A New Model to Calculate Friction Coefficients and Shear Stresses in Thermal Drilling

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Journal of Manufacturing Science and Engineering

DOI:https://doi.org/10.1115/1.2815341· OSTI ID:930828

Qu, Jun ^[1]; Blau, Peter Julian ^[1]

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1. ORNL

A new analytical model for thermal drilling (also known as friction drilling) has been developed. The model distinguishes itself from recent work of other investigators by improving on two aspects: (1) the new model defines material plastic flow in terms of the yield in shear rather than the yield in compression, and (2) it uses a single, variable friction coefficient instead of assuming two unrelated friction coefficients in fixed values. The time dependence of the shear stress and friction coefficient at the hole walls, which cannot be measured directly in thermal drilling, can be calculated using this model from experimentally-measured values of the instantaneous thrust force and torque. Good matches between the calculated shear strengths and the handbook values for thermally drilling low carbon steel confirm the model's validity.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: EE USDOE - Office of Energy Efficiency and Renewable Energy (EE)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 930828
• Journal Information: Journal of Manufacturing Science and Engineering, Journal Name: Journal of Manufacturing Science and Engineering Journal Issue: 1 Vol. 130
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON STEELS
COMPRESSION
DRILLING
FRICTION
PLASTICS
SHEAR
SHEAR PROPERTIES
STRESSES
TIME DEPENDENCE
TORQUE