Development of Computational Analysis Criteria Based on Laser Sensor Device to Identify the Surface Status of Micro-structured Coatings for Aerospace Industry

Abstract

In 2009, the European Union decided that CO2 emissions on ship and aerospace industries must be reduced by 10% and 20% respectively. To fulfill these requirements, aerospace industries looking for new approaches to overcome this challenge and take technological gains. The use of bio-inspired micro-structured coatings, e.g.riblet structured based on shark skin; this is one of new technologies applied. In this context, quality control in manufacturing and maintenance of structured coatings is of extreme relevance specifically for aerospace industries to ensure the optimal surface structuring, to assist maintenance, to predict life time, and consequently to decide when to perform surface renewal. The mentioned requirements are met with an experimental fast sampling sensor setup using noncontacting laser probing. The theory behind the laser sensor device is based on Huygens-Fresnel diffraction theory combined with ray-tracing calculation methods. A computational tool was developed to perform analysis and treatment of output data provided by the laser sensor. This dissertation aims to present a methodology to evaluate the calculations implemented in this computational tool. It is used to interpret the obtained diffraction patterns, and as a tool to simulate the structured surface status from a given pattern. Thus, the software is developed to generate consistent information for analysis and decision-making regarding the surface structure and its maintenance. The software development is performed by using Object Oriented programming (OOP) and it is also integrated with database management systems (DBMS).Optics theory is discussed and applied to specific target, graphical renderization of pre-determined geometric micro-structured coatings are implemented and the fundamental outputs to evaluate the real status of the surface are described and treated to be a reliable knowledge database. Overcomming the experimental requirements to build a reliable theoretical base to implement consistent outputs to the proposed technique, this dissertation brings the analysis criteria identified to be applied in further studies, the investigation and application of well-known theoretical founding to be a starting to new techonolgies contributing to open new perspectives on this field, joining the necessary interdisciplinarity on computer science, physics and engineering to improve the knowledge on the field of quality assurance, applied, in this particular case, on aerospace industry.