Vibration contral of beams and arch members by member-type dynamic vibration absorbers with connecting dampers : 1st report, tuning method of dynamic absorbing members

In this paper, new member-type dynamic vibration absorbers are presented for controlling the several predominant modes of a beam and an arch member (main members) under harmonic excitation due to periodic load and joint motion, which consist of a beam and an arch member (dynamic absorbing members) under the same boundary condition as those of the main members and with connecting dampers between the main and dynamic absorbing members. Equations of motion of the system in modal coordinates of the main members become equal to those of the two-degrees-of-freedom system with two masses, two springs and a damper when the dampers distributed uniformly along the axis of the member and the concentrated dampers arranged with close separation along the member are used as the connecting dampers. Formulas and procedure for optimum design of the member-type dynamic vibration absorbers are presented using the optimum tuning method of a dynamic absorber in two-degrees-of freedom system mentioned above.