0-20Hz侧倾振动下坐姿人体生物动力学特性研究

Within 30 Hz, the discomfort caused by a lower-amplitude rotational vibration is as same as that caused by a higher-amplitude vertical vibration. Moreover, a roll vibration can bring more discomfort than a pitch vibration with same magnitudes. As a result, this project focuses on the biodynamics of the seated human body under roll vibration. Experimental studies on human response to roll vibration with multi-seating postures are conducted. According to the vibration modes of the spin, a multi-layer spine physical model is developed and a corresponding human-rigid seat multi-body model in up-right posture is proposed considering the lateral vibration modes of the spine. The effects of the arm-support and the buttock-support conditions on the biodynamic response of the seated human body are studied, and the mechanical models of the arm-arm rest interaction and the buttock-cushion interaction are derived and fitted based on the tested data. Finally, based on above results, a biodynamic model of the arm-supported human body in a flexible seat is developed and validated. Using a car seat as an example, the proposed biodynamic model is applied to predict the human response to the roll vibration and the ride comfort. This project is of significant contribution to explain the subjective evaluation in mechanism point of view and can provide novel method supporting the subjective and objective comfort assessment.

低于30Hz的频率范围内，低幅值的旋转振动可造成与高幅值垂向振动相近的不舒适度，而同幅侧倾振动将比俯仰振动引起更强烈的不舒适感。本项目以人体侧倾振动响应为对象，通过试验与建模方法研究侧倾振动下坐姿人体的生物动力学特性。设计并进行侧倾振动下多坐姿人体振动试验，基于脊椎侧向弯曲振动模态搭建其多层拓扑结构，建立考虑脊椎侧弯的正坐人体-刚性座椅多体模型，研究侧倾振动下人体的振动响应；探索手臂与臀腿支撑对人体侧倾振动响应的影响规律，建立小臂-扶手和臀腿-坐垫接触界面力学模型，定量研究支撑状态改变引起的人体生物动力学特性的变化；最终建立侧倾振动下柔性座椅中手臂支撑人体生物动力学模型并进行试验验证。以汽车座椅为示例，应用所建人体模型进行侧倾振动响应和乘坐舒适性预测。项目研究对从机理上解释主观舒适性评价结果具有重要的科学意义，为从主客观两方面进行乘坐舒适性评价提供新的理论支持和预测方法。

低幅值的旋转振动引发的人体不适与高幅值平动振动相当；旋转振动中，侧倾振动导致的不适较俯仰和横摆振动更为强烈。项目开展了刚性座椅、扶手支撑、坐垫支撑等多边界条件下的正坐人体侧倾振动试验，掌握了人体侧倾动力学特性，探明了支撑对人体响应的影响规律，建立了人体侧倾动力学模型和边界力元，在整车平顺性中进行了理论和模型应用，取得较好效果。. 项目组研制了六自由度振动试验台，进行了多种支撑状态和激励强度下的人体侧倾振动试验，获取了正坐人体侧倾视在惯量和传递率等频响函数，掌握了侧倾激励下的人体动力学特性，发现了人体侧倾运动中1Hz和3Hz表现出的由全身摆动和上肢肌肉横向运动控制的两阶振动模态；探明了“小臂-扶手”、“臀腿-坐垫”支撑条件对人体侧倾响应的影响规律，发现相对高度是扶手支撑作用的主导变量，有效的扶手支撑有助于减小人体主共振幅值，高度不足则会放大人体振动响应，引入坐垫会前移人体共振频率，幅值整体下降；建立了侧倾激励下坐姿人体生物动力学模型，在有/无支撑的坐姿人体侧倾动力学特性上与实验结果吻合良好，具备预测能力；开展了侧倾-侧向激励的等效方法研究，建立了侧倾-侧向激励在人体振动评价中的等效原则，为后续人体多轴振动研究提供了技术路径；将人体模型与整车模型结合，建立了27自由度人-车耦合系统动力学模型，以人体振动响应为目标开展了整车平顺性优化，克服了对地板和座椅导轨振动进行舒适性评价和优化的传统方法的局限，有效地验证了研究结论。. 研究发现的人体侧倾振动模态和传递函数为人体生物动力学建模提供了数据，发现的支撑边界对人体动力学特性的影响规律对人机界面设计提供了依据，建立的侧倾动力学模型和侧倾-侧向等效关系对人体振动评价、预测和优化有实际的指导作用，结合主观评价结果可从机理上解释侧倾振动导致的人体不适成因。