Abstract We studied the apparent mass during vertical whole-body vibration in the frequency range 2–100 Hz at four magnitudes (sinusoidal sweep signals, 1.0, 1.5, 2.0 and 2.5 ms−2 r.m.s.) in 12 males and 12 females with upright and relaxed sitting postures. The first two peaks of apparent mass decreased with increasing vibration magnitude with both postures. The non-linearity characteristics became obscured at the two largest magnitudes and were less transparent with relaxed sitting posture. The peak frequencies and the normalised apparent masses were similar between males and females with both postures. The standardised three degrees-of-freedom parametric model with modified parameters was proposed to predict well the apparent mass of seated human body during vertical vibration in the frequency range 2–100 Hz and in the magnitude range 1.0–2.5 ms−2 r.m.s. Practitioner summary: This study shows the frequency-dependence and magnitude-dependence of biodynamic responses in the frequency range of 2–100 Hz. The magnitude of apparent mass at frequencies above 20 Hz may not be negligible. The proposed 3 DOF model with modified parameters would help with understanding and developing the human-seat system. Abbreviations: WBV: whole-body vibration; DOF: degrees-of-freedom; CMIFs: complex mode indicator functions

中文翻译：

---

在 2-100 Hz 频率范围内的垂直振动期间，就座人体的表观质量

摘要 我们研究了 12 名男性和 12 名女性在 2-100 Hz 频率范围内 4 个量级（正弦扫描信号，1.0、1.5、2.0 和 2.5 ms-2 rms）的垂直全身振动过程中的表观质量。坐姿。表观质量的前两个峰值随着两种姿势的振动幅度的增加而减小。非线性特征在两个最大的幅度处变得模糊，并且在放松的坐姿下不太透明。两种姿势的男性和女性的峰值频率和归一化表观质量相似。提出了具有修改参数的标准化三自由度参数模型，以在 2-100 Hz 频率范围和 1.0-2 幅度范围内的垂直振动期间很好地预测就座人体的表观质量。5 ms−2 rms 从业者总结：本研究显示了 2–100 Hz 频率范围内生物动力响应的频率依赖性和幅度依赖性。频率高于 20 Hz 时的表观质量大小可能不可忽略。提出的具有修改参数的 3 DOF 模型将有助于理解和开发人类座椅系统。缩写：WBV：全身振动；DOF：自由度；CMIF：复杂模式指示函数 全身振动；DOF：自由度；CMIF：复杂模式指示函数 全身振动；DOF：自由度；CMIF：复杂模式指示函数