Non destructive

The chromatogram can finally be used as the series of bands or zones of components or the components can be eluted successively and then detected by various means (e.g. thermal conductivity, flame ionization, electron capture detectors, or the bands can be examined chemically). If the detection is non-destructive, preparative scale chromatography can separate measurable and useful quantities of components. The final detection stage can be coupled to a mass spectrometer (GCMS) and to a computer for final identification. 

A new, non destructive method has been developed for testing high strength bolts which is based on measuring the magnetic stress on the head of a bolt. The forces originating in the body of the bolt can be determined in this way since these forces are proportional to the stress state in the head of the bolt. 

The publication of interstate Standard GOST 30415-96" Steel. Non-destructive inspection of mechanical properties and microstructure of metal products by magnetic method" - is the long-expected event for works laboratories and development engineers of non-destructive test means. 

The basic condition of the Standard application - the availability of stable coupled probabilistic or the multiple probabilistic relations between then controlled quality indexes and magnetic characteristics of steel. All the probabilistic estimates, used in the Standard, are applied at confidence level not less than 0,95. General requirements to the means of control and procedure of its performance are also stipulated. Engineers of standard development endeavoured take into consideration the existed practice of technical control performance and test at the enterprises that is why the preparation of object control for the performance of nondestructive test can be done during the process of ordinary acceptance test. It is suggested that every enterprise is operated in correspondence with direct and non-destructive tests, obtained exactly at it, for detailed process chart and definite product type, however the tests have long since been performed after development of the Standard displayed that process gives way to unification. 

GOST 30415 specifies plans for inspection the products of different types and sets formulae for calculation of inspected numbers while applying magnetic inspection. The procedure of random inspection is predetermined to check the authenticity of the correlated relation usage and regulations are introduced to enter data file of non-destructive and parallel tests. 

Not to overload the Statidard, three supplements are predetermined for it. The Supplement A (compulsory ) with the list of statistics is due to compulsory determination by non-destructive magnetic method of mechanical properties test. This Supplement provided the possibility to set the reasonable compromise between two opposite tendencies -to simplify utmost a body of mathematics or, on the contrary, to complicate it to such extent that it becomes inaccessible. 

The Supplement B (reference) contains a description of the process to render an automatic construction of mathematical models with the application of electronic computer. The research work of the Institute of the applied mathematics of The Academy of Sciences ( Ukraine) was assumed as a basis for the Supplement. The prepared mathematical model provides the possibility to spare strength and to save money, usually spent for the development of the mathematical models of each separate enterprise. The model provides the possibility to execute the works standard forms and records for the non-destructive inspection in complete correspondence with the requirements of the Standard. 

It is known that diagram " Stress - Deformation " ( SD) is more vividly specifying the current metalwork condition. However, such diagram can be obtained only by destructive testing. The suggested non-destructive magnetic method in the report for the evaluation of SD condition and for the prediction of residual resource of metalwork, where the measurement of coercive force (CF) is assumed as a basis. 

CEN TC 138 (Non-destructive Testing) WG 7 (Acoustic Emission) Draft for General Principals"... 

F. Cattaneo, C. De Michelis, S. Ghia, G.M.Piana "AEBIL a new acoustic emission system for on-line structural integrity monitoring of critical power plant components" to be presented at the 7th European Conference on Non-Destructive Testing, Copenhagen, 26-29 May 1998. 

Lately, polymeric composite materials have found a wide recognition thanks to their unique qualities /1,2/. But use of the materials for construction, is limited, because lack of reliable diagnostic facilities. The non-destructive control method (NC), based on the acoustic emission phenomenon (AE), might offer a prospective solution to the situation. 

Increasing mechanisation and automatisation of non-destructive inspection procedures lead to an increasing amount of data that is acquired in a short amount of time. This in turn creates a need for reliable automatic or automated data interpretation techniques. 

Within the framework of the ANDES (Automatic Non-Destructive Evaluation System) at TNO Institute of Applied Physics two prototype applications have been developed for automated NDT data interpretation - both using the CBR methodology. 

Munns, G.A. Georgiou, Non-destructive testing methods for adhesively bonded joint nspection - a review, INSIGHT, Vol 37, No 12, Dec 1995, pp 941-952... 

Andrews, J. Blanchard, T. Stepinski, L. Ericsson, Ultrasonic spectroscopy for NDT, Presented at Int. Symp. Non-Destructive Testing in Civil Engineering (NDT-CE), Berlin, 1995... 

Eddy-current non-destructive evaluation is widely used in the aerospace and nuclear power industries for the detection and characterisation of defects in metal components. The ability to predict the probe response to various types of defect is highly valuable since it enables the influence of particular parameters to be studied without recourse to costly and time consuming experiments. The solution of forward problems is also essential in the process of inverting experimental data. 

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