机床地脚低速滑动界面法向刚度分形模型及试验验证

发布时间：2018-09-07 22:23

【摘要】：按照一个弹性微凸体的平均接触压强构筑微凸体顶端接触变形。计及动摩擦因数计算微凸体最初屈服的临界平均压强。采用以无阻尼自然角频率为自变量的功率谱密度函数,给出识别界面分形维数、特征长度的理论和试验方法。仿真结果表明:微凸体最初屈服的临界平均压强随着动摩擦因数的增加而变小;分形区域扩展因数随着分形维数的增加而减小;微凸体最大结合面积随着分形维数的增加呈现线性减小;增加动摩擦因数、面积比和特征长度都将衰减法向接触刚度;法向接触刚度随着分形维数、接触面积的比率、法向接触载荷或微凸体最大结合面积的增加而增强。按照有限元模拟对界面法向接触参数识别结果进行证明。考虑界面参数的有限元模型得到的动柔度、法向接触刚度数据与试验数据一致。
[Abstract]:The contact deformation at the top of an elastic microconvex is constructed according to the average contact pressure. The critical mean pressure of the initial yield of the microconvex is calculated taking into account the dynamic friction coefficient. Using the power spectral density function with undamped natural angular frequency as independent variable, the theory and test method of identifying fractal dimension and characteristic length of interface are given. The simulation results show that the critical mean pressure of initial yield of microconvex body decreases with the increase of dynamic friction coefficient, and the expansion factor of fractal region decreases with the increase of fractal dimension. The maximum bonding area of microconvex body decreases linearly with the increase of fractal dimension; with the increase of dynamic friction coefficient, the normal contact stiffness will be attenuated by the area ratio and characteristic length; the normal contact stiffness will decrease with fractal dimension, and the ratio of contact area will decrease with the increase of dynamic friction coefficient. The normal contact load or the maximum bonding area of the microconvex body is increased. The identification results of normal contact parameters of interface are proved by finite element simulation. The dynamic flexibility obtained by the finite element model considering interface parameters is consistent with the experimental data.
【作者单位】：三峡大学机械与动力学院;
【基金】：国家自然科学基金(51275273,51605255) 2016年三峡大学研究生科研创新基金(SDYC2016033)资助项目
【分类号】：O34;TG502.14

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