Centrifuge modelling of monopiles for offshore wind turbines
DTU Civil Engineering, Technical University of Denmark
Monopile
06/10/2011Ph.D projekt af Rasmus T. Klinkvort 2009-20122
(http://www.ramboll-wind.com/, 2010)(http://www.dongenergy.com ,2010) (Byrne & Houlsby, 2006)
DTU Civil Engineering, Technical University of Denmark
Research method
06/10/2011Ph.D project by Rasmus Klinkvort 2009-20123
Prototype model
Numerical model
Scaled model
Constitutive law
Scaling law
Calibration&
Verification
DTU Civil Engineering, Technical University of Denmark
Research method
06/10/2011Ph.D project by Rasmus Klinkvort 2009-20124
Prototype model
Numerical model
Scaled model
Constitutive law
Scaling law
Calibration&
Verification
DTU Civil Engineering, Technical University of Denmark
Dimensional analysis of a laterally loaded pile in sand
• For a laterally loaded pile
06/10/2011Ph.D project by Rasmus Klinkvort 2009-20125
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503
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50
ϕγ
ππππππππϕγ
dd
dL
de
duf
dH
fFdLeduHfF
DTU Civil Engineering, Technical University of Denmark
Centrifuge modelling
06/10/2011Ph.D project by Rasmus Klinkvort 2009-20126
DTU Civil Engineering, Technical University of Denmark
Centrifuge modelling
06/10/2011Ph.D project by Rasmus Klinkvort 2009-20127
Scale effect – Modelling of models
DTU Civil Engineering, Technical University of Denmark
Scale effect
06/10/2011Ph.D project by Rasmus Klinkvort 2009-20128
DTU Civil Engineering, Technical University of Denmark
Installation effect
06/10/2011Ph.D project by Rasmus Klinkvort 2009-20129
DTU Civil Engineering, Technical University of Denmark
Non-Linear stress distribution
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201210
DTU Civil Engineering, Technical University of Denmark
The non-linear stress distribution effect
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201211
DTU Civil Engineering, Technical University of Denmark
Centrifuge modelling
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201212
Stress level effect
DTU Civil Engineering, Technical University of Denmark
Stress level effect
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201213
DTU Civil Engineering, Technical University of Denmark
Stress level effect
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201214
DTU Civil Engineering, Technical University of Denmark
Modelling technique
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201215
Prototype model
Numerical model
Scaled model
Constitutive model
Scaling laws
Calibration&
Verification
DTU Civil Engineering, Technical University of Denmark
Monotonic tests e=15d, L=6d & d=1-?m
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201216
DTU Civil Engineering, Technical University of Denmark
Monotonic tests e=8.25d, L=6d & d=1-?m
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201217
DTU Civil Engineering, Technical University of Denmark 06/10/2011Ph.D project by Rasmus Klinkvort 2009-201218
DTU Civil Engineering, Technical University of Denmark
Cyclic loading of monopile
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201219
DTU Civil Engineering, Technical University of Denmark
Cyclic loading of monopile ζb=0.35, ζc=-0.5
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201220
DTU Civil Engineering, Technical University of Denmark
Accumulation of deflection – 10 000 cycles
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201221
1000 cycles capture the trend
Fatique limit state 107
cycles
DTU Civil Engineering, Technical University of Denmark
Cyclic p-y curves, e=15d, L=6d & d=1-?m
06/10/2011Ph.D project by Rasmus Klinkvort 2009-201222
06/10/201123 Ph.D project by Rasmus T. Klinkvort 2009-2012
ConclusionsCentrifuge modelling of monopiles: Stress distribution Load eccentricity/Pentration depth... Development of initial subgrade reaction÷ Diameter effect÷ (Size of Stiffness)
Cyclic tests: Accumulation of deflection/rotations Increase in stiffness Damping in the soil÷ Accumulation of porepresure