torsional critical speedねじり臨界速度[電情]critical torsional vibration: critical torsional vibration危険ねじり振動[機械]critical speed: 危険速度｛きけんそくど｝、臨界速度｛りんかい そくど｝critical build-up speed: critical build-up speed臨界立上り速度[電情]
