similar to those of isotropic materials,and layers with other ply angles were quite different. Among those analysis results,the maximum shear stress in the web is 1. 06 times of the average value.