Optimisation of assembly processes for Adhesive bonded Brackets onto the airframe structure
To be published on September 16, 2019 by SAE International in United States
Event: AeroTech Europe
Aircraft manufacturers use adhesive bonded brackets (ABB) to support wire harnesses, looms and sensors. Using ABBs eliminates the necessity to drill holes in the airframe and significantly reduces the assembly time. Such brackets are installed manually on the airframes in numerous locations using high strength epoxy based adhesives. In addition, the application of adhesive onto bracket is carried out manually. Thus it's time consuming and quality relies on operator’s skill sets to apply a certain quantity of adhesive using a predefined pattern, both of which are commonly not controlled. On the other hand, removing the damaged brackets by manual operations tend to cause dents and scratches in metallic airframes and delamination in composites. Prior research indicates that the brackets can be removed by heating them. But, they are not recommendable to aerospace manufacturers due to the longer process times. Therefore, it is vital to find a solution or methods to remove the ABBs without damaging any airframes. The scope of this research encompasses all the areas of design, technology and product development enabling a multi-disciplinary approach. The study aims the optimisation of adhesive bonded bracket operations, by developing an automated adhesive dispensing system to improve the quality and consistency of adhesive application before installation and a prototype for removing the damage brackets using near infrared radiation (NIR). The primary objective is to determine the optimal pattern and adhesive quantity. Optimal parameters will be decided based on the continuous spew of adhesive along the brackets base, the lack of air pockets in the bond after the location of the bracket on the structure and torque testing. The authors will also demonstrate that using NIR, brackets can be removed safely without causing interruptions in a fast paced manufacturing industry.