Análise crítica operacional de um equipamento protótipo para ensaios de fadiga por flexão rotativa

Abstract

The application of fluctuating or repetitive stresses on materials causes fracture to occur at stresses much lower than those determined by static tensile or compression tests. This failure caused by alternating forces is known as fatigue. Fatigue testing equipment applies loads that vary cyclically to specimens and, therefore, measures their fatigue life under different loading conditions. The object of study of this work consisted of critically analyzing a prototype equipment for rotary bending fatigue testing based on the R. R. Moore model, covering aspects such as vibration promoted by the system, analyzing the behavior of the transverse load and verifying the load fixation system to the test body. In addition, static tensile and roughness tests were carried out on the specimen, starting the experimental part. After carrying out the previous steps, points with possible problems in prototype 1 and their respective modifications were listed, which were applied according to the availability of material, thus generating prototype 2. The compression spring was replaced by a threaded rod, the distribution bar of load and the bearing bushings were remodeled, a load cell was added to measure the load and the motor drive, which was previously direct, was modified with the addition of a frequency inverter. With the modifications made, new tests and analyzes were carried out to compare prototypes. The results obtained during the tests with the analyzes performed, show that the prototype equipment 2 had good responses to the modifications used, having a reduction in the variability of the life of the tested samples, however the level of vibration increased in relation to prototype 1. [resumo fornecido pelo autor]