基于数字图像相关的机翼有限元模型试验验证

针对无人机机翼承载变形,传统测试系统只能提供离散、有限个数据点用于有限元模型验证的局限性,采用数字图像相关(digital image correlation,DIC)方法,测量某无人机机翼在压缩载荷作用下蒙皮表面的挠度场和应变场。基于MATLAB最近点迭代算法,实现数值模拟与180 000个DIC数据点的线性回归分析。结果表明:三组试验测得翼尖最大位移分别为92.8 mm、89.5 mm和87.5 mm,模拟结果为86.2 mm,相对误差均在10%以内;两段分析区域的展向正应变场,平均试验结果与模拟的相关系数分别为0.88和0.87,两者吻合度良好,所建立的有限元模型合理。

Experimental Validation of a Finite Element Model of Wing Using Digital Image Correlation

Regrading the limitation of traditional measurement systems which only provide a limited number of data points at discrete positions to validate finite element (FE) models, digital image correlation (DIC) method was applied to investigate deflection field and strain field of skin surface of an unmanned-aerial-vehicle wing under compressive load. Based on MATLAB Iterative Closest Point algorithm, linear regression analysis was carried out between numerical simulations and experimental measurements with around 240,000 data points. Results show that maximum displacements of wing tip are equal to 92.8 mm, 89.5 mm and 87.5 mm, while 86.2 mm is predicted by the simulation, thus relative errors are less than 10%. The good agreement involving normal strain field in the direction of wing span is also achieved, with correlation coefficients from 0.93 to 0.94, the established FE model is rational.