We describe a nondestructive evaluation (NDE) method based on the propagation of highly nonlinear solitary waves (HNSWs) to determine the excess of water on the surface of existing concrete structures. HNSWs are induced in a one-dimensional granular chain placed in contact with the concrete to be tested. The chain is part of a built-in transducer designed and assembled to exploit the dynamic in...

Usually, materials are inspected by nondestructive methods to detect and evaluate defects that may cause failure under the designed operation conditions. However, the structure may also fail due to uncertainties of material properties like strength or hardness, and may also suffer from unexpected degradation during operation. A reliable NDE technique for detecting the inception of failure durin...

Examples of the need for nondestructive and remote sensing technologies for evaluating early stages of decay are presented. The need is critical to develop methods of analyzing internal decay, at the center of large wood members, and decay behind concealing coverings. Current technologies are reviewed and their inadequacies discussed. Acoustic emission and acousto­ ultrasonics appear to hold th...

During the last half century, the use of composite materials and structures has been increasing within many industries: aerospace, automotive, civil, marine, and railway engineering, wind power generation, and sporting goods, to name a few. There is, however, only a small open literature base concerning adhesively bonded composite repairs, primarily originating from within the aerospace industr...

Eddy current (EC) estimate of flaw size obtained from inservice inspection is often the primary means of assessing the structural integrity of steam generator tubes. Reliable prediction of failure pressure and leak rate in tubes with complex cracking requires more detailed information about the geometry and extent of degradation than is generally available from conventional bobbin coil examinat...

Eddy current models have matured to such a degree that it is now possible to simulate realistic nondestructive inspection (NDI) scenarios. Models have been used in the design and analysis of NDI systems and to a limited extent, model-based inverse methods for Nondestructive Evaluation (NDE). The science base is also being established to quantify the reliability of systems via ModelAssisted Prob...

Usually ultrasonic techniques tend to evaluate the closed cracks as smaller than the actual size. In this paper, we describe two strategic techniques for accurately evaluating the closed cracks by means of ultrasound. First, we show the advanced technique utilizing the thermal stress induced by cooling a cracked part. It is shown that a small amount of temperature decrease is effective to open ...

an important issue in power generation and petrochemical industries is the monitoring of pipe wall thickness and corrosion/erosion rate. the pipes are usually subject to erosive and/or corrosive environments and any failure could be catastrophic. while periodic manual ultrasonic thickness measurement is the common practice in many industries, in certain cases, where higher accuracies are requir...

Fatigue cracks are a major concern for aging metallic structures, as they can cause unexpected catastrophic failure. They often occur on hidden surfaces, e.g., under paint and rust or the interface between two structural layers, which makes visual detection difficult. Acoustic Emission (AE) is passive nondestructive evaluation (NDE) method that measures initiation progression of defects when st...

Additive manufacturing (AM) has the potential to revolutionize because it can fabricate complex geometries that are not possible with conventional processes. Qualification of AM parts remains challenging due solidification defects (e.g. porosity) and heterogeneous microstructure, both which strongly dependent on process parameters. Nondestructive evaluation (NDE) techniques desired provide time...