金属橡胶作为一种新型阻尼材料,其原材料及加工工艺具有一定特殊性.基于材料的细观结构特征,选取了金属丝螺旋卷作为金属橡胶的基本微元体结构,并以圆柱压缩螺旋弹簧理论为基础,分别建立了横向和纵向排列微元体结构的刚度.鉴于库仑摩擦模型,分别建立三种接触状态螺旋卷接触对的力学模型.考虑整个加工工艺流程的特点,分析了不同接触状态数目变化规律,建立了金属橡胶迟滞特性本构模型.从理论上解释了金属橡胶迟滞特性的特点,以及刚度和阻尼非线性的产生机理.最后,通过对比不同相对密度金属橡胶试件的理论和试验结果,验证了理论模型的适用性.本模型从螺旋卷微元体结构上描述了金属橡胶迟滞特性,为工程上预测和分析金属橡胶的刚度、阻尼特性和设计金属橡胶产品提供了有效的理论基础.
Metal rubber(MR) material is a new-type of damping material.Its raw material and fabrication process have same unique features. Wire helix is considered as the unit cell geometry of MR.Combining cylindrical compression coil spring theory,a mechanical model is established for individual wire helix which is located in the horizontal or longitudinal direction.Three contact statuses are analyzed for the neighboring helixes and mechanical models are derived for these cases according to the Kulun model.The arrangement and the spatial distribution of the microelements are assumed to be located evenly and periodically inside the MR.A mathematic model is established to characterize the damping behavior of MR.It came from the unit cell geometry and the fabrication process of MR materials.It is easy to explain the mechanism of hysteresis loop and the nonlinear stiffness and damping characteristic of MR by analyzing contact states and contact number of unit cell wire helixes.Finally,a comparison is made between theoretical results and experimental results.This model is valuable for the analysis of the material mechanics and the design of MR.It provides theoretical support for the further engineering application of MR in the field of vibration reduction.