Study on the Influence of Rough Appearance of Concrete on DIC Measurement Error
蔡兴健①CAI Xing-jian；马丽莎②MA Li-sha；杨乙① YANG Yi；
李明辉① LI Ming-hui；周阳① ZHOU Yang
（①莱州汇金矿业投资有限公司，烟台 261400；②中国矿业大学（北京），北京 100083）
（①Laizhou Huijin Mining Investment Co.，Ltd.，Yantai 261400，China；
②China University of Mining and Technology（Beijing），Beijing 100083，China）
摘要：混凝土构件在长期服役过程中受到风浪、温度应力、腐蚀等外部环境侵蚀，导致混凝土表观粗糙不平。采用数字图像相关技术（DIC）计算力学响应下的混凝土表面应变场时，粗糙表观超过相机景深会引起离焦现象致使散斑退相关，使得 DIC 测量误差增大。针对此问题，基于 3D-DIC 系统计算物体表面三维形貌并以 Z 轴高度极差与平均灰度共同表征混凝土表面粗糙度，结合 DIC 成像规律与混凝土表面粗糙度的大小预留足够的景深并通过混凝土三点弯实验验证。结果表明：对于粗糙度 R（S 4.37mm，139）的混凝土，预留景深 0.81mm，DIC 数据平均偏差高达 42%；预留景深 4.48mm，DIC 数据平均偏差仅 12%。
Abstract: Concrete components are subjected to external environmental erosion such as wind, waves, temperature stress, and corrosion during long-term service, resulting in rough and uneven appearance of concrete. When using Digital Image Correlation (DIC) technology to calculate the surface strain field of concrete under mechanical response, roughness exceeding the camera depth of field can cause defocusing and speckle decorrelation, leading to an increase in DIC measurement error. To address this issue, a 3D-DIC system is used to calculate the three-dimensional morphology of the object surface and characterize the surface roughness of concrete using the Z-axis height range and average gray level. Combined with the DIC imaging law and the size of the concrete surface roughness, sufficient depth of field is reserved and verified through concrete three-point bending experiments. The results showed that for concrete with roughness RS (4.37 mm, 139), a reserved depth of field of 0.81 mm resulted in an average deviation of up to 42% in DIC data; and a reserved depth of field 4.48 mm, resulted in an average deviation ofonly 12% in DIC data.
关键词：数字图像相关技术；混凝土表面应变场；景深；散斑退相关；混凝土表面粗糙度
Key words: digital image related technology；surface strain field of concrete；depth of field；speckle regression correlation；surface
roughness of concrete
中图分类号：O348.1 文献标识码：A 文章编号：1006-4311（2024）26-100-03 doi:10.3969/j.issn.1006-4311.2024.26.029
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