Application of digital speckle correlation method to disk surface thermal deformation measurement
-
摘要: 为了克服压力应变片测量热变形的不足,采用DSCM(数字散斑相关方法)对静止空心圆盘仅承受外缘热载荷时的表面热变形进行实时测量.实验系统中,采用电磁感应加热方式实现圆盘热边界条件的加载,并通过红外热像仪采集圆盘的实时温度分布数据.同时,为提高DSCM的测量精度,从CCD(charge coupled device)相机视场范围的选取、中焦距微距镜头的使用以及光源的布置等方面来降低离面位移和散斑质量等误差因素的影响.盘面热变形 位移的实验结果与理论结果的对比显示,两者符合较好,但仍存在一定偏差,最大绝对偏差为6μm,最大相对偏差为31%;盘外缘绝对偏差较大而相对偏差较小,盘内缘反之.对比结果验证了DSCM用于圆盘表面热变形测量的可行性,从而为涡轮盘盘面热变形研究提供了一种有效的实验工具.Abstract: To overcome the limitations of thermal deformation measurement conducted by strain gages, the DSCM (digital speckle correlation method) was used to determine the real-time surface thermal deformation of a static hollow disk subjected to thermal load on the outer rim. In the experiment system, electromagnetic induction heating method was applied to simulate the heat boundary of the disk and the real-time temperature distribution of the disk was obtained by infrared thermometer. Meanwhile, for the purpose of improving accuracy of DSCM, measures were taken by considering the range of field of CCD (change coupled device) camera view, the usage of medium focal length micro lens and the arrangement of illumination to lessen the effects of error factors like off-plane displacement and speckle image quality. The comparison between the experimental and theoretical results of thermal deformations shows that a good agreement is achieved, although some deviations still exist, and the maximum absolute deviations and relative deviations are 6μm and 31%, respectively; the absolute deviations of the outer rim are larger while the relative deviations are smaller,and this case is contrary to the inner rim. The results validate that the feasibility of DSCM for disk surface thermal deformation measurement, thus providing an effective experimental tool on turbine thermal deformation investigations.
-
[1] YapIcI H,Bastürk G.Numerical solutions of transient conjugate heat transfer and thermally induced stress distribution in a heated and rotating hollow disk[J].Energy Conversion and Management,2005,46(1):61-84. [2] Hosseini K S A,Naghdabadi R.Thermoelastic analysis of a functionally graded rotating disk[J].Composite Structures,2007,79(4):508-516. [3] Vullo V,Vivio F.Elastic stress analysis of non-linear variable thickness rotating disks subjected to thermal load and having variable density along the radius[J].International Journal of Solids and Structures,2008,45(20):5337-5355. [4] PENG Xulong,LI Xianfang.Thermal stress in rotating functionally graded hollow circular disks[J].Composite Structures,2010,92(8):1896-1904. [5] Hassani A,Hojjati M H,Mahdavi E,et al.Thermo-mechanical analysis of rotating disks with non-uniform thickness and material properties[J].International Journal of Pressure Vessels and Piping,2012,98:95-101. [6] 张如一,沈观林,李朝弟.应变电测与传感[M].北京:清华大学出版社,1998. [7] 李巧真,李刚,韩钦泽.电阻应变片的实验与应用[J].实验室研究与探索,2011,30(4):134-137. LI Qiaozhen,LI Gang,HAN Qinze.Experiment and application of resistance strain gauge[J].Research and Exploration in Laboratory,2011,30(4):134-137.(in Chinese) [8] Peters W H,Ranson W F.Digital imaging techniques in experimental mechanics[J].Optical Engineering,1982,21(3):427-431. [9] Yamaguchi I.Speckle displacement and decorrelation in the diffraction and image fields for small object deformation[J].Optica Acta,1981,28(10):1359-1376. [10] 王怀文,亢一澜,谢和平.数字散斑相关方法与应用研究进展[J].力学进展,2005,35(2):195-203. WANG Huaiwen,KANG Yilan,XIE Heping.Advance in digital speckle correlation method and its applications[J].Advances in Machanics,2005,35(2):195-203.(in Chinese) [11] Lyons J S,Liu J,Sutton M A.High-temperature deformation measurements using digital-image correlation[J].Experimental Mechanics,1996,36(1):64-70. [12] 李鸿琦,邢冬梅,马世虎,等.梯度功能材料热弹性应变场分析[J].实验力学,2002,17(3):274-278. LI Hongqi,XING Dongmei,MA Shihu,et al.Experiment study of thermal strain field of functionally gradient material[J].Journal of Experimental Mechanics,2002,17(3):274-278.(in Chinese) [13] 潘兵,吴大方,高镇同.基于数字图像相关方法的非接触高温热变形测量系统[J].航空学报,2010,31(10):1960-1967. PAN Bing,WU Dafang,GAO Zhentong.A non-contact high-temperature deformation measuring system based on digital image correlation technique[J].Acta Aeronautica et Astronautica Sinica,2010,31(10):1960-1967.(in Chinese) [14] 戴福隆,沈观林,谢惠民.实验力学[M].北京:清华大学出版社,2010. [15] 王冬梅,方如华,秦玉文.数字图像相关测量的误差分析及其改进措施析[J].实验力学,1998,13(3):416-422. WANG Dongmei,FANG Ruhua,QIN Yuwen.Measuring errors analysis and improvement of digital image correlation method measurement system[J].Journal of Experimental Mechanics,1998,13(3):416-422.(in Chinese) [16] Sutton M,McNeill S,Helm J,et al.Advances in two-dimensional and three-dimensional computer vision[J].Photomechanics,2000,77:323-372. [17] 孟利波,金观昌,姚学锋.DSCM 中摄像机光轴与物面不垂直引起的误差分析[J].清华大学学报:自然科学版,2006,46(11):1930-1932. MENG Libo,JIN Guanchang,YAO Xuefeng.Errors caused by misalignment of the optical camera axis and the object surface in the DSCM[J].Journal of Tsinghua University:Science and Technology,2006,46(11):1930-1932.(in Chinese) [18] 吕文林.航空发动机强度计算[M].北京:国防工业出版社,1998.
点击查看大图
计量
- 文章访问数: 1188
- HTML浏览量: 2
- PDF量: 829
- 被引次数: 0