critical torsional vibration危険ねじり振動[機械]torsional vibration: ねじり振動{しんどう}hull torsional vibration: hull torsional vibration船体ねじり振動[機械]〈97F0012:造船用語―船こく構造〉torsional vibration analysis: ねじり振動解析{しんどう かいせき}