基于分形理论的结合面法向接触阻尼与损耗因子模型

Normal Contact Damping and Dissipation Factor Model of Joint Interfaces Based on Fractal Theory

基于结合面法向阻尼耗能机理及MB接触分形修正模型,提出了一种结合面法向接触阻尼模型及结合面间阻尼损耗因子模型。仿真结果表明,分形维数在较小范围内,法向阻尼与法向总载荷呈微凹弧非线性关系,且随着法向总载荷和分形维数的增大而减小,随着分形尺度参数的增大而增大;分形维数在较大范围内,法向阻尼与法向总载荷呈微凸弧非线性关系,且随着法向总载荷和分形维数的增大而增大,随着分形尺度参数的增大而减小。而结合面损耗因子与法向总载荷呈微凹弧非线性关系且随着法向总载荷的增大而减小,随着分形尺度参数的增大而增大,分形维数在较大值范围内,结合面损耗因子随其增大而增大。

Based on the modified MB fractal model and mechanism of contact normal damping dissipating energy, a fractal model of normal damping of joint interfaces was proposed. Furthermore, numerical simulation revealed that the micro concave nonlinear relation of normal damping versus dimensionless total normal load was very evident, which decreased with increasing fractal dimension and normal total load, and increased with increasing fractal scale parameter in the smaller fractal dimension. Besides, the micro convex nonlinear relation of normal damping versus dimensionless total normal load was also very evident, which increased with increasing fractal dimension and normal total load, and decreased with increasing fractal scale parameter in the larger fractal dimension. But the micro concave nonlinear relation of normal dissipation factor versus dimensionless total normal load was very evident, which decreased with increasing normal total load, and increased with increasing fractal scale parameter and fractal dimension.