光纤传感器对合金结构瞬态高温应变测量的适用性研究

高温下结构应变测量数据的重复性是判断测量结果有效性的前提和基础。文章采用石英灯辐射加热技术构建瞬态辐射加热环境，以薄壁平板型合金材料结构为测量对象，对光纤应变传感器在瞬态加热环境下应变测量数据的重复性进行实验研究，以确定其对合金材料瞬态高温下应变测量的适用性。结果表明：光纤传感器与K型热电偶的测温偏离量小于1.76%；在安装面加热状态，瞬态加热温升速率最高达到18 ℃/s，结构最高温度达到850 ℃，此温度下测得的结构件最大应变为9 848.2 με，3次实验测量数据的重复性优于1.42%；非安装面加热状态、结构温度650 ℃下的3次测量数据重复性为0.95%，且与安装面加热状态、相同温度下的测量数据平均值的相对差异仅为0.67%。综上说明，所采用的光纤应变传感器适用于石英灯瞬态辐射加热环境下合金结构件的应变测量。

Applicability study on optical fiber sensor for transient HT strain measurement of alloy structures

The repeatability of structural strain measurement data at high temperature (HT) is the premise and basis for judging the validity of measurement results. In this paper, the quartz lamp radiation heating technology was used to construct the transient radiation heating environment and the thin-walled flat alloy material structure was taken as the measurement object. The repeatability of strain measurement data obtained by optical fiber strain sensor in the transient heating environment was experimentally studied, so as to verify its applicability to the transient HT strain measurement of alloy materials. The test results show that the deviation between the optical fiber sensor and the K-type thermocouple is less than 1.76%. When mounting surface heated, the maximum transient temperature rising rate reaches 18 ℃/s, the maximum structural temperature reaches 850 ℃, and the maximum strain of the structural part is 9 848.2 με under this temperature. The repeatability of the three experimental measurements is better than 1.42%. When non-mounting surface heated, the difference in the mean of the measured data under the same temperature is only 0.67%. In conclusion, the optical fiber strain sensor is suitable for the strain measurement of alloy structure in the transient radiation heating environment by quartz lamp.