變溫場中熱應(yīng)力測試技術(shù)研究

變溫場中非金屬材料因溫度變化所受到的拉壓應(yīng)力，可利用金屬絲的應(yīng)變－電阻效應(yīng)把構(gòu)件表面的應(yīng)變量直接變換為電阻相對變化量的原理，通過電阻應(yīng)變片進(jìn)行其應(yīng)變測量。已知主應(yīng)力方向的單向應(yīng)力狀態(tài)時，沿主應(yīng)力方向貼1 片應(yīng)變片可測得主應(yīng)變。已知主應(yīng)力方向的二向應(yīng)力狀態(tài)時，粘貼相互垂直的2 片應(yīng)變片可測得主應(yīng)變。未知主應(yīng)力方向時，應(yīng)粘貼相互成45°的3 個應(yīng)變片測其應(yīng)變分量并換算成主應(yīng)變。由銅－康銅T 型熱電偶測溫傳感器、BE120- 2BA 雙向應(yīng)變片測應(yīng)變傳感器、FLUKE 2285B 數(shù)據(jù)采集器、計(jì)算機(jī)及其應(yīng)用程序構(gòu)成的變溫場中熱應(yīng)力測量系統(tǒng)，實(shí)現(xiàn)了應(yīng)變和溫度的同時測量及其數(shù)據(jù)采集、處理、顯示等。
關(guān) 鍵 詞 ： 熱應(yīng)力； 溫度測量； 應(yīng)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