摘要
应用离散元软件PFC2D建立了蚯蚓波纹体表与土壤界面动态行为仿真模型,对比分析了光滑和波纹试样的接触界面、接触力场和接触颗粒数以及滑动阻力,得出:当波纹表面的摩擦力与土壤颗粒对波纹凸起处的向后推力之和小于光滑表面的摩擦力时,波纹表面起到减阻作用;如果土壤颗粒对波纹表面凸起处的向后推力过大,波纹会起到增加阻力的作用。另外,试样运动时,波纹表面比光滑表面对土壤的扰动大。随着垂直载荷的增加,波纹表面和光滑表面的滑动阻力均增加,且波纹表面的降阻效果减弱;随着前进速度的增加,2种试样滑动阻力的增加,但波纹表面的滑动阻力的增长小于光滑表面,即速度高时波纹表面降阻明显。结果表明:蚯蚓非光滑表面的减阻能力与接触界面特性和外部条件有关。研究结果可为揭示非光滑表面的减阻机制提供研究方法和参考。
A simulation model of the interfacial dynamics between soil and earthworm surface was developed by PFC2Dsoftware.The contact interface,the contact force field,the contact particle number and contact sliding resistance of smooth surface and corrugated surface was analyzed and compared.The results show that,when the resultant force of the friction and the particle backward thrust on the corrugated surface is less than the friction on the smooth surface,the corrugated surface can reduce the resistance.If the particle backward thrust on the corrugated surface is too large,the corrugated surface increases the resistance.When moving forward,the corrugated surface disturbs the soil more than the smooth surface.As the vertical load increases,the sliding resistances of both smooth and corrugated surfaces increase,but the drag-reduction effect of the corrugated surface declines.The sliding resistance increases with the forward speed,but the increase trend of the corrugated surface is smaller than that of the smooth surface,and the drag-reducing effect of the corrugated surface is more obvious at high-speed.The results also show that the drag-reducing capability of the earthworm skin is related to the interfacial contact characteristics and externalconditions.This study provides the reference for revealing the drag-reduction mechanism of non-smooth surface.
出处
《吉林大学学报（工学版）》
EI
CAS
CSCD
北大核心
2010年第6期1609-1613,共5页
Journal of Jilin University:Engineering and Technology Edition
基金
国家自然科学基金重点项目(50635030)
高等学校博士学科点专项科研基金项目(20050183015)
关键词
工程仿生学
离散元
蚯蚓
接触界面
动态行为
滑动阻力
engineering biontcs
discrete element method
earthworm
contact interface
dynamic behavior
sliding resistance
