摘要
传统的结合面研究多基于光滑刚性平面与等效粗糙表面接触假设,忽略了结合面上微凸体侧向接触及相邻微凸体之间的相互作用,这导致理论模型与实际结合面存在较大出入.针对承受法向静、动态力的机械结合面,从微观上研究了微凸体侧向接触及相互作用的接触能耗.将法向静、动态力分解为法向分力和切向分力,获取弹性/弹塑性/塑性阶段考虑微凸体侧接触及相互作用的加、卸载法向分力-变形和切向分力-位移的关系.通过力的合成定理,从而获取加、卸载法向合力与总变形之间的关系,由于法向分力产生的塑性变形及切向分力产生的摩擦,导致加载、卸载法向合力-总变形曲线存在迟滞回线.通过对一个加、卸载周期内的法向合力-总变形曲线积分,获得一个周期的微凸体接触能耗,包括应变能耗及摩擦能耗.仿真分析表明:微凸体在3个阶段的能耗均随变形的增大而非线性增大.微凸体侧向接触角度越大,能耗越大,且在弹性阶段最为明显.在弹性阶段,仅存在侧向的摩擦能耗,故结合面在低载荷作用下必须采用双粗糙表面假设.在塑性阶段,由于微凸体接触能耗为应变能耗,且接触角对其能耗影响甚微,故结合面在大载荷作用下可采用单平面假设对其进行研究.相对于KE和Etsion模型,本文提出的模型与Bartier的实验结果更吻合.
The traditional studies about a mechanical interface were mostly based on the assumption that a smooth rigid plane contacts with an equivalent rough surface,which ignored the lateral contact and interaction between asperities,so there has a serious error in those theoretical models.Aimed at an interface bearing normal static and dynamic force,the energy dissipation was studied from a micro level,which considered the lateral contact and interaction between asperities.The normal force can be divided into a normal component of force and a tangential component of force.The relation between the normal component and the deformation,and the relation between the tangential component and the displacement can be gotten during loading/unloading in the elastic stage,elastic-plastic stage,and plastic stage,respectively.According to the composition of forces,the relation between the normal force and total deformation can be derived.Because of the plastic deformation and friction between asperities,the curves of the loading and the unloading not coincide,and there is a hysteresis loop.One cycle of energy dissipation can be calculated by integrating the area of the hysteresis loop,which includes the strain energy dissipation and the friction energy dissipation.The simulation analysis shows that:the energy dissipation nonlinear increases with the increase of the deformation.The bigger contact angles the more energy dissipation,and it's the most obvious in the elastic stage.There are only the friction energy dissipation in the elastic stage,so under the low loads must use the assumption of double rough surfaces.In the plastic stage,there are only the strain energy dissipation,and the e_ects of the contact angle on the energy dissipation are very little,so under the heavy loads can use the assumption of the single rough surface to study the mechanical interface.Comparing with the KE and Etsion models,our proposed model is well agreed with the Bartier's experiments.
作者
高志强
傅卫平
王雯
康维超
吴洁蓓
刘雁鹏
Gao Zhiqiang;Fu Weiping;Wang Wen;Kang Weichao;Wu Jiebei;Liu Yanpeng(School of Mechanical and Precision Instrument Engineering,Xi’an University of Technology,Xi’an 710048,China)
出处
《力学学报》
EI
CSCD
北大核心
2017年第4期858-869,共12页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金(51275407
51475363)
陕西省自然科学基础研究计划(2015JM5246)资助项目
关键词
结合面
微凸体
侧向接触
相互作用
能耗
interfaces
asperity
lateral contact
interaction
energy dissipation
