Nondestructive Testing (NDT)

The aim of this book is to collect the newest contributions by eminent authors in the field of NDT-SHM, both at the material and structure scale. It therefore provides novel insight at experimental and numerical levels on the application of NDT to a wide variety of materials (concrete, steel, masonry, composites, etc.) in the field of Civil Engineering and Architecture

Nondestructive testing using ultrasonic sensor

Nondestructive testing (NDT) is the process of inspection or evaluating materials or component without destroying the functionality, serviceability and the structure of the testing product. Therefore, after the inspection is done the testing product can still be used as usual compared to the destructive testing that can cause the damage to the testing product. In the other word destructive testing has limitation because of the technique need a sampling product rather than on the materials is already put into the service. NDT are often used to determine the properties of the materials such as strengthen ductility, porosity and toughness. Todays, NDT are widely used in industries, manufacturing, and fabrication and in service inspection to ensure the quality of the product. Besides that, NDT also can reduce production cost by minimize the damage onto the product and also can reduce the production time by without damaging the testing product. Also in construction field, there are many benefits from NDT process toward this area such as to evaluate the strength of concrete. There are many method of NDT today such as Magnetic Particle Testing, Ultrasonic Testing, and Vibration Analysis. For testing of the building basically people are used the Ultrasonic Pulse Velocity (UPV) and Rebound Hammer. This paper is specifically discussed about the Nondestructive Testing (NDT) by using Ultrasonic

Electrical impedance spectroscopy-based nondestructive testing for imaging defects in concrete structures

An electrical impedance spectroscopy-based nondestructive testing (NDT) method is proposed to image both cracks and reinforcing bars in concrete structures. The method utilizes the frequency-dependent behavior of thin insulating cracks: low-frequency electrical currents are blocked by insulating cracks, whereas high-frequency currents can pass through the conducting bars without being blocked by thin cracks. Rigorous mathematical analysis relates the geometric structures of the cracks and bars to the frequency-dependent Neumann-to-Dirichlet data. Various numerical simulations support the feasibility of the proposed method

Feasibility of Nodestructively Evaluating the M140 Recoil Piston Head Weld

The application of nondestructive testing (NDT) to a weld cracking problem on the M140 Recoil Piston is discussed. Addressed in the presentation is the technique used for screening recoil pistons for crack sensitive weld filler metal and the inspection of piston welds for flaw discontinuities

The detection of tightly closed flaws by nondestructive testing (NDT) methods

Liquid penetrant, ultrasonic, eddy current and X-radiographic techniques were optimized and applied to the evaluation of 2219-T87 aluminum alloy test specimens in integrally stiffened panel, and weld panel configurations. Fatigue cracks in integrally stiffened panels, lack-of-fusion in weld panels, and fatigue cracks in weld panels were the flaw types used for evaluation. A 2319 aluminum alloy weld filler rod was used for all welding to produce the test specimens. Forty seven integrally stiffened panels containing a total of 146 fatigue cracks, ninety three lack-of-penetration (LOP) specimens containing a total of 239 LOP flaws, and one-hundred seventeen welded specimens containing a total of 293 fatigue cracks were evaluated. Nondestructive test detection reliability enhancement was evaluated during separate inspection sequences in the specimens in the 'as-machined or as-welded', post etched and post proof loaded conditions. Results of the nondestructive test evaluations were compared to the actual flaw size obtained by measurement of the fracture specimens after completing all inspection sequences. Inspection data were then analyzed to provide a statistical basis for determining the flaw detection reliability

Sensors for ultrasonic nondestructive testing (NDT) in harsh environments

In this special issue of Sensors, seven peer-reviewed manuscripts appear on the topic of ultrasonic transducer design and operation in harsh environments: elevated temperature, high gamma and neutron fields, or the presence of chemically aggressive species. Motivations for these research and development projects are strongly focused on nuclear power plant inspections (particularly liquid-sodium cooled reactors), and nondestructive testing of high-temperature piping installations. It is anticipated that we may eventually see extensive use of permanently mounted robust transducers for in-service monitoring of petrochemical plants and power generations stations; quality control in manufacturing plants; and primary and secondary process monitoring in the fabrication of engineering materials

Nondestructive testing - NDT: Amphitheater in Pula

Zahvaljujući nerazornim metodama ispitivanja, NDT, moguće je ispitivati objekte od povijesnog značaja i time stvarati jasniju predodžbu o stvarnom stanju njihove konstrukcije. Sva ispitivanja je potrebno provesti uz što manje oštećivanja postojeće strukture te je stoga potrebno vrlo pažljivo odrediti vrstu i obim zahvata. U provedbi ispitivanja koriste se dinamičke probe, statičke probe, tehnička dijagnoza pomoću rezultata ispitivanja NDT metodama i NDT monitoringa konstrukcije. Pomoću nerazornih metoda kontrole mogu se utvrditi na samom objektu svi potrebni parametri za pouzdanije i sigurnije projektiranje sanacije. NDT monitoring koji omogućuje kontinuirano praćenje ponašanja konstrukcij može započeti prije sanacije, trajati tijekom i nakon izvedene sanacije u provedbi kontrole izvedenih radova. Dinamičke karakteristike konstrukcije daju realno stanje objekta u fazi eksploatacije. One se određuju eksperimentalno bilježenjem funkcije reagiranja konstrukcije na određenu pobudu kao što je u konkretnom slučaju cestovni promet, zračni promet, utjecaj vjetra i glazbene manifestacije. U svrhu riješevanja ove problematike potrebno je izvršiti snimanje utjecaja vibracija navedenih pobuda. U ispitivanju konstrukcije Arene nerazornim metodama najčešće se primjenjuje magnetska metoda, ultrazvučna metoda ispitivanja, georadar, itd., NDT monitoring konstrukcije, snimanje morfologije nosećih zidova i temelja, te mjerenje napona u zidanoj konstrukciji. Temeljem rezultata ispitivanja dobivaju se potrebne informacije na temelju kojih će se izraditi projekt sanacije konstrukcije Arene. To je vrlo složen problem u čijem rješavanju sudjeluju stručnjaci raznih profila, arheolozi, restauratori, povjesničari umjetnosti te arhitekti i građevinari-statičari koji nastupaju često sa suprotnih početnih pozicija, ali uz rezultate NDT ispitivanja ostvaruju postavljeni cilj, a to je sigurnost građevine.Thanks to non-destructive testing (NDT), it is possible to test the objects of historic significance and thus build up a clearer picture of their current condition. For the purposes of recovery these data are invaluable. Dynamic examination, static examination, technical diagnosis based on the NDT results and NDT monitoring of the structure of an object can determine all necessary parameters on the object, which is crucial for more reliable and safer design of the recovery. NDT monitoring enables continuous supervision of the structure; it can start before the recovery, take place during and after the recovery and has been carried out within the framework of controlling of the performed work. Dynamic characteristics of the structure provide the information on the real condition of an object in the phase of exploitation. They can be experimentally measured by recording the response of the structure to the specific excitation, such as, in this case, road traffic, air traffic, influences of wind and music festivals. With the aim to tackle these issues, it is necessary to undertake the activities in recording of the influence of vibrations caused by named excitation of the load-bearing walls morphology and of the foundation morphology using NDT methods (it is common to use MT, UT, georadar etc.). Information provided, based on the results of testing, are necessary for this very complex problem. Many experts involved, such as archeologists, restoration teams, art historians, architects and construction workers had starting perspective often different, but with joint activities and NDT results they reach the same goal and that is the safety of the structure and preservation of a centuries-old building