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Non Destructive Testing and Evaluation

Non Destructive Testing and Evaluation

Visual Inspection is a nondestructive testing technique that provides a means of detecting and examining a variety of surface flaws, such as corrosion, contamination, surface fmish, an[r]

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Pulsed Eddy Current Non-destructive Testing and Evaluation: A Review

Pulsed Eddy Current Non-destructive Testing and Evaluation: A Review

Abstract Pulsed eddy current (PEC) non-destructive test- ing and evaluation (NDT&E) has been around for some time and it is still attracting extensive attention from researchers around the globe, which can be witnessed through the reports reviewed in this paper. Thanks to its richness of spectral components, various applications of this technique have been proposed and reported in the lit- erature covering both structural integrity inspection and material characterization in various industrial sectors. To support its development and for better understanding of the phenomena around the transient induced eddy currents, attempts for its modelling both analytically and numeri- cally have been made by researchers around the world. This review is an attempt to capture the state-of-the-art development and applications of PEC, especially in the last 15 years and it is not intended to be exhaustive. Future challenges and opportunities for PEC NDT&E are also presented.
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EVALUATION OF CONCRETE STRENGTH OF IN-SERVICE BUILDINGS BY NON- DESTRUCTIVE TESTING TECHNIQUES

EVALUATION OF CONCRETE STRENGTH OF IN-SERVICE BUILDINGS BY NON- DESTRUCTIVE TESTING TECHNIQUES

Non-destructive testing (NDT) as the name implies refers to a test that does not impair the intended performance of the element, member or structure under investigation. These techniques have been grown during recent years especially in the case of construction quality assessment. The main advantage of these tests is to avoid the concrete damage or the performance of building structural components. Additionally their usage is simple and quick. These techniques have their own advantages as well as limitations, when compared to conventional strength estimation and damage detection tests. By using these Non destructive tests has been performed to assess the compressive strength of concrete employed in the structures. In this project both rebound hammer method and ultrasonic pulse velocity method are used to determine the compressive strength of in-service buildings in RGMCET campus Project Objective
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Performance Demonstration of Non-Destructive Testing Methods

Performance Demonstration of Non-Destructive Testing Methods

Comparing the described non-destructive testing methods repetition measurements have been carried out. The examinations demonstrate that all these methods could be applied for localising parts of smaller thickness and tendon ducts. With the used non-destructive testing methods highly accurate measurements with small deviations within a few millimetres are possible, if scanning methods are used. On single point measurements the inaccuracy is in the order of about 1 cm. The accuracy of these methods can be deduced by examinations on structural elements with reference specimens, like the “large concrete slab” LCS. A comprehensive evaluation including the quantification of ungrouted ducts and the localisation of honeycombs will be reported later.
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Abstract This paper reports non-destructive testing conducted

Abstract This paper reports non-destructive testing conducted

Abstract— This paper reports non-destructive testing conducted on dissimilar friction stir welds between 5754 aluminium alloy and C11000 copper. The Friction stir welds of 5754 aluminium alloy and C11000 copper were produced at different tool rotational speeds and feed rates. The tool rotational speed was varied between 600 and 1200 rpm while the feed rate was varied between 50 and 300 mm/min. The visual inspection and the x-ray radiographic testing techniques were employed to conduct the tests; these tests were conducted on the welds to ascertain the joint integrity before characterization to have an idea of the quality of the welds. No visual defects were observed on all the welds considered but the x-ray radiography technique revealed the presence of wormhole defects and discontinuities in some of the welds. It was found that the welds produced at 950 rpm with varied feed rates were the best quality welds produced and this was substantiated with the microstructural evaluation of the joint interface. It was found that these welds have good mixing and metallurgical bonding at the interfaces.
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Structural Health Monitoring By Using Damage Evaluation Techniques

Structural Health Monitoring By Using Damage Evaluation Techniques

ABSTRACT: Structural health monitoring is a monitoring process of damage assessment in ant structure such as bridges, culverts, tall buildings, railway lines, underground pipeline etc. damage refers to change in characteristics properties of concrete which includes cracks, spelling of concrete, member separation, and fractures. etc. Due to the overloading lack of maintenance, fire or any environmental affects which causes the failure of structure. To assess the present condition, homogeneity of concrete and critical stage of structure after occurring of any environmental or man- made calamities, damage evaluation techniques has to be adopted. Damage evaluation techniques non-destructive testing methods such as rebound hammer, half-cell potential meter, carbonation measurement and ultrasonic pulse velocity test are adopted. The data’s is collected by adopting multiple NDT methods at various locations of structure and by graphical and tabular analysis and data interpretation.. Based on the graphical and mathematical interpretation from wireless sensor methodology and NDT testing, the proper rehabilitation and repair measures adopted to the structure to strengthening the life and health of structure, in case of damage condition. These are also some implementation takes place in structure design for future point of view to avoid such damages.
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NON DESTRUCTIVE TESTING TECHNIQUES FOR RISK BASED INSPECTION

NON DESTRUCTIVE TESTING TECHNIQUES FOR RISK BASED INSPECTION

Although Alternating Current Field Measurements and ultrasonic phased array techniques provide innovative means of non destructive evaluation, the accuracy of the RBI program still depends on the inspection reliability. The inspection data should reveal the location of a defect, and the length and depth of the crack. The probability of detection (POD) is a statistical measure of the success of an inspection, whereas the probability of sizing (POS) provides an indication of sizing accuracy. In this section, the implications of POD and POS on an RBI program are briefly discussed.
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GUIDELINES ON NON-DESTRUCTIVE TESTING OF BRIDGES

GUIDELINES ON NON-DESTRUCTIVE TESTING OF BRIDGES

There are several antenna manufacturers, antenna types, signal pre- and post- setting options; operating frequencies software packages, etc. to consider for a specific application within the engineering and construction industry, geological, environmental and/or archaeological fields. Each radar system must be designed to meet the objective(s) of a given project. For concrete evaluation studies, there are several options available – all of which have certain advantages and disadvantages. For the evaluation of various concrete structures, which include streets/highways, parking lots, bridge decks, pools, tilt wall panels, sidewalks, various foundation systems and retaining walls, a versatile and highly portable radar system with a ground coupled, monostatic antenna is suitable. However, for specialized projects, such as road condition evaluation, an air launched (horn) antenna is commonly used due to the efficient data collection, characteristic of this antenna. Currently, GPR data can be collected with this air- launched antenna at highway speeds.
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Non-destructive modulus testing and performance evaluation for asphalt pavement reflective cracking mitigation treatments

Non-destructive modulus testing and performance evaluation for asphalt pavement reflective cracking mitigation treatments

The modulus of the rubblized layer and rock interlayer cannot be evaluated directly because these layers are be- neath the asphalt overlay. In addition, intact samples can- not be obtained for rubblized PCC pavement and rock interlayer, in most cases, retrieved are unrepresentative samples and samples are lack of cohesiveness to hold themselves as a core. The most practical approach for the modulus estimation of the underlying treated layer is through non-destructive testing using the Falling Weight Deflectometer (FWD) and geophysical Surface Wave Method (SWM). In this study, FWD and SWM tests were employed to measure the modulus of pavement structures after reflective cracking mitigation treatments. The FWD test applies a transient load pulse on a pavement surface to simulate the magnitude and duration of a single rolling wheel load. The resulting pavement deflections at selected radial locations from the loading centre are measured by a series of sensors (e.g., geophones), from which deflection is obtained. The stiffness profile of the tested pavement site is back calculated by matching the FWD experimen- tal surface deflection to theoretical counterparts calculated for assumed stiffness profiles (FHWA, 2000). The FWD deflection data in this study was collected using a JILS-20 FWD by applying a step loading sequence of 40 kN. The geophone offsets were 203, 305, 457, 610, 914, 1219 and 1524 mm (8, 12, 18, 24, 36, 48 and 60 inches) away from the loading centre.
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Applications of microwaves in non-destructive testing

Applications of microwaves in non-destructive testing

Microwave assisted nondestructive (MA-NDT) evaluation techniques using a resonant microwave mode was presented. Such an evaluation system provides an on-line, volumetric, non-contact, non-intrusive and non-destructive monitoring feature. By comparing a microwave reflective spectrum during the production processes to the standard spectra, a computerized monitored system can be used to regulate the process-input parameters for proper adjustment and compensation. Such methodology can be used for on-line assessing and real-time evaluating product quality. Successful application of this technique depends largely on the database gathered, which can greatly reduce or eliminate products with defects generated during the manufacturing process.
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A CASE STUDY OF PROBLEM IDENTIFY IN MACHINING PROCESS BY NON DESTRUCTIVE TESTING FOR IMPROVING PRODUCT QUALITY

A CASE STUDY OF PROBLEM IDENTIFY IN MACHINING PROCESS BY NON DESTRUCTIVE TESTING FOR IMPROVING PRODUCT QUALITY

Non-destructive testing (NDT) is a wide group of analysis techniques used in science and industry to evaluate the properties of a material, component or system without causing damage. The terms Nondestructive examination (NDE), Nondestructive inspection (NDI), and Nondestructive evaluation (NDE) are also commonly used to describe this technology. Because NDT does not permanently alter the article being inspected, it is a highly-valuable technique that can save both money and time in product evaluation, troubleshooting, and research. Non- destructive Testing is one part of the function of Quality Control and is Complementary to other long established methods. By definition non-destructive testing is the testing of materials, for surface or internal flaws or metallurgical condition, without interfering in any way with the integrity of the material or its suitability for service.
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Ultrasound field measurement and modelling for non-destructive testing

Ultrasound field measurement and modelling for non-destructive testing

Weak bond evaluation in IC packaging with a typical structure of silicon / adhesives / lead-frame has been investigated in this chapter. Thermal-cycling was used to prepare samples with varied interfacial conditions, leading to an interfacial degradation that is gradual both temporally and spatially. A broadband spherically- focused transducer with a nominal centre frequency of 100 MHz was used in immersion mode, and the ultrasonic beam focused to a very small spot at the interfaces between the silicon and adhesive and between the adhesive and lead- frame. The interfacial condition over the area insonified by the focused beam can be considered uniform. Such a spherically-focused transducer has the capability to measure ultrasonic echoes of a specific interface condition at a point rather than an average over a larger area as would be obtained with a larger focal spot size. Therefore the measurements compare well with the predictions made by an interface spring model that is based on a uniform interfacial condition. An ultrasonic response for a specific interfacial condition rather than an average of a non-uniform interfacial condition has been obtained
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Aspects of thermography for non-destructive testing in mechanical maintenance

Aspects of thermography for non-destructive testing in mechanical maintenance

In non-destructive evaluation (NDE), IRT is divided into two categories, as passive and active thermography [2, 3 and 4]. Passive thermography is based on the acquisition of thermography images of the object under study without external heat supply [2, 5 and 6]. In some cases, the heating is caused by the radiation from the sun, moving machinery, endothermic or exothermic process etc., [2, 5, 7]. Active thermography is based on the use of an external energy source that enables the flow of heat waves in the material [3, 5]. The energy (not always heat) source varies according to the technique employed [2, 7]. So far the techniques employed are pulsed laser and flash lamps, mechanical vibrations, induction heater, acoustic wave excitation and microwaves [5, 8]. Infrared thermography provides the following advantages.
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Non Destructive Evaluation of Reinforced Concrete Frames

Non Destructive Evaluation of Reinforced Concrete Frames

Subcontinent due to its activeness seismically is vulnerable to earthquakes of different level. Extreme events of such type induce long term durability issues in the concrete structure which compromises the strength of the structures . So far, only visual observation or Non-destructive testing (NDT) technique is practiced to determine the extent of damage post a disaster. But this observation does not give us the complete details of the extent of damage. There is a dire need to develop an efficient technique to precisely model the damaged structure to have a deep insight into the mode of cracking and reason behind strength reduction or complete failure. An instrument was developed by Earnst Schmidt at the end of decade of 1950’s which works on a principle of rebound of the concrete’s surface. Strength judgement methods on the basis of the rebound of the surface a specimen were used in 1930’s[1]. This hammer works rebound from the surface of the metal. Hardness of the surface is given by stroking the surface with the hammer and rebound from the surface gives the hardness of the material’s surface [2]. Research work has been done to find relation among the destructive testing and rebound hammer test but reliability using this equipments is still a big issue. In one of the research, effort were made to provide possible solutions for developing relationship among the two values. Cubes of different mixes but almost of the same density were used by them. It was concluded that maturity, state of stress and moisture content have a strong influence on the test results. It was found that if such factors are not included in the test, there may be a variation of 70 percent among the field data and data obtained from RHT [3]. RHT alone is not that realiable to give a measure of the strengths of the sample. This test should be carried out with another NDT or destructive tests to give reliable results or find relation among the NDT and destructive testing [4] Research has been done using DIA on ninety six samples. Seventy two cylinders were used to find the tensile and compressive strength with different mixtures and contained dolomite and gravel as aggregate. Six vertical sections and eighteen horizontal sections were used for DIA of the samples. The horizontal section were driven from three section, that is top, centre and bottom while the vertical sections were extracted from the centre of the cylinders as shown in Fig 1 [5].
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Evaluation of Mechanical Properties of AA6082-T6 Aluminium Alloy Using Pulse & Non-Pulse Current GTAW Process

Evaluation of Mechanical Properties of AA6082-T6 Aluminium Alloy Using Pulse & Non-Pulse Current GTAW Process

ABSTRACT: The 6xxx aluminium alloys have found application in automotive structures, as they offer an attractive combination of strength, formability and corrosion resistance, surface properties and good weldability. To make effective use of the automated systems it is essential that a high degree of confidence be achieved in predicting the weld parameters to attain the desired mechanical strength in welded joints. In this research, AA 6082 welds are made with gas tungsten arc welding (GTAW) using AA 4043 filler wire with non-pulsed current and pulsed current at different pulse frequencies like 2 pulses/sec, 4 pulses/sec and 6 pulses/sec using precision TIG 375 welding machine. This report to investigates the weld quality through non destructive testing (NDT) to study the porosity and surface cracks and also evaluation of the mechanical properties like ultimate tensile strength (UTS), 0.2% yield strength (YS) and % of elongation using GTAW with non-pulsed current and pulsed current at different pulse frequencies were studied and also to find the weld joint efficiency of the weldments. From this investigation the pulsed current TIG welding produces the better mechanical properties compared to the other welding processes.
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Characterization of steel buildings by means of non-destructive testing methods

Characterization of steel buildings by means of non-destructive testing methods

Recording data in an existing building is a grueling task which has to be improved. The measurement equipment needs external electrical power supply and should be adapted to run with a battery to make it more handy, unless the devices themselves are quite small and handy, compare Fig. 3 and Fig. 4. Nevertheless, measurements have been made at the materials testing institute (MPA) of the University of Kaiserslautern as well as in exist- ing buildings like the Ceasarparkbrücke (Kaiserslautern), see Fig. 5, and a covered market (Frankfurt/Main), see Fig. 4. In the sequel, the data evaluated in Sect. 5 are those obtained in the lab test because the exact load situation is known, thus, we have structural as well as measured residuals for the evaluation of the techniques.
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Non destructive testing of solid propellant rocket motors

Non destructive testing of solid propellant rocket motors

Both of these failure modes are undesirable because they both locally increase the free surface to burn. This means that once the fire front has reached this spot, there is a sudden increase in free surface to burn, resulting in more combustion gases and a higher pressure inside the motor. If this pressure is too high, the engine could burst and explode. In reality, these (severe) cracks and debondings are not observed very frequently while assessing the propellant rocket motors of missiles still in use. Without indicators of failed propellant material, visible as cracks or debondings, it is hard to assess the state of the solid propellant material without sacrificing a missile and estimate the remaining lifespan of the missile. This means that ideally the non destructive tests should focus more on the material ageing and the change in material properties rather than look for cracks and debondings if one wants to assess the life expectancy of a propellant rocket motor.
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Virtual source aperture imaging for non-destructive testing

Virtual source aperture imaging for non-destructive testing

In recent years, the adoption of linear array transducers and the use of synthetic aperture imaging has expanded considerably for non-destructive testing, leading to the introduction of the full matrix capture data acquisition technique and the total focusing method. Based on the underlying principles of the synthetic aperture focusing technique, it is capable of producing higher resolution images, but at the cost of lower frame rates. For time-critical inspections, this paper outlines an alternative synthetic aperture method, termed virtual source aperture (VSA). To measure performance in terms of speed, full matrix capture, synthetic aperture focusing and the virtual source aperture are compared experimentally, where it is shown that the virtual source aperture offers rapid inspection times with images of good lateral resolution and signal-to-noise ratio.
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Ultrasonic non-destructive testing of adhesive bonded aluminum plates

Ultrasonic non-destructive testing of adhesive bonded aluminum plates

NDT should not be confused with non-destructive inspection (NDI). NDT means to examine whether there is a flaw in objects which the smaller ones are like on the ICs and the larger ones as the examples the oil tanks, aircraft body, flapperons, or oil tankers, of which their sizes and inner defect structures cannot be seen through. NDT can be applied to all types of material. The test includes visual testing, radiographic testing, ultrasonic testing, magnetic particle testing, liquid penetrant testing and eddy current testing. However, NDI includes the judgment whether it is safe when we continue to use the objects for certain time, or it is necessary to undergo treatment (repairing or refurbishing) which all depends on the results obtained by using NDT. In conclusion, the inspectors will decide and recommends whether the items are in good condition in certain period of time or need to be replaced immediately through NDI.
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NON-DESTRUCTIVE TESTING OF RC BEAMS MADE WITH PARTIAL REPLACEMENT OF COARSE AGGREGATES FROM DEMOLISHED CONCRETE EXPOSED TO FIRE

NON-DESTRUCTIVE TESTING OF RC BEAMS MADE WITH PARTIAL REPLACEMENT OF COARSE AGGREGATES FROM DEMOLISHED CONCRETE EXPOSED TO FIRE

Population growth particularly in city centers around the globe have forced the construction industry to build high rise structures in place of old and short height buildings. This on other hand led waste disposal crisis. An approach to reduce these crises is to reuse the demolishing waste in new construction. Therefore, this research work used 50% replacement of natural coarse aggregates with coarse aggregates from demolished concrete. Generally, quality of concrete is estimated by measuring its strength. Laboratory testing of strength is time consuming therefore, non-destructive test methods provide good alternative to destructive testing. In this research work rebound hammer tests are used to estimate the compressive strength of reinforced concrete beams made by 50% replacement of coarse aggregates with coarse aggregates from old demolished concrete. 48 RC beams are cast using normal and rich mix concrete. 12 beams are cast using all-natural aggregates to compare the results of proposed beams. After curing of 28-days in standard manner rebound hammer is used to measure the compressive strength of the beams, followed by exposing the beams to fire for 6- and 12-hours at 1000°C in purpose made oven. The comparison of results with control specimen shows that proposed beams has good fire resistance and can be used initially in areas of low load.
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