Theoretical and experimental investigations on the spinning BTA deep-hole drill shafts containing fluids and subject to axial forces

The object of this investigation is to develop equations of motion and analyze the eigenproperties of spinning boring trepanning association (BTA) deep-hole drill shafts containing flowing fluid and subject to compressive axial force. The energy formulations are based on a coordinate system attached to the spinning shaft (floating coordinate system), and the equations of motion were derived using Hamilton’s principle. This problem was studied for two different models: a Timoshenko beam model (which includes shear deformation, rotatory inertia moment, and gyroscopic moment effects) and a Euler–Bernoulli beam model. Galerkin’s method was used to obtain solutions of the dynamic system. And two kinds of experimental test were performed to investigate the eigenproperties of spinning BTA deep-hole drill shafts: impulsive testing for non-spinning tool shafts, and random-input excitation testing for spinning tool shafts. Experimental results are also compared with simulation results.