Free and forced torsional vibrations Illustrative experiments on a torsion test bar with varying masses; multiple mass oscillator Features - investigation of torsional stiffness and torsional vibrations - behaviour of two-mass and three-mass torsional oscillators Learning objectives/experiments - determine the torsional stiffness of a torsion bar - determine the mass moments of inertia - decay behaviour of torsional vibrations - determine the damping in torsional vibrations - forced torsional vibrations, resonance - torsional vibration systems with multiple masses -- two-mass torsional oscillator -- three-mass torsional oscillator Specification [1] experimental unit for investigating torsional vibrations and torsional stiffness [2] 3 mass disks [3] 4 freely positionable ball-bearing-mounted bearing units with clamping chucks [4] sealed oil damper [5] exciter unit with drive crank; exciter amplitudes 1,4°, 1,8°, 2,4° [6] 4 rotary angle sensors, 0,03V/° [7] electrical exciter control unit for setting and displaying the exciter frequency and for powering the rotary encoder [8] GUNT software for data acquisition via USB under Windows 10 Technical data Torsion bar - 1300mm - Ø 6mm - stainless steel Rigidity: approx. 1,0Nm/rad/m Mass disks - Ø 150mm, approx. 2,7kg - Ø 228mm, approx. 4,8kg Exciter frequency: 1...20Hz Damper coefficient: 0,25...3,5Nm/rad/s 230V, 50Hz, 1 phase 230V, 60Hz, 1 phase; 120V, 60Hz, 1 phase UL/CSA optional LxWxH: 1400x410x400mm Weight: approx. 50kg