Role of Friction in the Thermal Development of Ultrasonically Consolidated Continuous Fiber...
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Transcript of Role of Friction in the Thermal Development of Ultrasonically Consolidated Continuous Fiber...
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INTRO TEMPERATURE MEASURMENTPROCESS DESCRIPTION
ROLE OF FRICTION IN THE THERMAL DEVELOPMENT OF ULTRASONICALLY
CONSOLIDATED CONTINUOUS FIBER REINFORCED METAL MATRIX COMPOSITE TAPE
S. Koellhoffer (MSME), S. G. Advani, J. W. Gillespie, T. A. Bogetti (ARL)
University of Delaware . Center for Composite Materials . Department of Mechanical Engineering
THERMAL MODEL RESULTS & CONCLUSIONSMODEL VALIDATION
ACKNOWLEDGEMENTS
This work is supported by the army
research laboratory through the
composite materials research program
Process Components
Sonotrode
Foils/Tapes
Anvil
Bonding Mechanisms
Plastic Deformation
Diffusion
Clamping Force, Fa
Seats knurl pattern
Brings material in contact
Sonotrode Rotation, s
Sonotrode Oscillation, λ Friction
Removes asperities
Oxide dispersal
Heat generation
Plastic deformation
Ultrasonic consolidation has the ability to make
metal matrix composite parts
MMC’s offer exceptionally high stiffness and
strength
Low temperature welding process (10-30% Tmelt)
Underlying science is not well understood
Lack of process maturity
Bonding mechanisms are temperature dependent
Need to quantify thermal development
Infrared Camera Front mounted, 6° angle
Temperature dependent ε
Sampling Rate, 4 Hz Temp across width at nip point
recorded Temperature contours can then
be averaged Vertically – avg T across width
Horizontally – avg T along length
Temperature Variations Across
Tape Width for each IR Image
Friction coefficient determined empirically and validated experimentally Constant μ – μconstant, less accurate, easier to obtain
Variable μ – μRSM, depends on welder parameters
Average Temperature Variation
Across Tape Width
IR FEA-µRSM FEA-µconstant
Ti-6Al-4V Horn
MMC Tape
AA 6061-T6 Substratecwl
fFq
2
Th,
T
T
Fixed T at top and bottom boundaries
Free convection on all edge boundaries
Frictional heat flux applied at slip interface
Temperatures measured across tape width at horn-tape nip point
Temperature Predictions via FE modelConstant µ → 15% Average Error
Empirical, parameter dependent µ
→ 7% Average Error
Trends in parameter dependent µ correlate to trends in literature
Typical Experimental & Simulation Results
horn
IR image overlay
Contour lines in red
3
2
1321
F, λ, # of Cycles
Fri
cti
on
Co
eff
icie
nt
Experim
enta
l M
MC
Tape T
rends
Experim
enta
l
Litera
ture
Tre
nds