《Random Vibration Fatigue Analysis with LS-DYNA》.pdf

12th International LS-DYNA® Users Conference Simulation(2) Random Vibration Fatigue Analysis with LS-DYNA 1 2 Arnaud Ringeval , Yun Huang 1 CIMES, France 360 rue Marc Lefrancq, Les Ateliers Numériques, 59300 Valenciennes, France 2Livermore Software Technology Corporation 7374 Las Positas Road, Livermore, CA, 94551, United States Abstract Fatigue damage assessment for components under random cyclic loading is an important concern in engineering. A new feature of random vibration fatigue analysis has been implemented to LS-DYNA, to perform the structural fatigue ana lysis in a random vibration environment. This feature computes cumulative damage ratio and expected fatigue life for structures, based on the Palmgren -Miner’s rule of cumulative damage ratio and material’s S -N fatigue curve. A series of fatigue analysis me thods have been implemented. They include the Steinberg’s three band method, Dirlik method, Narrow band method, Wirsching method, Chaudhury and Dover method, Tunna method and Hancock method. Brief introduction of the analysis methods is provided. To facilitate post -processing of the fatigue analysis, a new binary plot file d3ftg has been implemented in LS-DYNA. This binary plot file provides fatigue analysis information including cumulative damage ratio, expected life, zero- crossing frequency, peak-crossing frequency and irregularity factor for the structure, based on the stress index adopted in the analysis and the load period. This f