InformaApp - Publikationen

DOI: 10.1007/s11249-013-0107-0

Zeitschriftenartikel

K. Poulios, G. Svendsen, Jochen Hiller, P. Klit

Coefficient of Friction Measurements for Thermophastics and Fibre Composites Under Low Sliding Velocity and High Pressure

Tribology Letters, vol. 51, no. 2, pp. 191-198

2013

Friction materials for typical brake applications are normally designed considering thermal stability as the major performance criterion. There are, however, brake applications with very limited sliding velocities, where the generated heat is insignificant. In such cases it is possible that friction materials which are untypical for brake applications, like thermoplastics and fibre composites, can offer superior performance in terms of braking torque, wear resistance and cost than typical brake linings. In this paper coefficient of friction measurements for various thermoplastic and fibre composite materials running against a steel surface are presented. All tests were carried out on a pin-on-disc test-rig in reciprocating operation at a fixed sliding speed and various pressure levels for both dry and grease lubricated conditions. Moreover, a generic theoretical framework is introduced in order to interpret the changes of friction observed during the running-in phase.

DOI: 10.1016/j.procir.2013.08.022

Zeitschriftenartikel

P. Müller, A. Cantatore, J. Andreasen, Jochen Hiller, L. Chiffre

Computed Tomography as a Tool for Tolerance Verification of Industrial Parts

Procedia CIRP, vol. 10, pp. 125-132

2013

Digital Fraunhofer AWZ CTMT Maschinenbau und Mechatronik

Computed tomography (CT) is becoming an important technology for industrial applications, enabling fast and accurate control of manufactured parts. In only a few minutes, a complete 3D model of a part may be obtained, allowing measurements of external and internal features. This paper presents results of tolerance verification of a plastic housing for an insulin pen manufactured by Novo Nordisk A/S. Calculation of measurement uncertainties was taken into account in decision making regarding the specified tolerance limits. Variables in terms of CT systems, data sets, and evaluation software are considered in this study.

Zeitschriftenartikel

Jochen Hiller, L. Reindl

A computer simulation platform for the estimation of measurement uncertainties in dimensional X-ray computed tomography

Measurement, vol. 45, no. 8, pp. 2166-2182

2012

DOI: 10.1016/j.measurement.2012.05.030

Vortrag

Systematic Errors in Dimensional X-ray Computed Tomography

Maletekniske Dage, Taastrup, Dänemark

2012

DOI: 10.1088/0957-0233/23/8/085404

Zeitschriftenartikel

Jochen Hiller, M. Maisl, L. Reindl

Physical characterization and performance evaluation of an x-ray micro-computed tomography system for dimensional metrology applications

Measurement Science and Technology, vol. 23, no. 8

2012

This paper presents physical and metrological characterization measurements conducted for an industrial x-ray micro-computed tomography (CT) system. As is well known in CT metrology, many factors, e.g., in the scanning and reconstruction process, the image processing, and the 3D data evaluation, influence the dimensional measurement properties of the system as a whole. Therefore, it is important to know what leads to, and what are the consequences of, e.g., a geometrical misalignment of the scanner system, image unsharpness (blurring), or noise or image artefacts. In our study, the two main components of a CT scanner, i.e. the x-ray tube and the flat-panel detector, are characterized. The contrast and noise transfer property of the scanner is obtained using image-processing methods based on linear systems theory. A long-term temperature measurement in the scanner cabinet has been carried out. The dimensional measurement property has been quantified by using a calibrated ball-bar and uncertainty budgeting. Information about the performance of a CT scanner system in terms of contrast and noise transmission and sources of geometrical errors will help plan CT scans more efficiently. In particular, it will minimize the user's influence by a systematic line of action, taking into account the physical and technical limitations and influences on dimensional measurements.

Beitrag (Sammelband oder Tagungsband)

P. Müller, Jochen Hiller, A. Cantatore, M. Bartscher, L. Chiffre

New reference object for Metrological performance testing of industrial CT systems

Proceedings of the 12th euspen International Conference (Juni 2012, Stockholm, Schweden)

2012

Vortrag

P. Müller, Jochen Hiller, A. Cantatore, M. Bartscher, L. Chiffre

Investigation on the influence of image quality in X-ray CT metrology

Conference on Industrial Computed Tomography (ICT), Wels, Österreich

2012

Vortrag

Evaluation strategies in CT scanning

CT Conference, Kgs. Lyngby, Dänemark

2012

Beitrag (Sammelband oder Tagungsband)

K. Poulios, G. Svendsen, Jochen Hiller, P. Klit

Coefficient of Friction Measurements for Thermoplastics and Fiber Composites under Low Sliding Velocity and High Pressure

Proceedings of the 15th Nordic Symposium on Tribology 2012 (NordTrib, Trondheim, Norwegen)

2012

DOI: 10.1051/ijmqe/2012011

Zeitschriftenartikel

P. Müller, Jochen Hiller, A. Cantatore, L. Chiffre

A study on evaluation strategies in Dimensional X-ray computed tomography by estimation of measurement uncertainties

International Journal of Metrology and Quality Engineering, vol. 3, no. 2, pp. 107-115

2012

Computed tomography has entered the industrial world in 1980’s as a technique for non-destructive testing and has nowadays become a revolutionary tool for dimensional metrology, suitable for actual/nominal comparison and verification of geometrical and dimensional tolerances. This paper evaluates measurement results using different measuring strategies applied in different inspection software packages for volume and surface data analysis. The strategy influence is determined by calculating the measurement uncertainty. This investigation includes measurements of two industrial items, an aluminium pipe connector and a plastic toggle, a hearing aid component. These are measured using a commercial CT scanner. Traceability is transferred using tactile and optical coordinate measuring machines, which are used to produce reference measurements. Results show that measurements of diameter for both parts resulted in smaller systematic errors compared to distance and height measurements. It was found that uncertainties of all measurands evaluated on surface data were generally greater compared to measurements performed on volume data.

Zeitschriftenartikel

Jochen Hiller, L. Reindl

A computer simulation for the estimation of measurement uncertainties in dimensional X-ray computed tomography

Measurement, pp. 2166-2182

2012

Vortrag

CT scanning strategy - Prediction of image quality

Conference on Application of CT Scanning in Industry, Taastrup, Dänemark

2011

Vortrag

S. Reisinger, S. Kasperl, M. Franz, Jochen Hiller, U. Schmid

Simulation-Based Planning of Optimal Conditions for Industrial Computed Tomography

International Symposium on Digital Industrial Radiology and Computed Tomography, Berlin

2011

DOI: 10.1524/teme.2011.0137

Zeitschriftenartikel

Jochen Hiller, T. Fuchs, S. Kasperl, L. Reindl

Einfluss der Bildqualität röntgentomographischer Abbildungen auf Koordinatenmessungen

Grundlagen, Messungen und Simulationen

tm - Technisches Messen, no. 7/8, pp. 334-347

2011

Die industrielle Computertomographie (CT) findet in der dimensionellen Messtechnik zunehmend Akzeptanz. Allerdings ist noch wenig über den konkreten Einfluss verschiedener Systemkomponenten, physikalischer Störgrößen oder Bildverarbeitungsschritte auf dimensionelle CT-Messungen bekannt. In diesem Beitrag werden physikalische Bildgütemerkmale zur Beurteilung der Bildqualität in der CT vorgestellt und mittels Computersimulationen der Einfluss der Rekonstruktionsbildgüte auf Koordinatenmessungen untersucht.

Beitrag (Sammelband oder Tagungsband)

P. Müller, Jochen Hiller, A. Cantatore, L. Chiffre

Investigation of measuring strategies in computed tomography

Proceedings of the International Conference on Advanced Manufacturing Engineering (Newstech, Brno, Tschechische Republik)

2011

Vortrag