RJAV vol XII issue 2/2015 155 ISSN 1584-7284 Numerical Study Regarding the Influence of Material Components for a Booster - Ultrasonic Horn Assembly on the Natural Frequency Marian-Dumitru NEDELONI “Eftimie Murgu” University of Resita, Traian Vuia Square, No. 1-4, 320085, Resita, Romania, m.nedeloni@uem.ro Cornel HAŢIEGAN “Eftimie Murgu” University of Resita, Traian Vuia Square, No. 1-4, 320085, Resita, Romania, c.hatiegan@uem.ro Ovidiu VASILE “Politehnica” University of Bucharest, 313 Splaiul Independentei, 060042, Bucharest, Romania, ovidiu_vasile2002@yahoo.co.uk Codruţa-Oana HAMAT “Eftimie Murgu” University of Resita, Traian Vuia Square, No. 1-4, 320085, Resita, Romania, c.hamat@uem.ro Cristian FĂNICĂ “Eftimie Murgu” University of Resita, Traian Vuia Square, No. 1-4, 320085, Resita, Romania, c.fanica@uem.ro Nicoleta GILLICH “Eftimie Murgu” University of Resita, Traian Vuia Square, No. 1-4, 320085, Resita, Romania, n.gillich@uem.ro Abstract: - The paper presents the simulation results of a booster - ultrasonic horn assembly. The ultrasonic horn shape is exponential and for the analyzed assembly was chosen different materials. Such an ultrasonic horn can be used in the composition of an experimental stand for experimental development of cavitation erosion of materials. By simulating the entire assembly with SolidWorks program, the aim is to see the material components influence of the assembly respectively the selection of material whose natural frequency depending on mode shapes, will range around the 20 kHz value. At this value the ultrasonic horn and therefore the experimental stand will operate correctly. Keywords: - Numerical study, booster - ultrasonic horn assembly, natural frequencies 1. INTRODUCTION For a structure without defects respectively with defects, the natural frequency values are different [1]. One way to identify a specific defect in an elastic structure is to determine and interpret its natural frequency changes [2, 3]. Such researches have been reported by various authors [4]-[8], where beams or solids like plates were analyzed. Damage can be assessed in the same way for structures composed of different materials, as the booster (mechanical transformer) - ultrasonic horn assembly is. This system is analyzed in the current paper. Generally, an ultrasonic horn or sonotrode may be used in various applications [9]-[14], one of that being the employment in the composition of a vibratory apparatus for testing the cavitation erosion of materials [15]. Such a vibratory apparatus can operate in some important parameters such as [16]:  The natural frequency, between the values: 20 ± 0.5 kHz;  The amplitude, with values between 50÷60 μm. For experimental research in the laboratory, regarding the resistance of metallic materials to cavitation erosion [17]-[19], a vibratory apparatus can operate at least 1000 hours. An important component is the ultrasonic horn, which can be used in practice several times and can run at its natural frequency for ~200 hours.