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ITEMB: Integrated Full Composite Main Landing Gear Bay Concept

Periodic Reporting for period 2 - ITEMB (ITEMB: Integrated Full Composite Main Landing Gear Bay Concept)

Reporting period: 2018-03-01 to 2018-08-31

"The overall objective of ITEMB is to propose a new generation of Main Landing Gear Bay in the scenario of a Body Landing Gear with the intent of reach the best Design to Cost.
The challenging targets, compared to present Single Aisle Aircraft solution, of weight saving (5-10%), cost saving (5%), high production rate (60 A/C per month) and Project maturity at Level of TRL3, have been faced successfully by the ITEMB Consortium made by: PROTOM as Engineering and leader, LAER for Manufacturing and University of Naples for readiness assessments and testing.
This scenario means: more economic competitiveness for European Industry in manufacturing aeronautical structure, reduced fleet maintenance cost and contribution to fuel saving.

The two main components of the Maing Landing Gear Bay are the Horizontal ""Roof"" (about 2,7m large x 2,4m long) and the Rear Pressure Bulkhead (about 1,5m deep x 2,7m wide). A “bag against bag” technology with the target of Monolithic, One Shot Cured Structure as much as possible to reduce parts, assembly and manufacturing flow, has been adopted and the capability to get a good product for a Landing Gear Bay has been achieved.

At the end of the Project, the all Composite Structure (Horizontal and Vertical Bulkheads) Weight saving is predicted to be about 21% and saving on assembly time up to 95% (using an “hole to hole assembly approach, mainly due to the huge reduction of fastening, compared to a similar structure A350 style.

In the second reporting period design and process steps have been further analyzed and optimized to more reduce weight and cost and produce a representative large technology demo together with more details demo. So layups have been designed, tooling and process steps detailed, template for assembly cost agreed with Airbus and TRL3 assessed on the basis of Airbus check list. Benefits of the ITEMB approach are secured by a managed risk level and manufacturing trials and testing coupons have been the main risk mitigation actions.
A plus of the project is the applicability of the resulting design/process to other families of structural items (i.d movable surfaces) and also in presence of architectural change of the Landing Gear or Fuselage.

In conclusion ITEMB Consortium is now in possess of the technology that could be easily scaled to future MLG application.

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An intense and comprehensive work has been performed during the reporting period.
The innovation has been mainly in the process and design aiming to demonstrate that a one-piece design approach without using special and expensive materials and achievable in a short time for real manufacturing, would be feasible avoiding the cost of assembling many parts.
To pursue this result an integrated work between manufacturing and engineering has been done. A “bag against bag” technology has been adopted and the capability to get a good product for a Landing Gear Bay has been achieved, supported by:
• Manufacturing trials followed by inspections and corrective actions and manufacturing flow definition all included in dedicated technical documentation. This experience has been the basis for an effective cost analysis of the product.
• Tooling and methods of Fabrication and Assembly analysis (detailed in the relevant Deliverables); the proposed “Hole to Hole “ assembly supported by tests to verify the statistical analysis data.
• Production Line design balancing equipments and estimating takt time.
• Cost analysis using for Assembly cost (Airbus priority) templates shared with Airbus.
• Laboratory tests for the critical detail being the intersection (node) of longerons to the panel. This testing campaign has been successful showing that no showstopper exists in the Design/Process.
• Investigation on automation for panels layup, curved filler and NDI
• Engineering design and stress analysis at global and detail level and including a huge FEM simulation (starting from the Center Section global FEM supplied by Airbus, and associating local fine mesh models) to demonstrate that a structure without ribs and “flexible” can sustain loads and be stable up to UL reaching an optimum balance of strength and flexibility to reduce impact of deflections imposed by the wing. 3D CAD models are now available including layups and main joints analysis.
TRL3 achievement has been based on Airbus check list.
Two alternatives have been compared and a preferred configuration selected with the concurrence of Airbus Leadership.
Optimization of design and process to reduce weight and cost and produce a representative technology demo has been performed during Second Period of ITEMB operations. A special attention has been given to the assembly process in order to reduce/nullify shims and speed the assembly of the Bay to the Fuselage in view of the target high rate.
Manufacturing trials and testing coupons have been the main risk mitigation actions. The Consortium has activated even more Risk mitigation actions than planned in the Annex1 because required by the novelty of the design/process.
Main results can be summarized as follows:
At the end of the Project, the all Composite Structure (Horizontal and Vertical Bulkheads) weight saving is predicted to be about 21% and saving on assembly time up to 95% (using an “hole to hole assembly approach), mainly due to the huge reduction of fastening, compared to a similar structure A350 style.
In conclusion ITEMB Consortium is now in possess of a new technology that could be easily scaled to future MLG application and other Aircraft Components.
Dissemination has produced:
• thesis at University of Naples: on FEM simulation of the RPB, on testing campaign data collection and analysis, on different technologies of data acquisition and on potential usage of Additive Manufacturing Technique (FDM) for the final demo tooling.
• training on basic ITEMB design principles for bachelor and master degree students
• participation to Social Events like Conference and Exibition: the 2018 EASN Conference is an example
In detail the estimated number of persons reached by communication and dissemination activities are:
• Scientific community: 450
• Industry: 9
• Civil society: 1
• General Public: 900
• Media: 200
• Investors: 7
• Customers: 6
State of art of participants (AIRBUS and ITEMB Consortium) has made an important progress achieving a technology that was not in their background. The technology, in the actual case suited to a MLGB, may have important impacts on CFRP components manufacturing because:
• the monolithic approach offers the opportunity of an optimum usage of Composite reducing parts, assembly time and manufacturing flow
• the process may be adapted to other type of components and aircraft category
ITEMB has achieved even better results than objective and the production of a large demo strengthens the the effective possess of the technology.
The achievement of the technology may have a positive impact on all participants because strengthen their position in the market and can also have an implication on Italian participants having a positive impact on south area of Italy: from this point of view the most optimistic scenario is a continuation of cooperation in next AIRBUS products.
As first deployment same ITEMB team together with other players is applying the design principle to the Wing of a new UAV for civil application.
An overall view of the Main Landing Gear Bay as designe by ITEMB
Testing set-up, failure and capability shown
Manufacturing Trials
Overall view of coarse FEM for strenght and stability verification according to AI requirements