48
06
Korea Aerospace Research Institute Promising Technologies for Commercialization
Outline of Technology
TLO of the KARI
Person-in-charge
Senior Administrator Moon-Hee, Cho
E-mail : moonyxp@kari.re.kr
R&D Performance Diffusion Division
Composite
material
Z-pinning
Technology of inserting pins in a thickness
direction of a composite material laminated
structure to prevent interlayer separation or
strengthening a connection part by driving pins
into a joint part when a plurality of composite
material members are formed integrally.
Inventor
Principal Researcher Choi, Ik-Hyeon
Team
Material Structure Research Team
Status of right
• US : 9434110
• US /JP/CN : 8205654 / 2010-522655 / 101668633
Title
• METHOD OF MANUFACTURING UNEVENNESS
SHAPED Z-PIN AND Z-PIN MANUFACTURED USING
THE SAME AND COMPOSITE STRUCTURE INCLUD-
ING THE Z-PIN
• COMPOSITE LAMINATED STRUCTURE REIN-
FORCED By INSERTING PINS, A METHOD AND A AP-
PARATUS FOR MAKING THE SAME AND A METHOD
FOR MAKING THE APPARATUS
Technical features and
advantages
Distinctiveness
• It does not cause any waste of materials, and a
pre- and post-process of removing compressed
foam before and after molding, and projecting
pins is not necessary.
49
Production of confirmed parts/system and prototype
Technical Readiness Level
TRL 1
TRL 2
TRL 3
TRL 5
TRL 6
TRL 7
TRL 8
TRL 9
TRL 4
Technical effects
• Since little influence is given to a
process of manufacturing current
composite materials, immediately
applicable in industrial fields.
• Upon comparison with drilling work
and use of metal fasteners, insertion
of an automated Z-pin can achieve a
70% reduction on manufacturing costs.
Technical features and advantages
Technical detail
This technology is in a state in which a sample product has been manufactured,
and has been applied to manufacturing of small vessels in Korea.
Tension Fatigue Test Results for Joint Part
• Static tensile test results for unevenness shaped pin single-lap shear joint
- Pin having a diameter of 0.5 mm, made of stainless steel, and having a pin density of 2.2% (an
interval of 3 mm) and 4.9% (an interval of 2 mm).
- According to the joint part having a thickness of 6 to 8 mm, static strength is increased by 54 to 69%.
• Tensile test results for unevenness shaped pin single-lap shear joint part
- Pin having a diameter of 0.5 mm, made of stainless steel, and having a pin density of 2.2% (an
interval of 3 mm) and 4.9% (an interval of 2 mm).
- Fatigue strength is improved by about 100%, and fatigue life is improved by 100 times.
50
06
Market and future prospects
Composite
material
Z-pinning
• AZTEX applied this technology to connect the engine bay
door to the air inlet duct of a rear fuselage for F/A-18 E/F
Super Hornet instead of a titanium fastener, so that the cost
was reduced by $83,000 per aircraft and the weight was
reduced by 17 kg per aircraft.
• Applied to the cargo door of C17 Globemaster and Boeing-
Sikorsky RAH-66 Comanche. X-CorTM that has the
sandwich structure to which the Z-pinning technology is
applied is applied to the tail cone in UH60M Black Hawk,
so that a weight is reduced by 21 kg per helicopter.
• Examples of use for roll over bar of Formula 1 Racing Car
51
Applications
• Carbon fiber/glass fiber composite materials are broadly used for light weight products that
require higher specific stiffness/specific strength than metal such as aerospace/wind turbine blade/
boat/yacht/high speed train/automobile/sporting goods.
• For the purpose of use of metal pins such as stainless steel in Korea and broad use in various
fields of manufacturing composite materials, research into Z-pinning patch/elastic pad concept
has been conducted to be applied to the various fields of manufacturing composite materials.