复合材料垂尾受热应变激增问题分析

ANALYSIS OF STRAIN SURGE CAUSED BY HEATING IN COMPOSITE VERTICAL TAIL

为了解决复合材料垂尾在无机动时应变电桥出现应变激增的问题,本文建立了一种采用应变法测量复合材料翼面结构飞行载荷的物理模型,并进行定性验证试验。理论分析和试验结果表明,垂尾单侧翼面受热时,2个弯矩电桥应变急剧变大(应变值分别为175.24和254.15),而2个剪力电桥的变化很小(应变值分别为13.52和3.83),其根本原因是由于复合材料的各向异性,而热导率和组成电桥的两个应变片之间的距离放大了这种热应变。这为后续采用应变法测量热环境下飞机复合材料的载荷提供了一定的理论依据。

In order to solve the problem of the strain surge in the composite material vertical-tail strain bridge,a physical model for measuring the flight load of the composite material wing structure by the strain method is established,and the qualitative verification test is carried out.The theoretical analysis and the experimental results show that the strain of the two bending moment bridges increases sharply(the strain values are 175.24 and 254.15,respectively)while the strain values of the two shear bridges change but little(the strain values are 13.52 and 3.83,respectively),because of the heterogeneity of the composite,and the fact that the thermal strain is amplified by the thermal conductivity and the distance between the two strain gauges to make up the bridge.This result provides a theoretical basis for the measurement of the composite load in the thermal environment by the strain method.