In this paper, a standard test method of evaluating the measurement performance of distributed sensors such as Brillouin scattering based fiber optic sensors (FOSs) and other long gauge sensors for monitoring cracks is proposed. The performance evaluation of two types of Brillouin scattering based DFOSs named as BOTDR(Brillouin Optical Time Domain Reflectometry) and PPP-BOTDA (Pulse Pre-Pump Br...

The paper presents a new analytical model to study the evolution of radial cracking around a corroding steel reinforcement bar embedded in concrete. The concrete cover for the corroding rebar is modelled as a thick-walled cylinder subject to axisymmetrical displacement constraint at the internal boundary generated by expansive corrosion products. A bilinear softening curve reflecting realistic ...

Performance requirements of the patch repair material are strength, size stability, shieldability, durability, bond property with the substrate concrete, ductility and so forth. Various kinds of patch repair materials with short fibers have been developed and used. Engineered Cementitious Composites (ECC) which provides multiple cracking and strain hardening behavior is also one of the attracti...

Smart film crack monitoring method, which can be used for detecting initiation, length, width, shape, location, and propagation of cracks on real bridges, is proposed. Firstly, the fabrication of the smart film is developed. Then the feasibility of the method is analyzed and verified by the mechanical sensing character of the smart film under the two conditions of normal strain and crack initia...

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 ...

The optimal material processing in steel industry is difficult because of the multi-constituent and multiphase character of the commercial steels, variety of the possible processing paths, and plant specific equipment characteristics. This paper shows implementation of the genetic programming approach for crack presence modeling after rolling. The data (110 samples covering 7 different steel gr...

Concern over construction vibration-induced cracking has led to development of a new approach to vibration monitoring, an autonomous crack comparometer (ACC). This paper describes sensor performance and chronicles the first steps in the development of this concept, illustrated in Figure 1. A single sensor measures both weather-induced micrometer changes in crack width and those produced by habi...

The changes in elastic lattice-strain profiles and plastic zone around the fatigue crack in a compact-tension specimen were investigated during monotonic tensile loading and unloading cycles using neutron diffraction. Spatially-resolved strain measurements were performed on a 316 LN stainless steel to determine the in-plane (parallel to the loading direction) lattice-strain profiles ahead of th...