不同温度环境下复合材料/金属混合壁板结构热应力试验研究

EXPERIMENTAL STUDY ON THERMAL STRESS OF FASTENED HYBRID COMPOSITE/METALLIC STRUCTURES UNDER DIFFERENT TEMPERATURES

极端气候条件,如高温、低温和湿热环境,均会影响飞机上复合材料/金属混合结构的承载能力和工作寿命,进而影响飞机的飞行性能和安全。由于复合材料和金属材料之间的热膨胀系数差异较大,实际飞行中遇到的温度变化会导致复合材料元件和金属元件内部产生较高的热应力。这种附加热应力会改变复合材料/金属混合连接结构内部的载荷传递和内应力分布情况。对大规模、多钉连接的复合材料/金属混合结构壁板在不同温度环境中的热力学行为进行了试验研究,并研究了不同温度条件下受到单向拉伸载荷时的热力响应。通过试验过程中的应变变化,对不同环境和载荷条件下复合材料/金属混合结构内不同组件的应力分布和钉载情况进行了分析。

Extreme climatic conditions,such as hot,cold and hot-humid environment,affect the bearing performance and the life expectancy of composite and metal hybrid structural components in aircraft,which have a great impact on the flight performance and safety of the aircraft.Due to the large coefficient of thermal expansion mismatch between the composite and metallic structures,the temperature change in the actual flight condition induces high thermal stresses in both composite component and metallic component.This additional stress would alter load transfer and internal stress distribution in fastened hybrids of composite and metallic structure.Thermal/mechanical behavior of the large-scale,multi-joint hybrid composite/metal structure was investigated experimentally in different temperature conditions,as well as bearing axial load under different temperatures.The internal stress distribution of different components and fasteners in hybrid composite/metal structure under different temperature and load conditions was obtained by the strain gage method.