摘要
受到舱外航天服手套(EVA glove)关节处余压(航天服内外的压差)和编织物挤压的影响,航天员舱外作业时手部力量下降明显,严重降低了力学工效。为了解航天员在舱外作业时手套余压对手部肌肉和关节的力学影响,本文对手部抓握动作的运动解剖学和生物力学特点进行了分析,建立了食指抓握模型,即指骨关节采用铰链连接,有7块肌肉作为手指抓握动力单元,并采用Hill肌肉模型计算。使用ANSYS建立了包含骨骼、肌肉在内的食指及手套的三维有限元静力模型,并验证了此模型。应用此模型计算戴有不同尺寸手套情况下的肌肉力,结果表明,在手套余压的影响下,要达到裸手正常抓握时手指对物体的压力,手指肌肉应力需增大到正常情况的5.4倍,手指抓握力大部分被用于克服手套余压的影响。且手套与手指的间隙越小,余压对手指肌肉的力学影响就越小。本文的研究结果对航天员手套设计提供了一定的理论依据。
The hand strength of astronauts,when they are outside the space capsule,is highly influenced by the residual pressure(the pressure difference between inside pressure and outside one of the suit) of extravehicular activity spacesuit glove and the pressure exerted by braided fabric.The hand strength decreases significantly on extravehicular activity,severely reducing the operation efficiency.To measure mechanical influence caused by spacesuit glove on muscle-tendon and joints,the present paper analyzes the movement anatomy and biomechanical characteristics of gripping,and then proposes a grip model.With phalangeal joint simplified as hinges,seven muscles as a finger grip energy unit,the Hill muscle model was used to compute the effects.We also used ANSYS in this study to establish a 3-D finite element model of an index finger which included both bones and muscles with glove,and then we verified the model.This model was applied to calculate the muscle stress in various situations of bare hands or hands wearing gloves in three different sizes.The results showed that in order to achieve normal grip strength with the influence caused by superfluous press,the finger's muscle stress should be increased to 5.4 times of that in normal situation,with most of the finger grip strength used to overcome the influence of superfluous pressure.When the gap between the finger surface and the glove is smaller,the mechanical influence which superfluous press made will decrease.The results would provide a theoretical basis for the design of the EVA Glove.
出处
《生物医学工程学杂志》
EI
CAS
CSCD
北大核心
2013年第4期767-771,共5页
Journal of Biomedical Engineering
基金
国家自然科学基金资助项目(51175021)
关键词
舱外航天服手套
手指模型
余压
有限元建模
EVA glove
Finger model
Residual pressure
Finite element modeling