Energy Considerations If we take PDA measurements….
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Transcript of Energy Considerations If we take PDA measurements….
Energy ConsiderationsIf we take PDA measurements….
Energy Concepts
• Potential Energy• Rated Energy• Kinetic Energy (Hammer Efficiency)• Transferred Energy (ENTHRU)
…we can calculate the Transferred Energy
WR
h
ER = WR hManufacturer’s Rating
WR
Max ET = ∫F(t) v(t) dt(ENTHRU)
ηT = ENTHRU/ ER (transfer ratio or efficiency)
Measure Force, F(t)Velocity, v(t)
Statistical Summaries Transferred energy ratios at End of Driving
Statistical Summaries Transferred energy ratios at End of Driving
Statistical Summaries Transferred energy ratios at End of Driving
Statistical Summaries Transferred energy ratios at End of Driving
Energy
• Three types of energy:• Potential or rated energy (mgh)
• Friction inside hammer• Inclination
• Kinetic or impact energy (mv2/2)• Hammer cushion• Helmet • Pile cushion
• Transferred energy or ENTHRU (PDA)• Pile length• Resistance