Applying SMT Solvers to the Test Template Framework

The Test Template Framework (TTF) is a model-based testing method for the Z notation. In the TTF, test cases are generated from test specifications, which are predicates written in Z. In turn, the Z notation is based on first-order logic with equality and Zermelo-Fraenkel set theory. In this way, a test case is a witness satisfying a formula in that theory. Satisfiability Modulo Theory (SMT) solvers are software tools that decide the satisfiability of arbitrary formulas in a large number of built-in logical theories and their combination. In this paper, we present the first results of applying two SMT solvers, Yices and CVC3, as the engines to find test cases from TTF's test specifications. In doing so, shallow embeddings of a significant portion of the Z notation into the input languages of Yices and CVC3 are provided, given that they do not directly support Zermelo-Fraenkel set theory as defined in Z. Finally, the results of applying these embeddings to a number of test specifications of eight cases studies are analysed.Comment: In Proceedings MBT 2012, arXiv:1202.582

Werkstoffprüfung mit neuen Sensoren

Die zerstörungsfreie Werkstoffprüfung (ZfP) entwickelt sich methodisch und technisch entsprechend den Prüfanforderungen. Neue Werkstoffe, der Bedarf an quantitativen Prüfergebnissen, das Überwachen von Herstellungsprozessen in Echtzeit sowie die Prüfung in der Mikro- und Nanotechnik stellen Herausforderungen dar, die neue physikalische Prüfmethoden und eine effiziente Datenauswertung erfordern. Schwerpunkte bestehen dabei in quantitativen Fehlerbilddarstellungen bei hohen Prüfgeschwindigkeiten mit Hilfe von Röntgen- und Ultraschallsensoren, in der Prozesskontrolle von neuen Fügeverbindungen mit Wirbelstrom, der Prüfbarkeit von Leichtbauwerkstoffen mit Ultraschall und dem Einsatz von Mikrowellen- und Infrarotsensoren bei der Online-Qualitätsüberwachung von Beschichtungen

Theoretical Evaluation of Ultrasonic Scattering by Flaws in Anisotropic Media

Ultrasonic inspection plays an important role in numerous industrial fields. One of the prominent tasks is the determination of location, shape, size and orientation of defects. In isotropic materials, the location of reflectors can be inferred from time-of-flight measurements, angle of insonification and transducer position. In anisotropic media, however, such a procedure is aggrevated by several phenomena, which are the direction dependence of the ultrasonic velocities, the beam skewing effect and the modified radiation characteristics of flaws with respect to wave scattering. In this contribution, analytical relationships are presented for the scattering of ultrasound at defects in such media. Based on the mathematical formulation of Huygens' principle, these relationships are obtained for traction-free scatterers using Krichhoff's approximation. Asymptotic evaluation yields explicit expressions, which are further incorporated in the Generalized Point Source Synthesis method. Numeri cal results are obtained for rectangular and circualr reflectors, selected to compare with notches and flat-bottomed holes, respectively. Evaluation is performed in view of the radiation characteristics of these defects, conside ring (quasi-) longitudinal wave scattering in transversely isotropic weld material. Also, the elaborated relationships have been applied to calculate echo dynamic curves in dependence of transducer position for pulse-echo technique. Good comparison with experimental results has been obtained

Phased-Array-Optimierung für isotrope und anisotrope Strukturen

In vielen Bereichen der Ultraschall-Prüfung, insbesondere bei der Prüfung von dispersiven Materialien wie etwa austenitischem Stahl, kommen Winkelprüfköpfe zur Anwendung. Ausgelegt für den Sende-Empfangs- oder Impuls-Echo-Betrieb, können die Eigenschaften dieser Prüfköpfe noch verbessert werden, indem sie als Phased-Arrays (PA) betrieben werden. Jedes einzelne der Prüfkopfelemente wird mit entsprechender Zeitverzögerung angesteuert, sodaß Form und Richtung des Schallfeldes in einem weiten Bereich kontrollierbar sind. Neben Winkelprüfköpfen werden auch planare Anordnungen sowie elektromagnetische Ultraschall(EMUS)-Wandler als PAs betrieben. Dieser Beitrag beschreibt die Modellierung und Optimierung verschiedener Phased-Array-Konfigurationen mittels Generalisierter Punktquellensynthese (GPSS)

Integrierte automatische zerstörungsfreie Prüfung als Werkzeug der Qualitätssicherung in der Prozeß- und Qualitätssteuerung

Der Beitrag stellt das Methodenpotential der zerstörungsfreien Prüfung für die Integration in der Qualitätssicherung dar. Sowohl in den Entwicklungslabors der Industrie beim Design neuer Werkstoffe und Produkte mit funktionalen Eigenschaften, als auch im Prozeß liefert die zerstörungsfreie Prüfung Informationen und Meßwerte, die sich in Qualitätsmerkmale übersetzen lassen. Es werden Beispiele für automatisierte Qualitätsprüfungen an Halbzeugen und im Prozeß vorgestellt

Artificial Neural Network for On-Line Eddy Current Testing

Eddy current test (ECT) is affected by a large number of influencing parameters such as lift-off, variations in geometry, electrical conductivity, magnetic permeability, surface condition etc. [1]. To carry out meaningful ECT and evaluation, it is essential to eliminate or reduce the influence of unwanted parameters. When the number of unwanted parameter is one, its affect can be eliminated using single frequency eddy currents, for example, by rotating the phase of the signal along one of the impedance axes, abscissa in general and taking measurement along the other axis, i.e. the ordinate. However, in actual practice, the influencing parameters are more than one and defect detection and characterisation in their presence becomes rather difficult using single frequency. For example, the popular application of ECT of heat exchanger tubes, detection of defects under support plates and in the presence of probe wobble, is rather difficult using single frequency method.</p

NDT aided production

Production/Process Integrated Non Destructive Testing (NDT) Systems are increasingly becoming a part of automated production environments. This is being driven by a combination of low cost and higher quality requirements. Integrated process and condition monitoring by NDT is an accepted procedure for early diagnosis of irregular process conditions followed by feed back control and optimization. Market Research has forecasted that these process-integrated NDT systems will record double-digit growth rates over the coming years. The paper basically describes the requirements of industry and reports on the progress of NDT in this field. The emphasis is mainly on discussing case studies from metal manufacturing and machinery building, i.e. automotive and supplying industries