Sutar Sunil, Ganpule Shailesh
Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India.
J Biomech Eng. 2022 May 1;144(5). doi: 10.1115/1.4053059.
Blast-induced traumatic brain injury (bTBI) research is crucial in asymmetric warfare. The finite element analysis is an attractive option to simulate the blast wave interaction with the head. The popular blast simulation methods are ConWep-based pure Lagrangian, Arbitrary-Lagrangian-Eulerian, and coupling method. This study examines the accuracy and efficiency of ConWep and coupling methods in predicting the biomechanical response of the head. The simplified cylindrical, spherical surrogates and biofidelic human head models are subjected to field-relevant blast loads using these methods. The reflected overpressures at the surface and pressures inside the brain from the head models are qualitatively and quantitatively evaluated against the available experiments. Both methods capture the overall trends of experiments. Our results suggest that the accuracy of the ConWep method is mainly governed by the radius of curvature of the surrogate head. For the relatively smaller radius of curvature, such as cylindrical or spherical head surrogate, ConWep does not accurately capture decay of reflected blast overpressures and brain pressures. For the larger radius of curvature, such as the biofidelic human head, the predictions from ConWep match reasonably well with the experiment. For all the head surrogates considered, the reflected overpressure-time histories predicted by the coupling method match reasonably well with the experiment. Coupling method uniquely captures the shadowing and union of shock waves governed by the geometry-driven flow dynamics around the head. Overall, these findings will assist the bTBI modeling community to judiciously select an objective-driven modeling methodology.
爆炸所致创伤性脑损伤（bTBI）研究在非对称战争中至关重要。有限元分析是模拟爆炸波与头部相互作用的一个有吸引力的选择。常用的爆炸模拟方法有基于ConWep的纯拉格朗日法、任意拉格朗日-欧拉法和耦合方法。本研究考察了ConWep方法和耦合方法在预测头部生物力学响应方面的准确性和效率。使用这些方法，将简化的圆柱形、球形替代模型和生物逼真的人体头部模型置于与实际战场相关的爆炸载荷下。针对现有实验，对头部模型表面的反射超压和脑内压力进行了定性和定量评估。两种方法都捕捉到了实验的总体趋势。我们的结果表明，ConWep方法的准确性主要取决于替代头部的曲率半径。对于曲率半径相对较小的情况，如圆柱形或球形头部替代模型，ConWep不能准确捕捉反射爆炸超压和脑内压力的衰减。对于曲率半径较大的情况，如生物逼真的人体头部，ConWep的预测与实验结果相当吻合。对于所有考虑的头部替代模型，耦合方法预测的反射超压-时间历程与实验结果相当吻合。耦合方法独特地捕捉了由头部周围几何驱动的流动动力学所支配的冲击波的阴影和合并。总体而言，这些发现将有助于bTBI建模群体明智地选择一种以目标为导向的建模方法。
