温度-荷载作用下玻璃纤维增强塑料-泡沫夹层结构Ⅰ型断裂韧性分析

Analysis of Ⅰ-type fracture toughness of sandwich structure with GFRP skins and a foam core under coupling effects of temperature and loading

以玻璃纤维增加塑料(GFRP)-泡沫夹层结构为研究对象,在不同温度条件下,采用拉伸试验确定聚氨酯泡沫芯材料的拉伸性能;经差示扫描量热分析法(DSC)测试GFRP树脂的玻璃化转变温度;通过双悬臂梁(DCB)试验研究,测试不同温度(30、50、70和90℃)条件下,夹层结构的I型裂纹扩展形态和界面应变能释放率,分析温度对GFRP-泡沫夹层结构界面数性能的影响。结果发现:GFRP树脂的玻璃化温度为90℃;温度对聚氨酯泡沫的拉伸强度和拉伸模量影响较小;随着温度的升高,GFRP-泡沫夹层结构的荷载呈下降趋势,界面应变能释放率的峰值越来越大。运用能量释放率断裂准则判别裂纹扩展符合理论要求。

With glass fiber reinforced plastic （ GFRP ） -loam sandwich structure as the research object,the tensile property of polyurethane foam core material was studied by intension test under different temperature, and the glass transition temperature of GFRP resin was tested by differential scanning calorimetry,and with double cantilever beam （DCB ） experiment,the crack growth morphology and peak interfacial strain energy release rate of sandwich structures I-type were investigated under different temperature（30,50,70,and 90℃）.Results showed that the glass transition temperature of GFRP resin was 90℃,the effect of temperature on tensile strength and tensile modulus of polyurethane foam material was much less.The load of GFRP - foam sandwich structure decrease with the increase of the temperature, but the peak interfacial strain energy release rate was increased synchronously. Thu s,the energy release rate of the fracture riterion for the crack propagation is consistent with theoretical requirements.