PSI - Issue 66

Ram Lal Riyar et al. / Procedia Structural Integrity 66 (2024) 181–194 Ram Lal Riyar et. al./ Structural Integrity Procedia 00 (2025) 000–000

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reaching the maximum load due to inability to resist material against applied load. Crack resistance decreases as corrosion intensity rises. The graph demonstrates the significant decline in fracture toughness as corrosion intensifies. K IC = ௉௠௔௫ ௕௛ ௌ య మ f ( ௔ ௛ ) (2) Where f( ௔ ௛ ) = 2.9( ௔ ௛ ) 1/2 -4.6( ௔ ௛ ሻ 3/2 +21.8( ௔ ௛ ) 5/2 -37.6( ௔ ௛ ሻ 7/2 + 38.7( ௔ ௛ ሻ 9/ 2 Here, the beam span is denoted as S, the breadth of the beam is represented by b, the depth of the beam is indicated as h, and the crack length of the specimen is denoted as ‘a’. It was noticed that as the crack length grows, the fracture energy tends to rise as well. Larger fractures take more energy to break the atomic bonds at the crack front and produce new surfaces since higher fissures have a bigger surface area. The energy needed to expand the crack further rises as the crack widens due to increasing stress concentrations near the crack tip. After the peak load, fracture energy reduces and as the corrosion increases, fracture energy reduces sharply. The structural integrity and functionality of materials and constructions are significantly impacted by the increase in equivalent fracture length brought on by corrosion. The ability of components to bear loads may be reduced by the growth of cracks, which can also affect their stiffness and strength and make them more susceptible to catastrophic collapse. The material becomes increasingly vulnerable to localized corrosion phenomena, including pitting or crevice corrosion, as the corrosion process advances. These microscopic cracks or voids, which function as stress raisers and encourage crack initiation while lowering the material's effective fracture energy, may be produced by these localized corrosion characteristics. Furthermore, corrosion may result in material mass loss, which reduces the cross-sectional area and weakens the structure. This material loss may lower the material's overall ability to absorb energy, which may lessen the fracture energy. The structural integrity and dependability of materials and components are significantly impacted by the reduction in fracture energy brought on by corrosion. It lowers the material's capacity to withstand crack growth and absorb energy. 3.5. DIC analysis of reinforced beam The FPZ has a significant impact on the fracture behaviour of concrete, leading to damage that causes a softening of the material. It is possible to determine the size of FPZ by analysing the displacement fields using digital image correlation. Since it explains fracture behaviour, characterizing the fracture process zone has grabbed research attention. FPZ regulates the fracture behavior in concrete. Therefore, its precise experimental and theoretical assessment has remained crucial. The zone formed around the crack tip moves with a progressing crack and is observed as a material property. The U-displacement indicates that the material is moving to the right (positive displacement) and left (negative displacement) on either side of the notch. It is useful to look at the displacements along a horizontal cross-section to better comprehend the behaviour towards the tip.

Figure 12: (a) U-displacement (b) Displacement Distribution along depth (c) Strain of reinforced concrete beam.