Application of Digital Image Correlation for Strain Mapping of Structural Elements and Materials

Area of Science:

• Materials Science
• Mechanical Engineering
• Structural Analysis

Background:

• Strain measurement is critical for understanding material and structural behavior.
• Traditional strain gauges have limitations in capturing full-field, 3D deformation.
• Digital Image Correlation (DIC) offers an advanced optical alternative for comprehensive strain analysis.

Purpose of the Study:

• To compare the accuracy and applicability of the strain gauge method and the DIC method for measuring strain in large-scale structural elements.
• To investigate the benefits and challenges of using DIC for full-scale construction testing.
• To develop and present a methodology for strain and displacement measurement in complex structural components.

Main Methods:

• Quasi-static strength tests and advanced structural research were conducted.
• Full-scale construction testing of highly stressed components, including new wagon designs, was performed.
• A comparative analysis using a standard shear-by-tensile test of CFRP composite was employed, with strain gauge measurements used for DIC validation.

Main Results:

• The DIC method provides valuable visualization of deformation patterns in large-scale elements.
• A good match between DIC and strain gauge measurements was achieved for strain values of 0.3% and above.
• Accuracy decreased for strain values below 0.3%, indicating a limitation for very low strain measurements.

Conclusions:

• The DIC method is a versatile technology for detailed component behavior analysis in complex structures.
• The developed methodology is suitable for measuring strain and displacement in heavily loaded transportation components, such as railway elements.
• DIC offers significant advantages for assessing 3D strain fields across entire areas of interest in structural testing.