METHOD OF MODEL ANALYSIS FOR FLEXIBLE HEAD IMPACTING WITH ELASTIC PLANE

摘要/Abstract

摘要： To consider the head is a flexible multi-layer structure and the contact-impact is flexible, the Hertz Contact Law is unsuitable for analyzing the dynamic response of human head impacts elastic plane with initial speed. In this paper, the process of head impacting with elastic plane is modeled as a response of vibrant system, and methods like mechanical network figure and mechanical impedance is taken to resolve this dynamic response problem. Based on the actual head structure, head is modeled as a vibrant model, which concludes the masses of scalp and bone in the impact area, the masses in the other part of the head and the brain, the stiffness of the head, and the damp coefficient of the scalp and brain. At the same time, the elastic plane is simplified as a vibrant model including mass, stiffness and damp. These two vibrant models are linked into one vibrant systematic model. In order to calculate the elastic deformation and the impact acceleration of the head, the models are transformed into mechanical girding figure at violent vibration point. The dynamic impact force of the system, the impact acceleration of the head, the elastic deformation of the plane and the fixed frequency of the system can be worked out by calculating the velocity impedance at the violent vibration point when the initial impact speed is known. The results fit the test data well, which proves that this method is available for the analysis of the dynamic response of the system under impact.

Abstract: To consider the head is a flexible multi-layer structure and the contact-impact is flexible, the Hertz Contact Law is unsuitable for analyzing the dynamic response of human head impacts elastic plane with initial speed. In this paper, the process of head impacting with elastic plane is modeled as a response of vibrant system, and methods like mechanical network figure and mechanical impedance is taken to resolve this dynamic response problem. Based on the actual head structure, head is modeled as a vibrant model, which concludes the masses of scalp and bone in the impact area, the masses in the other part of the head and the brain, the stiffness of the head, and the damp coefficient of the scalp and brain. At the same time, the elastic plane is simplified as a vibrant model including mass, stiffness and damp. These two vibrant models are linked into one vibrant systematic model. In order to calculate the elastic deformation and the impact acceleration of the head, the models are transformed into mechanical girding figure at violent vibration point. The dynamic impact force of the system, the impact acceleration of the head, the elastic deformation of the plane and the fixed frequency of the system can be worked out by calculating the velocity impedance at the violent vibration point when the initial impact speed is known. The results fit the test data well, which proves that this method is available for the analysis of the dynamic response of the system under impact.

中图分类号:

O322

赵桂范;谭惠丰;杜星文. METHOD OF MODEL ANALYSIS FOR FLEXIBLE HEAD IMPACTING WITH ELASTIC PLANE[J]. Applied Mathematics and Mechanics (English Edition), 2003, 24(3): 363-372.

ZHAO Gui-fan;TAN Hui-feng;DU Xing-wen . METHOD OF MODEL ANALYSIS FOR FLEXIBLE HEAD IMPACTING WITH ELASTIC PLANE[J]. Applied Mathematics and Mechanics (English Edition), 2003, 24(3): 363-372.

参考文献

[1] Atsuhiro S, Hirotoshi I, Robert K. Computer simulation of impact test for pedestrian protection [J]. Vehicle Technology, 1998, 52(4):37-42.(in Japanese)
[2] Susan W, Enouen. The development of experimental head impact procedures for simulating pedestrian head injury[J]. SAE Paper, 1988, 88(6):747-765.
[3] Thomas F, Macl A, Johu F W. Pedestrian head impact against the central hood of motor vehiclestest procedure and results[J]. SAE Paper, 1990, 2325(3):1729-1737.
[4] Minoru S, Kazushige K, Hirotoshi I. Experimental consideration on head form impact test for pedestrian protection[J]. SAE Paper, 1993, 0095(1):79-85.
[5] Koji M, Janusz K, Toshiki A. Influences of vehicle shape on injuries in vehicle-pedestrian impact [J]. JSAE Convention Proceedings, 1999, 30(4):55-60.
[6] Koji M, Hideli Y, Janusz K. Relation between head and impact location in car-pedestrian impacts [A]. In: JSAE Ed. Conference of Vehicle Technology[C]. Yokohama: Japan Sven Glade H,1999,67-72.
[7] Koji M, Hideki Y, Janusz K. The study of injury risk to the pedestrian head based on head form impact test[A]. In: JSAE Ed. Spring Convention Proceedings[C]. Yokohama: Japan Sven Glade H, 1993, 9-12.
[8] Yasuki M, Tetsuo M, Toshiyuki A, et al. Development of FEM Models of Imp actors for Pedestrian Impact Test[A]. In: JSAE Ed. Spring Convention Proceedings[C]. Yokohama: Japan Sven Glade H, 1999,9-12.
[9] Akihiko A. Development of pedestrian dummy and body structure for reducing pedestrian injury [J]. Vehicle Technology. 1999, 53(11):60-64.(in Japanese)
[10] Suguru Y, Norio I, Akio T, et al. Development of a body structure for reducing pedestrian injury [A]. In: JSAE Ed. Spring Convention Proceedings[C]. Yokohnma:Japan Sven Glade H, 1999,1-4.
[11] Ruan J S, Khalil T, King A L. Human head dynamic response to side impact by finite element modeling[J]. Journal of Biomechanical Engineering. 1991, 113(2):276-283.
[12] Kazunari U, John W. Melvin. Finite element model study of head impact based on hybrid Ⅲ head acceleration: the effects of rotational and translational acceleration[J]. Journal of Biomechanical Engineering, 1995, 117(2):319-328.
[13] Ruan J S, Khalil T, King A L. Dynamic response of the human head to impact by threedimensional finite element analysis[J]. Journal of Biomechanical Engineering, 1994, 116(3):44-51.
[14] Tsuyoshi Y. Application of crash simulation to vehicle development[J]. Vehicle Technology.1998, 52(4):43-48.(in Japanese)
[15] YANG Su, TANG Heng-ling, KANG Buo-yu. Dynamic of Machine Tool[M]. Beijing: Mechanical Industry Press, 1983.(in Chinese)
[16] CHENG Xiang-sheng. Applying theory of Plates and Shells[M]. Jinan: Shandong Science and Technology Press, 1989.(in Chinese)
[17] JIAO Da-bin, WU Wen-Zhou, LEI Gang, et al.. Test analysis of mechanics model of head skull [C]. Development of Biomechanics. Beijing: Science and Technology Press, 1993.(in Chinese)
[18] JIAO Da-bin, WU Wen-zhou, YANG Gui-tong. Mechanical analysis of human skull under impact [J]. Journal of China Biomedicine Engineering, 1992, 13(9): 141-149.(in Chinese)