Department of Biomedical Engineering, Wayne State University, 818 W Hancock Avenue, Detroit, MI 48201.
Biocore, LLC, 1627 Quail Run, Charlottesville, VA 22911.
J Biomech Eng. 2021 Jun 1;143(6). doi: 10.1115/1.4050025.
Though energy attenuating (EA) seats for air and spacecraft applications have existed for decades, they have not yet been fully characterized for their energy attenuation capability or resulting effect on occupant protection in vertical underbody blast. EA seats utilize stroking mechanisms to absorb energy and reduce the vertical forces imparted on the occupant's pelvis and lower spine. Using dynamic rigid-body modeling, a virtual tool to determine optimal force and deflection limits was developed to reduce pelvis and lower spine injuries in underbody blast events using a generic seat model. The tool consists of a mathematical dynamic model (MADYMO)-modified human body model (HBM), basic EA seat model, and an optimizing sequence using modefrontier software. This optimizing tool may be shared with EA seat manufacturers and applied to military seat development efforts for EA mechanisms for a given occupant and designated blast severity. To optimally tune the EA seat response, the MADYMO human body model was first updated to improve its fidelity in kinematic response data for high rate vertical accelerative loading relative to experimental data from laboratory simulated underbody blast tests using postmortem human surrogates (PMHS). Subsequently, using available injury criteria for underbody blast, the optimization tool demonstrated the ability to identify successful EA mechanism critical design value configurations to reduce forces and accelerations in the pelvis and lower spine HBM to presumed noninjurious levels. This tool could be tailored by varying input pulses, force and deflection limits, and occupant size to evaluate EA mechanism designs.
尽管用于空气和航天应用的能量衰减（EA）座椅已经存在了几十年，但它们的能量衰减能力或在垂直底盘爆炸中对乘员保护的影响尚未得到充分表征。EA 座椅利用冲程机制来吸收能量并降低施加在乘员骨盆和下脊柱上的垂直力。使用动态刚体建模，开发了一种虚拟工具来确定最佳力和挠度限制，以使用通用座椅模型减少底盘爆炸事件中骨盆和下脊柱受伤的风险。该工具包括一个数学动态模型（MADYMO）修改后的人体模型（HBM）、基本的 EA 座椅模型和使用模式前沿软件的优化序列。该优化工具可与 EA 座椅制造商共享，并应用于给定乘员和指定爆炸严重程度的军用座椅 EA 机制的开发工作。为了优化 EA 座椅的响应，首先更新了 MADYMO 人体模型，以提高其在相对于使用死后人体替代品（PMHS）进行的实验室模拟底盘爆炸测试的实验数据的高速率垂直加速加载下的运动学响应数据的逼真度。随后，使用底盘爆炸的可用损伤标准，该优化工具展示了识别成功的 EA 机制关键设计值配置的能力，以将骨盆和下脊柱 HBM 中的力和加速度降低到假定的非损伤水平。可以通过改变输入脉冲、力和挠度限制以及乘员尺寸来调整此工具，以评估 EA 机制设计。
