Eventos Anais de eventos
MecSol 2017
6th International Symposium on Solid Mechanics
DYNAMIC AND FATIGUE ANALYSIS: COMPARISON BETWEEN TIME AND FREQUENCY DOMAINS
Submission Author:
Juliano Carvalho da Silva Filho , RJ
Co-Authors:
Said Rocha, Jorge Alberto Rodriguez Duran, José Flávio Silveira Feiteira, Antonio Müller, Alencar Filho, Caio Diniz, Patrícia Maia, Romulo Pereira, Uile Silva, Priscila Mendes
Presenter: Uile Silva
doi://10.26678/ABCM.MecSol2017.MSL17-0055
Abstract
The improvement of criteria for the durability evaluation is a growing need in the automotive industry and is fundamental for an optimized product development. Often, the structures are submitted to a general dynamic load and analyzed with CAE tools, mainly by the finite element method. This paper discusses about methodologies for dynamic simulations analyses in time and frequency domain to evaluate the fatigue life, and presents a bench test to correlate with simulation results. The evaluate fatigue life in time domain, is determined from stress history in deterministic form, however in frequency domain, is determined by the response PSD (Power Spectral Density) and from spectral moments in the probabilistic form. The methodology has been applied in cantilever beam with a lumped mass in the free end, and exposed to a random unidirectional base excitation. Were realized a bench test with data acquisition of base and response acceleration by accelerometer, and the beam strain by strain gauges. The test data has been applied as input data for the dynamics simulation and its validation. For fatigue analysis the life was estimated by the Palmgren-Miner rule. The method of the load cycle counting is the main difference between time and frequency domain damage analysis. For the cycle counting in time domain the Simplified Rainflow method has been applied, and in frequency domain the cycle counting is presented by stress PDF (Probability Density Function) proposed by Dirlik. Afterwards, the results of fatigue life time achieved by both simulations domain were compared to the bench test result.
Keywords
Vibration, Durability, Random Fatigue, DYNAMIC SIMULATION
