Product Code: ICAL06_P505

Correction of Distortion and Design Shape in Aluminium Structures using Laser Forming
Authors:
Geoff Dearden, The University of Liverpool; Liverpool Great Britain
Stuart Edwardson, The University of Liverpool; Merseyside Great Britain
Emile Abed, The University of Liverpool; Liverpool Great Britain
Ken Watkins, The University of Liverpool; Liverpool Great Britain
Konrad Bartkowiak, Poznan University; Posnan Poland
Presented at ICALEO 2006

The correction of distortion and design shape in manufactured component is increasingly in demand in industry, in particular for aluminium components, where the applications for aluminium and its alloys continue to expand. The need for such correction arises due to factors such as the accumulation of various process tolerances during production, unwanted distortion of the part shape occur during or after processing (e.g. welding), with unpredictable and often irreversible effect, or deviation from design shape resulting from damage during operational service or storage (which may require remedial correction if its usefulness and value are to be maintained). Within this context, a process capable of achieving these actions in an automated, controlled and precise manner would be of significant benefit to industry. Due to these factors a study has been conducted on the use of laser forming (LF) as a method of automated distortion correction.

A system for the controlled 3D LF of continuous surfaces was developed as part of this study. Investigations were carried out into the use of purely geometrical data from a component as a basis for scan strategy development. The error between a measured surface and the desired surface yielded sufficient information for the scan strategy or scan path of the laser to be derived. The magnitude of the error provided a means of varying the process speed and hence the magnitude of forming in a given zone. Employing an iterative pass by pass approach allowed the development of a feedback control system. This iterative error based method was shown to be a significant step towards controlled 3D LF and, as this method relies on the error between a component and a design shape, it was shown to be ideal for the correction of unwanted distortion.