中文摘要：

提出一种用于承压界面接触状态超声评价的粗糙界面微观模型。通过对承压粗糙表面微观特性理论分析,建立粗糙界面微观形貌参数与承压界面超声响应之间的关系。开展三种不同粗糙度承压铝界面超声透射试验,得到加载和卸载过程界面透射系数随压力变化关系,进而获得界面接触刚度和非线性系数。研究表明,在较小压力情况下,超声非线性系数对承压界面接触状态评价具有更高的灵敏度。通过对试验检测数据进行非线性最小二乘拟合处理,确定出接触界面微观形貌特征参数,进而计算出接触界面声学特性指标。理论计算得到声学特性与试验结果吻合较好,证明粗糙表面微观模型用于非完好界面声响应预测的有效性。

英文摘要：

A micromechanical model of rough surface for an interface between two solids is presented to evaluate the acoustic properties during loading and unloading cycle.By theoretical description of the micromechanics of rough,contacting surfaces under static normal loads,the relationship between the topographic parameters of the rough surface and the acoustic response of pressure interface are established.Ultrasonic experiments are performed on three different interfaces formed by aluminum surfaces with different levels of roughness.The ultrasonic transmission coefficient from the interface is measured during loading and unloading cycles as a function of pressure,from which the ultrasonic interfacial contact stiffness and nonlinear coefficient are obtained.It is shown that the nonlinear coefficient is more sensitive to contact variation of interface under low loads.The topographic parameters of interface parameters are obtained by fitting measured transmission coefficients using nonlinear least squared minimization method.Using obtained parameters,the acoustic properties of interface are calculated.The theoretical acoustic properties are agreed well with the experimental results,and it is demonstrating the capability of the micromechanical model of rough surface in predicting the ultrasonic responses of imperfect interfaces.