The Optimfloor concept is a composite floor structure designed to replace metallic seat tracks by composite stiffeners that are directly integrated into the floor panels. Unlike current aircraft floor panels, Optimfloor says their floor panel is an integral part of the aircraft structure and contributes to the overall stiffness.
The Optimfloor concept is able to support seats as well as galleys, lavatories and most types of furniture utilized in current aircraft. The concept is also applicable to other types of transportation such as trains and hyperloops.
Optimfloor says their solution offers several key benefits. First, it offers 20% weight reduction per square meter of the total floor weight in standard fuselage area of current aircraft. The weight of the stiffener is reduced, as a result of the use of composite materials, which offer unique mechanical performance to weight ratios. In addition, Optimfloor decreases the number of fasteners and nutplates that are needed to attach the seat tracks to the floor panels.
Optimfloor panels are homogeneous, bigger than current floor panels and seat-track pre-integrated, therefore the company says they provide easier installation and maintenance by reducing the time spent by operators to install the floor structure.
Additionally, Optimfloor is not subject to corrosion while current seat tracks, which are made from extruded/machined metal alloys, face severe corrosion in aircraft wet areas. In conjunction with those benefits, the company says they designed a quick installation system called Easyfix in order to efficiently attach seats and furniture on the Optimfloor concept. Easyfix is a quick fastener that is easy to install (only one hand is needed to lock it) and it can be fixed in an eighth of a rotation which makes it simple and very fast. It is also a blind fixation that can be installed from only one side.
To meet challenging cost and volume targets, the company chose to use pultrusion to manufacture the seat track. For instance, hundreds of meters of seat tracks are produced for every Airbus A350, and the Airbus A320 program needs more than 60 kilometer a year. Replacing current metallic seat tracks by a competitive composite stiffener can be quite difficult without the use of a continuous high rate and relatively low cost process like pultrusion.
“We were very pleased to work with our partner, Epsilon Composite, who is at the forefront of pultrusion and pull winding manufacturing processes,” Optimfloor says. Designing and manufacturing the composite stiffener was the result of a long, enriching, back-and-forth process between SOGECLAIR Aerospace for the design/stress part and Epsilon Composite for the manufacturing part.
The stacking sequence of the stiffener was first optimized to sustain the maximum loads in the cabin area. The process led to rather a complex stacking that combines low cost carbon fiber tows with special fabrics designed for pultrusion and other mechanical and chemical specifications (Fire, Smoke, and Toxicity) as required in aeronautics.
Mechanical testing was one of the key milestones in the development process. It imformed some useful design choices the company says. Another achievement the company stresses is the damage tolerance of the product. Impact damage is one of the biggest issues of composite materials. The company set a very challenging damage tolerance goal at the very beginning of the project and and says their partner did tremendous work to develop a resin that meets their goal.
The most recent achievement the company accomplished was successfully passing the 16G crash test. This test is required for aircraft seat qualification. Optimfloor says they believe they are the first to complete these tests on composite seat tracks.
Future projects for Optimfloor include an aircraft development program to go further with the solution by taking into account all manufacturer requirements.