复合材料垂尾表面应变计粘贴技术

Strain Gauge Pasting Technology on Surface of Composite Vertical Tail

应变电测法是飞机飞行载荷测试最常用的方法之一。研究了纤维增强层合复合材料垂尾的飞行载荷应变电测方法。首先建立复合材料垂尾有限元模型,计算了在均布载荷下垂尾表面应变分布。然后根据有限元仿真应变分布结果,避开应力集中部位选取应变片粘贴位置,设计载荷测试电桥,利用载荷标定试验可测得垂尾的飞行载荷。最后对相同层数不同铺层顺序的垂尾模型进行计算,对应变片粘贴位置的表面应变进行细观分析和比较,分析了铺层顺序对表面应变的影响。计算结果表明,表层铺层角度对应变测试结果有较大影响,复合材料结构应变测试时应考虑结构的铺层顺序;而在载荷测试时,选取线性应变区则可不考虑该影响。

Strain electrical measuring method is one of the most commonly used methods in aircraft flight load test.The method of fiber reinforced laminated composite vertical tail load test was studied.Firstly,finite element model of composite vertical tail was established,and the surface strain distribution of vertical tail under uniform load was calculated.Secondly,according to the strain distribution of finite element simulation,strain gauges were placed and load test bridge were designed,which should avoid stress concentration area,calibration experiment should be carried out to measure the flight load of vertical tail.Finally,models of same ply number with different stacking sequence were stimulated,micromechanical study and comparison of the strain at the position of strain gauges was conducted to analysis the influence of stacking sequence on surface strain of composite structure.The results showed that the ply angle of surface composite layer had a great influence on strain test results.The stacking sequence of composite should be taken into account when testing the strain of composite structures,however,the influence could leave out of account during load testing experiment.