Abstract: Longitudinal and torsional vibrations in a drill string consisting of drill pipe and collars, and the boundary conditions at the ends of the string, are discussed. A trial-and-error method of ...

Abstract: This paper describes equipment which has been developed for the measurement of axial force, torque, and axial and rotational motions at the top of a drill string. Measurements made in two ...

Abstract: Relationships between microstructural and mechanical aging effects in eutectic PbSn and Pb-free solder alloy Sn3.9Ag0.6Cu are reported and compared. The room temperature aged Sn3.9Ag0.6Cu alloy ...

Abstract: An iterative procedure is presented for the balancing of a flexible rotor. In addition to determining optimal correction weights, the number and axial positions of the balance planes are ...