蚯蚓爬行的生物力学分析与数值计算  

BIOMECHANICAL ANALYSIS AND NUMERICAL CALCULATION OF EARTHWORM CRAWLING

作　　者：刘芳[1] 施卫平[1] 任露泉[2] 

机构地区：[1]吉林大学数学学院,长春130012 [2]吉林大学工程仿生教育部重点实验室,长春130022

出　　处：《力学学报》2010年第5期951-956,共6页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金项目(10972089)和国家自然科学基金重点项目(50635030)资助~~

摘　　要：蚯蚓是典型的多体节软体动物.从生物力学的角度,分析了蚯蚓在静止和运动状态下的体壁应力,又分析了蚯蚓爬行过程中的变形以及与地面之间的摩擦力,给出了蚯蚓在地表爬行的动力学模型.数值计算了一定质量范围的蚯蚓在静止和运动状态下体壁承受的最大应力和动力学模型方程,得到蚯蚓爬行的平均速度与质量的关系.计算结果与实验测量值基本一致.Earthworm is a typical multi-body segment and soft-bodied animal.The earthworm crawls forward by the alternating contraction and relaxation of circular and longitudinal muscles.The setae of underbelly are important movement organs.The setae are controlled by the special muscles and they can protrude from or retract into the body wall associating with the movement state.When an earthworm is in the cavity or on the ground,the setae support its body.When the setae protrude from body wall,the friction will increase;while when the setae retract into the body wall,the friction will decrease.In this paper,from a biomechanical point of view we analysis the tensile stress of the body wall during rest and peristaltic crawling,and calculate the body wall stress and crawling speed for a certain range of earthworm mass.The volume of a segment with the length l and the radius r is V=πr^2l.The volume will be considered to be always unchanged during the body wall deformation,then we get dr/dl=-r/2l.This shows that with 1%of the circular muscles shortening,there will be 2%elongation of the longitudinal muscles.Numerical results are almost consistent with experimental values.We also describe the deformation coupled with a simple friction model during peristaltic crawling.The dynamic equation of earthworm crawling is presented and calculated numerically.Numerical results show that the mean speed of earthworm crawling for different masses is consistent with experimental value.Numerical results also show that the relationship between the mean speed of an earthworm and its mass is consistent with experimental function v=3.8m^（0.33）.

关 键 词：蚯蚓 体节 体壁应力 摩擦力 爬行速度 

分 类 号：G804.6[文化科学—运动人体科学]