Improvement of Certain Composite Structures’ Quality by the Ultrasonic Field

This paper presents the activities carried out to improve the quality of certain composite structures by manufacturing them with the assistance of an ultrasonic field. As many composite materials use epoxy resins as base materials, an important problem was noted, namely their high curing time, as well as the problems of lack of adhesion and delamination, which are also known and experienced in the case of composite structures made with metallic materials as a support. The application of an ultrasonic field can successfully solve both problems. To demonstrate this improvement, the manufacturing of cylinders used in braking stands in the automotive industry was considered the main application. The proposed technology will be then extended to conveyor belts or to the manufacturing of other high-adhesion surfaces. This article presents the traditional method and the new ultrasonic field deposition technology. The design of the ultrasonic system is presented based on an analytical calculation, FEM modal analysis, followed by the construction of the ultrasonic system, as well as by bending tests and infrared thermography to demonstrate the advantages of presented method.