材料和几何形状对变幅杆固有频率的影响研究

Research on the Influence of Material and Geometry on the Natural Frequency of the Horn

超声复合加工的加工能力与变幅杆的振动特性有关,为了提升材料利用率,利用模态分析法对四种常用几何形状,及铝合金、钛合金和45钢三种材料的变幅杆进行了模态分析。结果表明:在理想轴向振动模态下,四种几何形状中,指数形的固有频率最高,其中钛合金指数形变幅杆的仿真频率与设计频率最接近;铝合金圆锥形变幅杆的频率与泊松比、密度呈负相关,与弹性模量的呈正相关;四种几何形状中,阶梯形变幅杆固有频率范围最宽,圆锥形变幅杆最窄。对于需要频繁更换工具头的超声系统可选用固有频率的范围较大的45钢阶梯形变幅杆。以上结论为超声复合加工中变幅杆选材提供了参考。

The processing ability of ultrasonic composite machining is related to the vibration characteristics of the horn.In order to improve the material utilization rate,the modal analysis method is used to analyze the horns of four common geometric shapes and three materials of aluminum alloy,titanium alloy and 45 steel.The results show that in the ideal axial vibration mode,the natural frequency of the exponential shape is the highest among the four geometric shapes,and the simulation frequency of the titanium alloy exponential horn is closest to the design frequency;the frequency of the aluminum alloy conical horn is negatively correlated with Poisson’s ratio and density,and positively correlated with the modulus of elasticity.Among the four geometric shapes,the stepped horn has the widest natural frequency range and the conical horn is the narrowest.For ultrasonic systems that require frequent tool head replacement,45 steel stepped horns with a larger natural frequency range can be used.The above conclusions provide a reference for the material selection of horn in ultrasonic composite processing.