Periodic Reporting for period 2 - TOD (Thermoplastic on Doors)
Okres sprawozdawczy: 2020-02-01 do 2022-01-31
The use of composite materials in aeronautics has brought a step change to the way aircraft are designed and built, mainly with a drive for light-weighting. However, the use of thermoplastic composites, until now has come at a price in terms of manufacturing recurring and non-recurring costs, as well as long lead times and relatively modest production output. Notwithstanding these issues, the use of thermoplastics offers considerable advantages over the more established thermosets. These include avoiding the need for long curing cycles at high temperature and pressure (in autoclaves), and utilising the ability of the thermoplastic to be reheated, which opens the door to alternative manufacturing processes such as induction welding. Thermoplastics also have the benefit that at end of life they can be recycled to produce new polymer materials for other applications.
In order to progress this technology, the Clean Sky 2 programme is developing a large-scale regional aircraft fuselage demonstrator. The TOD project is contributing to this programme by producing a full-scale thermoplastic door, together with its surround and fittings, manufactured using a number of advanced techniques.
The specific objectives of the project were:
• Advance the industrial know-how on the above mentioned thermoplastic technologies
• Develop fast, efficient and reliable automated manufacturing processes
• Assess the weight reduction provided by thermoplastic technologies
• Develop optimum manufacturing solutions (additive manufacturing, Linear friction welding, machining) for manufacture of metallic components in the door locking mechanism
• Build an integrated and complete new Tier 1 supply chain
• Reduce impact cost of Non Recurrent Activities
• Decrease the environmental footprint
The project has been successful in demonstrating that an aircraft door can be manufactured by use of thermoplastic material, supported by a number of innovative techniques for metallic parts still required. This can potentially reduce the environmental footprint of the manufacture by up to 30%
The main gain achieved is the reduced cost for assembling thanks to a semi-automated welding process that can avoid the manual operations of drilling and mechanical fasteners installation.
The second gain is the reduction in waste material using parts produced by Additive Manufacturing techniques, since there is no removed and scrapped material from the original raw material block as produced by mechanical milling (fly-to-buy ratio is near 5% for the latter technique)
The final gain for thermoplastic material use is the reduced cost for manufacturing (no autoclave process) and the weight reduction compared to a conventional aluminium door that is estimated approximately equal to -48% (the main gain is on external skin and intercostals).
There is some additional cost for the thermoplastic door compared to a conventional aluminium door. The cost for production of a single composite door is €90k compared to €48k for the aluminium. However, with an assumed learning curve slope of 87%, the cost of the thermoplastic door reduces to €64k by the production of the 40th door.
In order to progress this technology, the Clean Sky 2 programme is developing a large-scale regional aircraft fuselage demonstrator. The TOD project is contributing to this programme by producing a full-scale thermoplastic door, together with its surround and fittings, manufactured using a number of advanced techniques.
The specific objectives of the project were:
• Advance the industrial know-how on the above mentioned thermoplastic technologies
• Develop fast, efficient and reliable automated manufacturing processes
• Assess the weight reduction provided by thermoplastic technologies
• Develop optimum manufacturing solutions (additive manufacturing, Linear friction welding, machining) for manufacture of metallic components in the door locking mechanism
• Build an integrated and complete new Tier 1 supply chain
• Reduce impact cost of Non Recurrent Activities
• Decrease the environmental footprint
The project has been successful in demonstrating that an aircraft door can be manufactured by use of thermoplastic material, supported by a number of innovative techniques for metallic parts still required. This can potentially reduce the environmental footprint of the manufacture by up to 30%
The main gain achieved is the reduced cost for assembling thanks to a semi-automated welding process that can avoid the manual operations of drilling and mechanical fasteners installation.
The second gain is the reduction in waste material using parts produced by Additive Manufacturing techniques, since there is no removed and scrapped material from the original raw material block as produced by mechanical milling (fly-to-buy ratio is near 5% for the latter technique)
The final gain for thermoplastic material use is the reduced cost for manufacturing (no autoclave process) and the weight reduction compared to a conventional aluminium door that is estimated approximately equal to -48% (the main gain is on external skin and intercostals).
There is some additional cost for the thermoplastic door compared to a conventional aluminium door. The cost for production of a single composite door is €90k compared to €48k for the aluminium. However, with an assumed learning curve slope of 87%, the cost of the thermoplastic door reduces to €64k by the production of the 40th door.
In the First Period of the project, the selection of the material and of the manufacturing process suitable for the door, taking into account the final door geometry as defined by the Topic Manager, was undertaken. The next achievement was to set up the induction welding process for the selected materials and to carry out an extensive analysis of the CAD models that were provided by the Topic Manager, to achieve improvements of the design that will ensure a rapid manufacturing process. The planning for the additive manufacturing of the metallic parts was also undertaken and the relevant methods to be used were fully defined. A dedicated plan for the non-destructive inspection of the parts produced was generated in discussion with the Topic Manager. The relevant information to perform the industrial cost evaluation was provided by DEMA.
In the Second Period, the focus has been fully on taking the designs, specifications and procedures that were developed in the first, and using these to produce all of the components necessary for the assembly of a full-scale thermoplastic composite door, including its surround and sub-structure, for a regional aircraft fuselage barrel. This system comprised 1,312 parts, which were manufactured by a combination of advanced manufacturing techniques; thermoforming, induction welding, linear friction welding and laser powder bed additive. An extensive industrial cost evaluation was also carried out, to ensure that the requirements for scale-up to an economically viable production system were fully understood.
In the Second Period, the focus has been fully on taking the designs, specifications and procedures that were developed in the first, and using these to produce all of the components necessary for the assembly of a full-scale thermoplastic composite door, including its surround and sub-structure, for a regional aircraft fuselage barrel. This system comprised 1,312 parts, which were manufactured by a combination of advanced manufacturing techniques; thermoforming, induction welding, linear friction welding and laser powder bed additive. An extensive industrial cost evaluation was also carried out, to ensure that the requirements for scale-up to an economically viable production system were fully understood.
Thermoforming process (DEMA)
The project has optimised process parameters and equipment necessary to ensure the thermoforming process is capable as a significant rate production technology, to be employed in manufacturing of the primary structure of Commercial Aircraft, by implementing low cost production technology
Induction welding of stringers (CETMA)
The continuous induction welding process has been developed to offer an option for achieving high quality joints in thermoplastic materials, combined with significant weight reduction due to elimination of mechanical fastenings. Within this project the feasibility of manufacturing a large component such as a door, using induction welding for the joints between skin and intercostals, has been demonstrated for the first time.
Metallic door and surround components manufactured by a combination of Linear Friction Welding and Laser Powder Bed Technologies (TWI)
This novel part manufacturing process combination facilitates the rapid manufacture of large, aerospace grade parts from small diameter, shallow powder bed machines. This is an economically attractive alternative to the much larger machines which would be required to build these components using only the laser additive process. This approach has high potential for application in both the Aero and Defence sectors.
Summary
The three optimized methods described above that have been used in the project have the potential to lead to rapid manufacturability, and will have a broader impact in improving both the economics of manufacture and reducing its environmental footprint.
The project has optimised process parameters and equipment necessary to ensure the thermoforming process is capable as a significant rate production technology, to be employed in manufacturing of the primary structure of Commercial Aircraft, by implementing low cost production technology
Induction welding of stringers (CETMA)
The continuous induction welding process has been developed to offer an option for achieving high quality joints in thermoplastic materials, combined with significant weight reduction due to elimination of mechanical fastenings. Within this project the feasibility of manufacturing a large component such as a door, using induction welding for the joints between skin and intercostals, has been demonstrated for the first time.
Metallic door and surround components manufactured by a combination of Linear Friction Welding and Laser Powder Bed Technologies (TWI)
This novel part manufacturing process combination facilitates the rapid manufacture of large, aerospace grade parts from small diameter, shallow powder bed machines. This is an economically attractive alternative to the much larger machines which would be required to build these components using only the laser additive process. This approach has high potential for application in both the Aero and Defence sectors.
Summary
The three optimized methods described above that have been used in the project have the potential to lead to rapid manufacturability, and will have a broader impact in improving both the economics of manufacture and reducing its environmental footprint.