Crack detection is one of the important tasks for industrial materials and products from the standpoint of safety. The assessment of the crack geometry would be a crucial parameter for quality control of products. The crack width and length could be rather easily identified by inspecting the actual surface picture. However, the depth of small crack would be difficult to estimate non-destructive...

An experimental investigation dealing with failure characterization of 63/37 soldercopper interfaces is presented. The method of moird interferometry is used for mapping elasto-plastic deformations in bimaterials subjected to predominantly tensile loading. A method for quantifying the fracture parameter--the J-integral--using full-field measurement of crack opening displacements has been develo...

Ultrasonic is one of the most common uses of a non-destructive evaluation method for crack detection and characterization. The effectiveness of the acoustic-ultrasound Structural Health Monitoring (SHM) technique for the determination of the depth of the surface crack was presented. A method for ultrasonic sizing of surface cracks combined with the time domain and frequency spectrum was adopted...

Cracks, the important factor of structure failure, reflect structural damage directly. Thus, it is significant to realize distributed, real-time crack monitoring. To overcome the shortages of traditional crack detectors, such as the inconvenience of installation, vulnerability, and low measurement range, etc., an improved topology-based cable sensor with a shallow helical groove on the outside ...

Vibrothermography is a technique for finding cracks and delaminations through infrared imaging of vibration-induced heating. While vibrothermography has shown remarkable promise, it has been plagued by persistent questions about its reproducibility and reliability. Fundamentally, the crack heating is caused by the vibration, and therefore to understand the heating process we must first understa...

Prediction of crack growth and fatigue life estimation of metals using linear/nonlinear acousto-ultrasound methods is an ongoing issue. It is known that by measuring nonlinear parameters, the relative accumulated fatigue damage can be evaluated. However, there is still a need to measure two crack propagation states to assess the absolute residual fatigue life. A procedure based on the measureme...

In 2004, a team comprised of researchers and service providers launched the Safer Crack Use, Outreach, Research and Education (SCORE) project in the Downtown Eastside of Vancouver, British Columbia, Canada. The project was aimed at developing a better understanding of the harms associated with crack cocaine smoking and determining the feasibility of introducing specific harm reduction strategie...

The assumption of ellipsoidal flaw geometry has been widely used in calculations of the probability of structural failure conditioned on nondestructive (ND) measurements. Clearly, in most cases the flaw geometry is not ellipsoidal and in the particular case of cracks the actual geometry may deviate significantly from a degenerate ellipsoid (i.e., a planar crack with an elliptical plan-view shap...

This research studies the performance of a battery-free wireless antenna sensor for measuring crack propagation. In our previous work, a battery-free folded patch antenna was designed for wireless strain and crack sensing. When experiencing deformation, the antenna shape changes, causing shift in electromagnetic resonance frequency of the antenna. The wireless interrogation system utilizes the ...