Romanowicz Paweł J, Szybiński Bogdan, Wygoda Mateusz
Department of Machine Design and Composite Structures, Faculty of Mechanical Engineering, Cracow University of Technology, ul. Warszawska 24, 31-155 Cracow, Poland.
Department of Product Technology and Ecology, College of Management and Quality Sciences, Cracow University of Economics, 31-510 Cracow, Poland.
Materials (Basel). 2024 Jul 18;17(14):3561. doi: 10.3390/ma17143561.
The application of the digital image correlation (DIC) contactless method has extended the possibilities of reliable assessment of structure strain fields and deformations throughout the last years. However, certain weak points in the analyses using the DIC method still exist. The fluctuations of the results caused by different factors as well as certain deficiencies in the evaluation of DIC accuracy in applications for hybrid steel/composite structures with adhesive joints are one of them. In the proposed paper, the assessment of DIC accuracy based on the range of strain fluctuation is proposed. This relies on the use of a polynomial approximation imposed on the results obtained from the DIC method. Such a proposal has been used for a certain correction of the DIC solution and has been verified by the introduction of different error measures. The evaluation of DIC possibilities and accuracy are presented on the examples of the static tensile tests of adhesively bonded steel/composite joints with three different adhesives applied. The obtained results clearly show that in a non-disturbed area, very good agreement between approximated DIC and FEM results is achieved. The relative average errors in an area, determined by comparison of DIC and FEM strains, are below 15%. It is also observed that the use of approximated strains by polynomial function leads to a more accurate solution with respect to FEM results. It is concluded that DIC can be successfully applied for the analyses of hybrid steel/adhesive/composite samples, such as determination of strain fields, non-contact visual detection of faults of manufacturing and their development and influence on the whole structure behavior during the strength tests, including the elastic response of materials.
在过去几年中，数字图像相关（DIC）非接触式方法的应用扩展了可靠评估结构应变场和变形的可能性。然而，使用DIC方法进行分析时仍存在某些弱点。不同因素导致的结果波动以及在钢/复合材料混合结构粘接接头应用中DIC精度评估的某些不足就是其中之一。在本文中，提出了基于应变波动范围的DIC精度评估方法。这依赖于对从DIC方法获得的结果施加多项式近似。这样的提议已用于对DIC解进行一定的修正，并通过引入不同的误差度量进行了验证。以使用三种不同粘合剂的粘接钢/复合材料接头的静态拉伸试验为例，介绍了DIC的可能性和精度评估。获得的结果清楚地表明，在无干扰区域，近似DIC结果与有限元法（FEM）结果之间取得了很好的一致性。通过比较DIC和FEM应变确定的区域内相对平均误差低于15%。还观察到，使用多项式函数的近似应变相对于FEM结果会得到更准确的解。得出的结论是，DIC可以成功应用于钢/粘合剂/复合材料混合样品的分析，例如应变场的确定、制造缺陷的非接触视觉检测及其发展以及强度试验期间对整个结构行为的影响，包括材料的弹性响应。
