Ray W. Herrick Laboratories, School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907-2031, USA.
Ind Health. 2010;48(5):663-74. doi: 10.2486/indhealth.mswbvi-13.
Vehicle occupants are exposed to low frequency vibrations with possible harmful effects such as mild discomfort, lower back pain, and even injury to the spine. Occupational drivers and operators of heavy machinery are exposed to significantly longer duration and higher levels of vibration. Thus, the modeling and prediction of biodynamic response of seated occupants to such vibrations is very important. Since the properties of seating foam affect the response of the occupant, there is need for good models of seat-occupant systems through which the effects of foam properties on the dynamic response can be directly evaluated. A nonlinear planar seat-occupant model which incorporates the nonlinear viscoelastic behavior of seating foam has been developed. This model is used to study response of the occupant to harmonic excitation applied at the seat base, in terms of the frequency response in vertical and fore-and-aft directions, the deflection shapes at resonance, as well as the seat-to-head-transmissibility. In addition, to better understand the role of flexible polyurethane foam in characterizing the system behavior, the response of a single-degree-of-freedom foam-block system is also studied. The effects of different masses riding on the foam block and undergoing vertical vibrations at different acceleration levels are also investigated.
车内人员会暴露在低频振动下，可能会产生轻度不适、下背痛，甚至脊柱受伤等有害影响。职业驾驶员和重型机械操作人员会暴露在更长时间和更高水平的振动下。因此，对座椅乘客对这种振动的生物动力响应进行建模和预测非常重要。由于座椅泡沫的特性会影响乘客的响应，因此需要通过座椅-乘客系统的良好模型来直接评估泡沫特性对动态响应的影响。已经开发了一种包含座椅泡沫的非线性粘弹性行为的非线性平面座椅-乘客模型。该模型用于研究在座椅底座处施加谐波激励时乘客的响应，包括垂直和前后方向的频率响应、共振时的挠度形状以及座椅到头部的传递率。此外，为了更好地了解柔性聚氨酯泡沫在表征系统行为方面的作用，还研究了单自由度泡沫块系统的响应。还研究了不同质量的人骑在泡沫块上并在不同加速度水平下进行垂直振动的效果。
