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Airtech develops Airpad HTX
TECHNOLOGY
Airbus and MIT look to digital manufacturing Under a new research agreement Airbus and the Massachusetts Institute of Technology (MIT) will explore the potential of digital manufacturing in aircraft construction. This could result in composite aerospace structures being assembled much like snap-together building blocks rather than manufactured as large, expensive, one-piece parts. Aircraft manufacturers are increasingly adopting composite materials to reduce aircraft weight and operating costs. Airbus’ latest model, the A350 XWB, is over 50 wt% composite. Current composite airframe manufacture involves the fabrication of large single-piece parts, an expensive process. (The fuselage of the A350 XWB, for example, is made up of a number of large composite panels which are then joined together.) The digital material concepts being developed at MIT could lead to lighter weight structures and lower construction and assembly costs.
Digital material technology is based on the idea that a complex structure can be constructed by assembling a simple set of discrete components. The parts are assembled to give a structure that is lightweight, extremely durable, and easy to disassemble and reassemble. MIT’s ‘cellular composite materials’ technique combines three fields of research. These include: fibre composites; cellular materials (those made with porous cells); and additive manufacturing (such as 3D printing, where structures are built by depositing rather than removing material). Airbus will work with MIT’s Center for Bits and Atoms (CBA), which has been developing new methods for manufacturing structures out of carbon fibre reinforced plastic (CFRP). CBA Director Neil Gershenfeld and his colleague Kenneth C. Cheung recently published a paper in the journalScience on Reversibly Assembled Cellular
Composite Materials. This outlines the assembly of a 3D lattice of mass-produced CFRP parts with integrated mechanical interlocking connections. Cheung produced flat, crossshaped composite pieces that were clipped into a cubic lattice of octahedral cells, a structure called a ‘cuboct.’ The parts form a structure that is 10 times stiffer for a given weight than existing lightweight materials, according to the researchers. The structure can also be disassembled and reassembled easily – such as to repair damage. The repair of the composite aircraft fuselages now entering service is a challenge facing the aerospace industry. The individual composite parts can be mass-produced and MIT is developing a robot to assemble them into wings, aircraft fuselages, and other parts. Other applications such as bridge decks are also possible. The MIT technique allows much less material to carry a given
Airtech develops Airpad HTX Airtech Advanced Materials Group has introduced Airpad HTX, an uncured non-silicone rubber that can be made into caul sheets and flexible mandrels.
Airpad HTX from Airtech Advanced Materials Group.
www.reinforcedplastics.com
Airtech adds that Airpad HTX has been formulated to provide enhanced performance in comparison to other rubber caul sheet materials.
release film, resulting in a longer lasting tooling. Airpad HTX also bonds to itself aggressively, making it easier to repair. Heat aging studies show longer life in high temperature applications and it offers high Shore hardness for better definition. Airpad HTX is resistant to solvents, allowing the tool to be more durable and can be released using standard release agents.
Benefits claimed are that it bonds aggressively to bondable
Airtech Advanced Materials Group; www.airtechonline.com
A sample of the cellular composite material being prepared for strength testing at MIT. (Picture courtesy of Kenneth Cheung.)
load. This could reduce the weight of aircraft and other vehicles, which in turn would lower fuel use and operating costs. The costs of construction and assembly would also be lower. Unlike conventional composite materials, which tend to fail abruptly and at large scale when stressed to the breaking point, the modular system tends to fail incrementally, the researchers say. This makes it more reliable and easier to repair. The possibility of linking a number of parts introduces a new degree of design freedom into composite manufacturing. MIT has shown that by combining different part types, they can make ‘morphing’ structures with identical geometry but that bend in different ways in response to loads. This means that instead of moving only at fixed joints, the wing of an aircraft could change shape. Airbus; www.airbus.com Massachusetts Institute of Technology; web.mit.edu
JANUARY/FEBRUARY 2014
REINFORCEDplastics
13
Airbus and MIT look to digital manufacturing Under a new research agreement Airbus and the Massachusetts Institute of Technology (MIT) will explore the potential of digital manufacturing in aircraft construction. This could result in composite aerospace structures being assembled much like snap-together building blocks rather than manufactured as large, expensive, one-piece parts. Aircraft manufacturers are increasingly adopting composite materials to reduce aircraft weight and operating costs. Airbus’ latest model, the A350 XWB, is over 50 wt% composite. Current composite airframe manufacture involves the fabrication of large single-piece parts, an expensive process. (The fuselage of the A350 XWB, for example, is made up of a number of large composite panels which are then joined together.) The digital material concepts being developed at MIT could lead to lighter weight structures and lower construction and assembly costs.
Digital material technology is based on the idea that a complex structure can be constructed by assembling a simple set of discrete components. The parts are assembled to give a structure that is lightweight, extremely durable, and easy to disassemble and reassemble. MIT’s ‘cellular composite materials’ technique combines three fields of research. These include: fibre composites; cellular materials (those made with porous cells); and additive manufacturing (such as 3D printing, where structures are built by depositing rather than removing material). Airbus will work with MIT’s Center for Bits and Atoms (CBA), which has been developing new methods for manufacturing structures out of carbon fibre reinforced plastic (CFRP). CBA Director Neil Gershenfeld and his colleague Kenneth C. Cheung recently published a paper in the journalScience on Reversibly Assembled Cellular
Composite Materials. This outlines the assembly of a 3D lattice of mass-produced CFRP parts with integrated mechanical interlocking connections. Cheung produced flat, crossshaped composite pieces that were clipped into a cubic lattice of octahedral cells, a structure called a ‘cuboct.’ The parts form a structure that is 10 times stiffer for a given weight than existing lightweight materials, according to the researchers. The structure can also be disassembled and reassembled easily – such as to repair damage. The repair of the composite aircraft fuselages now entering service is a challenge facing the aerospace industry. The individual composite parts can be mass-produced and MIT is developing a robot to assemble them into wings, aircraft fuselages, and other parts. Other applications such as bridge decks are also possible. The MIT technique allows much less material to carry a given
Airtech develops Airpad HTX Airtech Advanced Materials Group has introduced Airpad HTX, an uncured non-silicone rubber that can be made into caul sheets and flexible mandrels.
Airpad HTX from Airtech Advanced Materials Group.
www.reinforcedplastics.com
Airtech adds that Airpad HTX has been formulated to provide enhanced performance in comparison to other rubber caul sheet materials.
release film, resulting in a longer lasting tooling. Airpad HTX also bonds to itself aggressively, making it easier to repair. Heat aging studies show longer life in high temperature applications and it offers high Shore hardness for better definition. Airpad HTX is resistant to solvents, allowing the tool to be more durable and can be released using standard release agents.
Benefits claimed are that it bonds aggressively to bondable
Airtech Advanced Materials Group; www.airtechonline.com
A sample of the cellular composite material being prepared for strength testing at MIT. (Picture courtesy of Kenneth Cheung.)
load. This could reduce the weight of aircraft and other vehicles, which in turn would lower fuel use and operating costs. The costs of construction and assembly would also be lower. Unlike conventional composite materials, which tend to fail abruptly and at large scale when stressed to the breaking point, the modular system tends to fail incrementally, the researchers say. This makes it more reliable and easier to repair. The possibility of linking a number of parts introduces a new degree of design freedom into composite manufacturing. MIT has shown that by combining different part types, they can make ‘morphing’ structures with identical geometry but that bend in different ways in response to loads. This means that instead of moving only at fixed joints, the wing of an aircraft could change shape. Airbus; www.airbus.com Massachusetts Institute of Technology; web.mit.edu
JANUARY/FEBRUARY 2014
REINFORCEDplastics
13