Uniaxial Static Stress Estimation for Concrete Structures Using Digital Image Correlation

This paper proposes a static stress estimation method for concrete structures, using the stress relaxationmethod (SRM) in conjunction with digital image correlation(DIC). The proposed method initially requires a small hole to be drilled in the concrete surface to induce stress relaxationaround the hole and, consequently, a displacement field. DIC measures this displacement fieldby comparing digital imagestaken before and after the hole-drilling. The stress level in the concrete structure is then determined by solving an optimization problem, designed to minimize the difference between the displacement fieldsfrom DIC and the one from a numerical model. Compared to the pointwisemeasurements by strain gauges, the full-field displacement obtained by DIC provides a larger amount of data, leading to a more accurate estimation. Our theoretical results were experimentally validated using concrete specimens, demonstrating the efficacy of the proposed method.