變溫場中熱應力測試技術研究

變溫場中非金屬材料因溫度變化所受到的拉壓應力，可利用金屬絲的應變－電阻效應把構件表面的應變量直接變換為電阻相對變化量的原理，通過電阻應變片進行其應變測量。已知主應力方向的單向應力狀態時，沿主應力方向貼1 片應變片可測得主應變。已知主應力方向的二向應力狀態時，粘貼相互垂直的2 片應變片可測得主應變。未知主應力方向時，應粘貼相互成45°的3 個應變片測其應變分量并換算成主應變。由銅－康銅T 型熱電偶測溫傳感器、BE120- 2BA 雙向應變片測應變傳感器、FLUKE 2285B 數據采集器、計算機及其應用程序構成的變溫場中熱應力測量系統，實現了應變和溫度的同時測量及其數據采集、處理、顯示等。
關 鍵 詞 ： 熱應力； 溫度測量； 應變測量； 變溫場
Abstract: The expanding and contracting strain of nonmetal material in change temperature field varies with temperature. Using strain resistance effect of metal wire, the strain variable of surface of component is changed into relative variable of resistance, the strain variable is measured with resistance strain chip. When the state of single -way stress to main stress direction was known, a strain chip is attached along main stress direction, the strain variable can be measured. When the state of double-way stress to main stress direction was known, two strain chips each other are attached perpendicularly, the strain variable can be measured. When the main stress direction was not known, three strain chips each other are attached in 45°angle , the local strain variable can be measured and is converted into the main strain variable. The test system for the heat strain in change temperature field is composed of copper T thermocouple temperature sensor, sensor with BE120-2BA double-way strain chip, FLUKE 2285B data acquisition device, computer and application program. The strain and the temperature measured at one time, and the stress test, data acquisition, data processing and displaying are realized.
Key Word: Heat strain; Temperature measure; Strain measure; Change temperature field