含界面裂纹的GFRP沥青混合料巴西盘断裂力学分析

摘要

The mechanics property near interface crack tip is studied in order to strength analysis, which interface is between GFRP and asphalt mixtures. Bimaterial Brazilian Disk specimens with prefabricated interface crack are designed. 27 Brazilian Disk specimens are tested by loading angle in the range of 25 degree to 90 degree, and experimental data are recorded, such as ultimate load, crack propagation path, fracture form, etc. Finite element model of GFRP asphalt mixtures Brazilian Disk is built, considering the GFRP orthotropic property. Interface stress intensity factors ( SIF) are calculated applying numerical extrapolation method, and fracture mechanics performance of GFRP asphalt mixtures Brazilian Disk is studied by theoretical analysis and experimental research. The results show that the bimaterial Brazilian Disk specimens with prefabricated interface crack can fully reflect fracture types of GFRP and asphalt mixtures, which is an efficient experiment method, that interface SIF acting as mechanics evaluation parameter, can well explain experiment phenomena, and that GFRP and asphalt mixtures Brazilian Disk specimens with prefabricated interface crack are in accordance with elliptic strength criterion.%为研究GFRP沥青混合料界面裂尖力学特性,对混合料进行强度分析,设计了含预制界面裂纹的双材料巴西盘试件,实测了加载角度在25°~90°之间27个巴西盘试件断裂荷载、裂纹扩展路径和断口形式等试验数据,结合试验数据建立了考虑GFRP正交异性双材料巴西盘有限元模型,采用数值外插法反算了界面应力强度因子,进行了GFRP沥青混合料巴西盘断裂力学性能的理论分析和试验研究.结果表明,含预制界面裂纹的双材料巴西盘试件能全面地反映GFRP沥青混合料的断裂形态,是一种有效的试验方法;以界面应力强度因子作为力学评价指标,能够很好地解释试验现象;含预制界面裂纹的GFRP沥青混合料巴西盘符合椭圆强度准则.