【摘要】 利用斜槽式结构进行模式转换能有效实现纵扭复合,其局限在于设计不合理会导致纵扭转换效率低下。通过分析纵波斜入射固-气界面的反射和折射特性,仿真不同斜槽结构下的变幅杆在其谐振状态下的纵扭转换效率,探究了斜槽的角度、宽度、个数、深度、长度等因素对纵扭模式转换效率的影响。仿真结果表明:存在最佳的斜槽角度和斜槽宽度,使得纵扭转换效率最大;斜槽个数的增加能明显提升纵扭转换效率,且最佳斜槽宽度随斜槽个数增大而减小;斜槽深度和斜槽长度越大,纵扭转换效率越大,但达到一定长度值时趋于稳定。进而,通过对优化设计后的斜槽式变幅杆进行试验测试,验证了该研究的有效性,试验条件下获得的纵振和扭转幅值分别为9.5μm和29μm。更多还原

【Abstract】 Ultrasonic horn with slanting slots can convert its motion mode from longitudinal vibration to torsional vibration, however, the conversion efficiency depends on the structure design. In order to improve the conversion efficiency, the reflection factors of longitudinal wave and transverse wave were derived under different incident angles and the effects of structural parameters of slanting slots on the conversion efficiency were analyzed by using the finite element method. The analysis results show that there are an optimum angle and width of the slanting slots to get the biggest conversion efficiency, the optimum value of the slanting slots’ width decreases with the increasing of the number of the slanting slots, the conversion efficiency increases with the increasing of the depth or length of the slanting slots but gets steady when the length reaches a certain value. At last, an optimized ultrasonic horn with slanting slots was designed to validate the effectiveness of the simulation results.The measured longitudinal amplitude and torsional amplitude of the ultrasonic horn are 9.5 μm and 29 μm respectively.更多还原