蜂窝复合材料超声加工复合变幅杆的设计

Design of Composite Horn for Ultrasonic Machining of Honeycomb Composite Materials

在蜂窝复合材料的超声加工中,针对阶梯形变幅杆截面交界处突变存在应力集中,不适合在高振幅的情况下工作的情况,兼顾形状因素与放大系数,设计了指数过渡段、圆锥过渡段、悬链过渡段阶梯形变幅杆。通过波动方程建立变幅杆参数方程,计算了变幅杆的谐振长度、放大倍数、节点位置。利用ANSYS软件分别对指数过渡段、圆锥过渡段、悬链过渡段阶梯形变幅杆进行有限元分析,通过调节变幅杆的长度对变幅杆进行优化。计算表明,优化后变幅杆的频率误差降低,指数过渡段、圆锥过渡段、悬链过渡段阶梯形变幅杆的谐振频率分别为20.194 kHz,19.999 kHz,19.633 kHz,放大倍数分别为5.506,4.460,6.16,最大应力分别为38.976 MPa,30.399 MPa,55.593 MPa。将简单形状变幅杆与阶梯形变幅杆相结合,既有较大的放大系数又避免了应力集中。

In the ultrasonic processing of honeycomb composite materials,in view of the sudden stress concentration at the cross section junction of the stepped amplitude horn,which is not suitable for working in high amplitudes.Taking into account the shape factor and amplification factor,the stepped amplitude horn with exponential transition section,conical transition section and catenary transition section was designed,the parameter equation of the amplitude horn was established by the wave equation,and the resonant length,amplification factor and node position of the horn were calculated,the finite element analysis of the stepped amplitude horn in exponential transition section,conical transition section and catenary transition section was carried out by ANSYS software,and the amplitude horn was optimized by adjusting the length of the horn.The calculation shows that the frequency error of the amplitude horn after optimization is reduced,the resonant frequencies of the stepped amplitude horn in exponential transition section,conical transition section and catenary transition section are 20.194 kHz,19.999 kHz and 19.633 kHz,respectively,the amplification factors are 5.506,4.460 and 6.16 respectively,and the maximum stresses are 38.976 MPa,30.399 MPa and 55.593 MPa respectively.Therefore,the combination of simple amplitude horn and stepped amplitude horn not only has a large amplification factor,but also avoids stress concentration.