Nondestructive inspection,

We have seen a variety of manufacturing processes, but certainly not all possible processes. Those processes would likely be used to produce many different parts with different characteristics and purposes. The diversity of parts might well be combined to form a single structural part such as a wirig n Figure 1-19. After each process, every part is nondestructively inspected. 

New casing is delivered free of injurious defects. Various nondestructive inspection services have been employed by users to assure that the desired quality of casing is being run. 

New tubing is delivered free of injurious defects as defined in API Standard 5A, SAC and SAX, and within the practical limits of the inspection procedures therein prescribed. Some users have found that, for a limited number of critical well applications, these procedures do not result in casing sufficiently free of defects to meet their needs for such critical applications. Various nondestructive inspection services have been employed by users to assure that the desired quality of tubing is being run. In view of this practice, it is suggested that the individual user ... 

Nondestructive evaluation, also termed nondestructive testing or nondestructive inspection, is extensively used in weld testing (14). Nondestructive tests do no impair the serviceability of the material or component under stress. The most widely used tests for evaluation of welds are liquid penetrant, magnetic particle, ultrasonics, and radiography. Acoustic-emission tests are increasingly used. Nondestructive tests detect and characterize, in terms of size, shape, and location, the various types of weld discontinuities that can occur. 

Inspection is usually done by nondestructive techniques. This is usually known as nondestructive examination (NDE). The general term nondestructive evaluation describes the various terms used such as nondestructive inspection (NDI), nondestructive testing (NDT) and nondestructive examination (NDEx). Some of the aspects or purpose of these techniques involve detection and evaluation of flaws, leaks, dimensions, location (position), microstructures, mechanical properties and stress. 

In reality, the identification of one or more forms of corrosion requires visual observation, nondestructive inspection methods, optical microscopic examination, and sometimes electron scanning microscopy, etc. The first study of the corrosion appearance of a case should divide corrosion into uniform and localized corrosion. Localized corrosion can be further identified as macroscopic or microscopic local corrosion. Microscopic attack refers to a minute amount of dissolved metal, accompanied by considerable damage, before the phenomenon becomes visible to the naked eye. 

James K. Drennen and John D. Kirsch, U.S. Patent No. 5,750,996, May 12, 1998. Apparatus for Nondestructive Inspecting a Coated Article and Associated Method. ... 

Busse, G. Eyerer, P. Thermal wave remote and nondestructive inspection of polymers. Appl. Phys. Lett. 1983, 43, 355-357. 

The minimum fracture toughness required would depend on the yield strength of the material, and the expected crack size, which is to be set by the efficacy and fidelity of regularly scheduled nondestructive inspections. 

The lower hmit of integration (at or ai) is usually defined on the basis of nondestructive inspection (NDl) capabilities, or on prior inspection the upper limit is defined by fracture toughness or a predetermined allowable crack size that is consistent with inspection requirements (a/ or 2)- Equations (7.5) and (7.6) may be rewritten in terms of the stress intensity factor K ... 

The service life is then reduced to about 6 x 10 cycles. This example illustrates the importance of avoiding, or reducing the size of initial defects in the structure, and the need for improved methods for nondestructive inspection. 

LIQUID PENETRANT INSPECTION - A type of nondestructive inspection that locates discontinuities that are open to the surface of a metal by first allowing a penetrating dye or fluorescent liquid to infiltrate the discontinuity, removing the excess penetrant, and then applying a developing agent that causes the penetrant to seep back out of the discontinuity and register as an indication. 

The inspection task itself is classified in aviation as either visual inspection or nondestructive inspection. Regulatory bodies have issued formal descriptions of both of these tasks (e.g., Bobo 1989, for the FAA), and both have somewhat different characteristics in aviation... 

Nondestructive inspection (NDI) includes a set of techniques to enhance the ability to detect small and/or hidden malfunctions. One set of NDI techniques is those that enhance what is essentially still a visual inspection task, such as X ray, fluorescent particle, magnetic particle, or D Sight. They show cracks that are very small (fluorescent particle) or hidden within other structures (X ray). Apart from the steps necessary to ensure a good image, they have many of the human interface characteristics of visual inspection. The other set of NDI techniques is focused on specific malfunctions in specific locations, such as eddy current and ultrasound. For this reason, they are useful only for detection of malfunctions already predicted to exist. In practice, such NDI techniques are much more procedur-alized than visual inspection or NDI techiriques, which contain a human visual inspection component. 

Over the past two decades there have been several studies of human reliability in aircraft structural inspection (Rummel et al. 1989 Spencer and Schurman 1995 Muigatroyd et al. 1994). AU of these to date have examined the reliability of nondestructive inspection (NDI) techniques, such as eddy current and ultrasonic technologies. 

Bobo, S. (1989), Communication and Transfer of Nondestructive Inspection Information, in/7 man Factors Issues in Aircraft Maintenance and Inspection—Information Exchange ami Communications, Second Federal Aviation Administration Meeting, Washington, DC. 

Crack length, which can be determined by nondestructive inspection techniques Levels of stress encountered in service... 

Vernon. S. N. (1987), Eddy current nondestructive inspection of graphite epoxy using ferrite cup core probes. Report NSWC-TR-87-148, Sept. 1987. Naval Surface Warfare Center. Silver Spring. MD. USA. 

Lord. R. J. (1985). In-service nondestructive inspection of fighter and attack aircraft. Materials Evaluation. May 1985, 43, 5, 133-739. 

Nondestructive testing (NDT), nondestructive inspection (NDI), and nondestructive evaluation (NDE) (collectively, NDT/I/E) are concerned with the techniques and measurements that provide data on the condition of the materials and stmcmres at the time of manufacturing and in-service. The NDT/I/E methods are, generally speaking, discrete inspections performed during manufacmre and at specified intervals or events during the service of a stmcture. 

As described above, an ultrasonic single-pulse response m the frequency domain was utilized to image the defects in a technologically important polymeric composite of CFRP. This imaging technique provides useful information about the internal structure of the CFRP sample, and is likely to become a powerful method for the nondestructive inspection of many polymeric composites. 

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