涂层界面刚度的超声数值仿真检测
发布时间：2018-11-20 13:54
【摘要】：针对涂层结合界面刚度在非破坏条件下难以精确测量的问题,提出了一种超声检测特征参量表征刚度系数的方法。利用声波在n层各向同性介质中的反射、透射原理,结合界面的弹簧模型,建立了多层介质界面刚度系数的超声检测数学模型。基体选用钢、铸铁、铝合金,表面选用不同喷涂工艺得到的Al2O3陶瓷涂层,获得了不同界面刚度系数的超声反射频谱。仿真结果表明:分离界面和理想界面时,谐振频率都具有周期性,但周期大小不同;弱结合界面时,随着界面的刚度系数逐渐增加,谐振频率逐渐增多,这些谐振频率均向高频方向移动。与频率较高处相比,频率较低处的谐振频率随着刚度系数的增加向高频移动的速度更快。因此建立了第一个谐振频率与刚度系数之间的关系。在同一刚度系数下,由谐振频率与材料的特性阻抗关系获得如下规律:当涂层材料不变时,谐振频率随着基体特性阻抗的增大而增大;当基体材料不变时,谐振频率随着涂层特性阻抗的增大而减小。给出了以指数函数形式拟合的刚度系数与谐振频率的变化曲线。通过对该指数函数参数与材料特性阻抗之间关系的分析,获得了弱界面时谐振频率与刚度系数和材料特性阻抗三者之间的函数表达式。该方法为涂层复合材料弱界面的超声检测提供了理论支持。
[Abstract]:In order to solve the problem that it is difficult to accurately measure the interface stiffness of the coating under the condition of non-failure, a method to characterize the stiffness coefficient by ultrasonic testing characteristic parameters is proposed. Based on the principle of reflection and transmission of sound waves in n-layer isotropic medium and the spring model of interface, a mathematical model of ultrasonic testing for the stiffness coefficient of interface of multi-layer medium is established. Steel, cast iron, aluminum alloy and Al2O3 ceramic coating with different spraying process were used to obtain the ultrasonic reflection spectrum of different interface stiffness coefficients. The simulation results show that the resonant frequency is periodic when the interface is separated from the ideal interface, but the period is different. When the interface is weakly bonded, the resonant frequency increases with the increase of the stiffness coefficient of the interface, and these resonant frequencies all move to the high frequency direction. Compared with the higher frequency, the resonant frequency at the lower frequency moves faster to the high frequency with the increase of the stiffness coefficient. Therefore, the relationship between the first resonant frequency and the stiffness coefficient is established. Under the same stiffness coefficient, the relationship between the resonant frequency and the characteristic impedance of the material is obtained as follows: when the coating material is constant, the resonant frequency increases with the increase of the substrate characteristic impedance; When the substrate material is invariant, the resonant frequency decreases with the increase of the characteristic impedance of the coating. The variation curve of stiffness coefficient and resonance frequency is given in the form of exponential function. Based on the analysis of the relationship between the parameters of the exponential function and the material characteristic impedance, the functional expressions of resonance frequency, stiffness coefficient and material characteristic impedance at weak interface are obtained. This method provides theoretical support for ultrasonic detection of weak interface of coated composites.
【作者单位】： 景德镇陶瓷大学机械电子工程学院;
【基金】：国家自然科学基金(51305184;51565020) 江西省教育厅科技项目(GJJ150925)
【分类号】：TG174.453
，
本文编号：2345094
[Abstract]:In order to solve the problem that it is difficult to accurately measure the interface stiffness of the coating under the condition of non-failure, a method to characterize the stiffness coefficient by ultrasonic testing characteristic parameters is proposed. Based on the principle of reflection and transmission of sound waves in n-layer isotropic medium and the spring model of interface, a mathematical model of ultrasonic testing for the stiffness coefficient of interface of multi-layer medium is established. Steel, cast iron, aluminum alloy and Al2O3 ceramic coating with different spraying process were used to obtain the ultrasonic reflection spectrum of different interface stiffness coefficients. The simulation results show that the resonant frequency is periodic when the interface is separated from the ideal interface, but the period is different. When the interface is weakly bonded, the resonant frequency increases with the increase of the stiffness coefficient of the interface, and these resonant frequencies all move to the high frequency direction. Compared with the higher frequency, the resonant frequency at the lower frequency moves faster to the high frequency with the increase of the stiffness coefficient. Therefore, the relationship between the first resonant frequency and the stiffness coefficient is established. Under the same stiffness coefficient, the relationship between the resonant frequency and the characteristic impedance of the material is obtained as follows: when the coating material is constant, the resonant frequency increases with the increase of the substrate characteristic impedance; When the substrate material is invariant, the resonant frequency decreases with the increase of the characteristic impedance of the coating. The variation curve of stiffness coefficient and resonance frequency is given in the form of exponential function. Based on the analysis of the relationship between the parameters of the exponential function and the material characteristic impedance, the functional expressions of resonance frequency, stiffness coefficient and material characteristic impedance at weak interface are obtained. This method provides theoretical support for ultrasonic detection of weak interface of coated composites.
【作者单位】： 景德镇陶瓷大学机械电子工程学院;
【基金】：国家自然科学基金(51305184;51565020) 江西省教育厅科技项目(GJJ150925)
【分类号】：TG174.453
，
本文编号：2345094
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