Modular Joints for Composite Aircraft Components (MOJO)

Problem:

Structural bonding can offer considerable cost savings over riveting as an assembly technique, but is not a widely accepted alternative.

 Approach:

Cost savings can achieved with out-of autoclave infusion processes and tailored preforms made of high performance textiles. Adhesive bonding also provides significant cost and weight savings. The challenge is to create synergy between preform infusion and adhesive bonding processes and demonstrate the capability.  To resolve this challenge, the MOJO project, a collaboration between 12 international partners including CRC-ACS, was set up under the European Union's Sixth Framework Project.

Solution:

The innovations combined tailored preformed profiles for modular joints with structural bonding processes, including out-of-plane reinforcements. The main components of this closed beam were manufactured with out-of autoclave infusion processes such as Resin Transfer Moulding (RTM) and Vacuum Assisted Resin Infusion (VARI). Non-crimp carbon fabrics and tailored preformed profiles made of high-performance textiles were used. Adhesive processes with both film and paste adhesive were developed and successfully employed for the assembly.

In particular, six of the ten modular joints in the demonstrator were successively bonded using the Insertion Squeeze Flow (ISF) bonding technology to which ACS Australia staff were major contributors.

Outcome:

The MOJO demonstrator was one of the very first representative aeronautical structures designed for assembly by structural adhesive bonding, which provides damage tolerance characteristics. MOJO makes a construction set available with cost and weight saving potentials of at least 20 % and 15 %, respectively. Applications will include stiffened wing-skin panels, vertical and horizontal tail planes, flap-track beams, cargo and passenger doors, cargo- and passenger-door surroundings, as well as unmanned air vehicles. Demonstration projects like MOJO will help change minds and gain wider acceptance of “rivettless” structures.

The MOJO project received the 2010 JEC Innovation Award in the category of Process.

ACS Australia was established in 2008 by the Cooperative Research Centre for Advanced Composite Structures (CRC-ACS) for commercialisation of the expertise and technologies developed by CRC-ACS. All ACS Australia staff also work within CRC-ACS.