This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License Newcastle University ePrints-eprint.ncl.ac.uk Koulin G, Zhang J, Frazer RC, Shaw BA, Sewell I. A new profile roughness measurement approach for involute helical gears. Measurement Science and Technology 2017

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International licence Newcastle University ePrints-eprint.ncl.ac.uk Koulin G, Reavie T, Frazer R, Shaw BA. Economic method for helical gear flank surface characterisation.

With improving gear design and manufacturing technology, improvement in metrology is necessary to provide reliable feedback to the designer and manufacturer. A recommended gear roughness measurement method is applied to a micropitting contact fatigue test gear. The development of wear and micropitting is reliably characterised at the sub-micron roughness level. Changes of the localised surface texture features are revealed and are related to key gear meshing positions. The application of the recommended methodology is shown to provide informative feedback, to the gear designer, in reference to the fundamental gear coordinate system which is used in gear performance simulations such as tooth contact analysis.

There is a growing need for cheaper, more sustainable energy sources and this calls for optimisation of energy harnessing systems. Offshore wind energy has been highlighted as one of the more promising energy sources and in this application, the foundation structure for a typical installation contributes significantly to the overall levelised cost of energy. With this in mind, a faceted monopile foundation design and the review of its critical evaluation is presented. This type of design lends itself well to mass production and upscaling, both factors seen to reduce the overall cost of gathered energy. The evaluation of the design is performed through comparison with a conventional, circular monopile design. The comparison is undertaken using conventional design criteria as outlined by the DNV standards body. A finite element model was used to evaluate the structural performance of the designs. It is shown that the faceted design has a higher fatigue resilience than the conventional round design. Also, the fatigue damage caused to the monopile during pile driving installation is estimated from the conducted scaled down test where a series of strain gauge signals were collected to allow for stress measurement at specific points of interest. The feasibility of the proposed faceted monopile design is supported based on this critical evaluation.

Waviness is an important surface parameter in gears and the capability of measurement machines to capture this is largely unknown. The wavelengths of interest relate to transmission error (TE) and contact stress, both of which depend on a pair of gears and their geometry. TE directly relates to the noise and vibration during operation and contact stress drives failure of gear teeth. Accurately capturing the waviness wavelengths related to these parameters is consistent to geometric product specification (GPS) which requires: (i) specification of functional parameters (ii) description of how to measure each parameter and (iii) evaluation of parameter measurement uncertainty. A GPS compliant method is outlined with verification by two workpiece-like artefacts; one gear finished by surface grinding and one finished by a superfinishing process. The method evaluates a gear measurement machine (Klingelnberg P65) against a reference surface measurement instrument (Talysurf Intra 50). Results show that waviness measurement depends on measurement speed, probe choice, and strategy relating to different gear manufacturing methods. Actions to improve the characterisation method, such as including other key performance indicators and quantification of uncertainties, are suggested.