Nondestructive Evaluation Of Cracks Research Articles

Integration of digital shearography and FEM for non-destructive evaluation of internal cracks in GRE pipes

Pipes made of glass fiber-reinforced epoxy (GRE) are often exposed to complex environmental conditions, which can make them prone to internal cracking. Quantitative, non-destructive evaluation of cracks can reduce unintended failures and improve system reliability. The use of digital shearography, a modern non-destructive method based on laser interferometry, in the diagnosis of composite materials has drawn attention in recent years. In this paper, a model for the quantitative evaluation of subsurface cracks in various locations on GRE pipes was developed by integrating the finite element method and shearography with thermal stimulation. The response surface method was used to design the simulations, and the effect of crack dimensions and location on the phase map and out-of-plane surface strain component was investigated. The results demonstrated that the crack placement angle relative to the shearography device is effective on crack detectability due to the change in the actual shearing size. A model was then presented to estimate the length and depth of the crack based on the displacement derivative graph by using analysis of variance and regression techniques. By determining the out-of-plane displacement derivative, the proposed model enables precise estimation of the dimensions and location of subsurface cracks.

Nondestructive Evaluation of Cracks and Plastic Deformation in an Austenitic Stainless Steel by Using Martensitic Transformation

Nondestructive Evaluation of Cracks and Plastic Deformation in an Austenitic Stainless Steel by Using Martensitic Transformation

Nondestructive Evaluation of Cracks and Plastic Deformation in an Austenitic Stainless Steel by Using Martensitic Transformation

Nondestructive Evaluation of Cracks and Plastic Deformation in an Austenitic Stainless Steel by Using Martensitic Transformation

Nondestructive Evaluation of Cracks and Plastic Deformation in an Austenitic Stainless Steel by Using Martensitic Transformation

Nondestructive Evaluation of Cracks and Plastic Deformation in an Austenitic Stainless Steel by Using Martensitic Transformation

Non-destructive evaluation of cracks in massive concrete using normal dc resistivity logging

Discontinuities are one of the most harmful damage to the durability of concrete structures. Currents approaches are limited to assessments of surface damages, even if non-destructive methods appear to be effective for the detection and the location of cracks. That is why, these methods might be unsuitable for investigation of massive concrete body as dams and locks. Present works aim at the presentation of new results with electrical resistivity to study damages within concrete structures. In this article, the electrical resistivity focused on the study of cracks and discontinuities (concrete joints, interfaces…) in massive concrete structures by measurements done in preexisting boreholes. The used array is the normal dc resistivity logging. The study presents numerical and experimental results. First, modeling allows correcting experimental data. Then, development shows the sensitivity relatively to the discontinuity characteristics (aperture and the resistivity contrast between the discontinuity and the concrete). The tests on a real structure are carried out to define the methodology for on-site measurement. Results support the modeling.

Nondestructive evaluation of cracks in a paramagnetic specimen with low conductivity by penetration of magnetic fluid

This paper proposes a nondestructive testing method for detecting a crack in an Inconel ® specimen. Because of the low conductivity and permeability of Inconel, cracks are difficult to detect using the electromagnetic method, until now. In our method, magnetic fluid penetrates a surface crack in the Inconel specimen, and the distribution of the magnetic field is measured using a scan-type magnetic camera. The magnetic field leakage and induced current methods were examined. With our method, cracks can be evaluated. This research can be used to detect and evaluate cracks on non-ferrous and non-metallic materials such as ceramic, composite, and synthetic resins.

き裂の高感度非破壊評価

き裂の高感度非破壊評価

Nondestructive Evaluation of Cracks and Elastic Constants of Concrete Using Transient Elastic Waves

Nondestructive Evaluation of Cracks and Elastic Constants of Concrete Using Transient Elastic Waves