Numerical Evaluation of State of the Art Horn Designs for Rotary Ultrasonic Vibration Assisted Machining of Nomex Honeycomb Composite

Abstract

Ultrasonic horn plays vital role in achieving vibration amplitude suitable for efficient machining of advanced composites. Due to very high operating frequency of at least of ultrasonic machining system, horn may be subjected to high stresses leading to failure. Mechanical horn is designed to get optimum vibration amplification while keeping stresses in acceptable limits. In this research, state of the art ultrasonic horns were designed with same length and diameters at the transducer side and tool ends under similar operating conditions. All standard and hybrid ultrasonic horns, including some new designs, suitable for machining applications were evaluated through finite element analysis. Modal analysis was performed for computing axial modal frequencies, whereas harmonic analysis was carried out to determine vibration amplitude, stresses and factor of safety. The performance of state of the art ultrasonic horn designs were later compared in terms of vibration amplification, stresses and operating life. The axial modal frequency and amplitude of vibration achieved by barrel, cylindrical-double conical and hollow exponential horns were observed to be greater as compared to the step horn, however the former were prone to greater stress concentrations and low operating life. Reasonably higher vibration amplification, factor of safety and low stresses were achieved by Bezier, cylindrical-catenoidal, cylindrical-Bezier, step-conical, step-catenoidal, step-Bezier, double conical, multistep and multistep-conical horn designs. Remarkably, circular hollow exponential and multistep-conical ultrasonic horns were observed to achieve vibration amplification, factor of safety and operating life higher than that of commercially available step horn.

Fabrication of Al-6061/SiC Nano Composite Material Through Ultrasonic Cavitation Technique and Its Analysis

“…Additionally, it can develop protective oxide scales on its surface in various types of chemical, acidic, marine, and industrial environments at both low and elevated temperatures. Physical properties and chemical composition of Ti 6Al-4V data sheet were obtained from MAHER company, U.K. as displayed in Table 1 and 2. Stepped horns were chosen for this work over other types of horns because they are easy to construct, manufacture and produce the most vibration amplification [21]. Thehorn's diameter and length were used, as indicated in Figure 1.…”