基于DEM的振动激励下金属板材表面效应研究  

Study on surface effect of sheet metal with vibration excitation based on DEM

作　　者：王小焕 李小钊 曹秒艳[2,3] 胡晗 韩旭斌 王鹏 WANG Xiao-huan;LI Xiao-zhao;CAO Miao-yan;HU Han;HAN Xu-bin;WANG Peng(Pinggao Group Co.,Ltd.,Pingdingshan 467000,China;School of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,China;Hebei Light Structural Equipment Design and Manufacturing Technology Innovation Center,Yanshan University,Qinhuangdao 066004,China)

机构地区：[1]平高集团有限公司,河南平顶山467000 [2]燕山大学机械工程学院,河北秦皇岛066004 [3]燕山大学河北省轻质结构装备设计与制备工艺技术创新中心,河北秦皇岛066004

出　　处：《塑性工程学报》2021年第2期92-101,共10页Journal of Plasticity Engineering

基　　金：国家电网有限公司总部科技项目“126 kV真实灭弧室关键工艺技术研究及应用”。

摘　　要：为研究振动激励下金属板材表面效应产生机理,以金属板材真实表面形貌为基础,建立振动条件下金属板材剪切-摩擦理论模型,并基于离散元法(Discrete Element Method,DEM)对其振动剪切过程进行数值仿真,探讨了不同振动参数对剪切摩擦系数的影响规律。结果表明,振动激励条件下,金属板材剪切摩擦系数均值随着振动频率增加而减小,但其减小幅度随频率由低频向高频过渡时存在一个频率分界点。频率小于分界点时,剪切摩擦系数均值由接近静态摩擦系数值逐渐减小至接近该值的1/2;频率大于分界点值时,剪切摩擦系数迅速降低并逼近零值。剪切摩擦系数均值随振幅增加而减小,剪切摩擦系数减小的幅度主要取决于施加的振动激励的平均能流密度,且存在一个平均能流密度阀值,在阀值范围内,随能流密度增加,减摩效应不明显;超过阀值时,随能流密度增大,减摩趋势越加显著。最后展开了振动剪切试验,验证了DEM在滑动摩擦模拟中的有效性。To study the mechanism of surface effect of sheet metal with vibration excitation,based on the real surface morphology of sheet metal,a theoretical shear-friction model of sheet metal with vibration was established and the shear process with vibration was simulated by discrete element method(DEM).The influence law of different vibration parameters on shear friction coefficient was discussed.The results show that under the condition of vibration excitation,the mean value of shear friction coefficient of sheet metal decreases with the increase of vibration frequency.However,there is a frequency cut-off point when the vibration transits from low frequency to high frequency.When the frequency is less than cut-off point,the mean value of the shear friction coefficient decreases gradually from the value close to the static friction coefficient to half of the value;when the frequency is greater than cut-off point,the shear friction coefficient decreases rapidly and approaches zero.The mean value of shear friction coefficient decreases with the increase of amplitude,and the reduction range of shear friction coefficient mainly depends on the average energy flow density of the applied vibration excitation.There is an average energy flow density threshold,and the anti-friction effect is not obvious with the increase of energy flow density within the threshold range.When the threshold is exceeded,the anti-friction trend becomes more and more obvious with the increase of energy flow density.Finally,the vibration shear test was carried out to verify the effectiveness of DEM in sliding friction simulation.

关 键 词：离散元法 表面效应 振动 摩擦 

分 类 号：TG386.43[金属学及工艺—金属压力加工]