Issue 38

M.A. Meggiolaro et alii, Frattura ed Integrità Strutturale, 38 (2016) 67-75; DOI: 10.3221/IGF-ESIS.38.09 74 Figure 5 : Original points from an idealized A 3     stress path (  markers), and outputs from the MRF (square and triangular markers), considering mean stress effects. C ONCLUSIONS he Multiaxial Racetrack Filter (MRF) is an efficient amplitude filter applicable to multiaxial histories and fatigue damage models based on invariants or on the critical-plane approach. The MRF is able to filter out low-amplitude events, significantly decreasing the computational cost of subsequent multiaxial fatigue-damage calculations. In this work, mean/maximum stress effects were incorporated into the MRF. The proposed variable filter amplitudes allowed the algorithm to efficiently filter out events based on their damage parameter. In this way, lower filter amplitudes are automatically used for tensile histories, and higher filter amplitudes for compressive ones, optimizing the filter efficiency without neglecting significant damaging events. R EFERENCES [1] Fuchs, H.O., Nelson, D.V., Burke, M.A., Toomay, T.L., Shortcuts in Cumulative Damage Analysis, SAE Automobile Engineering Meeting Paper 730565 (1973). [2] Castro, J.T.P., Meggiolaro, M.A., Fatigue Design Techniques (in 3 volumes), CreateSpace, Scotts Valley, CA, USA (2016). [3] Meggiolaro, M.A., Castro, J.T.P., An improved multiaxial rainflow algorithm for non-proportional stress or strain histories - part I: enclosing surface methods, Int. J. Fatigue, 42 (2012) 217-226. doi:10.1016/j.ijfatigue.2011.10.014 [4] Meggiolaro, M.A., Castro, J.T.P., Wu, H., Invariant-based and critical-plane rainflow approaches for fatigue life prediction under multiaxial variable amplitude loading, Procedia Engineering, 101 (2015) 69-76. doi: 10.1016/ j.proeng.2015.02.010 [5] Meggiolaro, M.A., Castro, J.T.P., Wu, H., Shortcuts in multiple dimensions: the multiaxial racetrack filter, Frattura ed Integrità Strutturale, 33 (2015) 368-375. doi: 10.3221/IGF-ESIS.33.40 [6] Wu, H., Meggiolaro, M.A., Castro, J.T.P., Validation of the multiaxial racetrack amplitude filter, Int. J. Fatigue, 87 (2016) 167-179. doi: 10.1016/j.ijfatigue.2016.01.016 T