TY - GEN
T1 - Experimental investigation and model analysis of uncertain loading effect on fatigue crack growth
AU - Lu, Zizi
AU - Xu, Jifeng
AU - Liu, Yongming
PY - 2012
Y1 - 2012
N2 - An integrated experimental and simulation approach is proposed to study the effect of loading uncertainties on the fatigue crack growth behavior of Al 7075-T6. Various loading histories, including constant amplitude loadings, single overload block loadings, and deterministic and random variable spectrum loadings are used in the current investigation. Multiple specimen tests are performed and statistical analysis is used to extract the probability distribution of crack size and fatigue life. A previously developed small time scale model is used as a mechanism model to explain the fatigue crack growth behavior under random variable amplitude loadings. Monte Carlo simulation is used for the probabilistic fatigue life prediction. Model predictions are compared with the experimental observations for model validation. It is observed that the effect of uncertain loading is different under different loading spectra. For some cases, the uncertainties of loadings have no major impact on the probabilistic life distribution. For other cases, loading uncertainties have significant impact on the scattering of the life distribution. Model analysis indicates that this behavior is mainly due to the scattering of crack opening stresses produced under different variable amplitude loading spectra.
AB - An integrated experimental and simulation approach is proposed to study the effect of loading uncertainties on the fatigue crack growth behavior of Al 7075-T6. Various loading histories, including constant amplitude loadings, single overload block loadings, and deterministic and random variable spectrum loadings are used in the current investigation. Multiple specimen tests are performed and statistical analysis is used to extract the probability distribution of crack size and fatigue life. A previously developed small time scale model is used as a mechanism model to explain the fatigue crack growth behavior under random variable amplitude loadings. Monte Carlo simulation is used for the probabilistic fatigue life prediction. Model predictions are compared with the experimental observations for model validation. It is observed that the effect of uncertain loading is different under different loading spectra. For some cases, the uncertainties of loadings have no major impact on the probabilistic life distribution. For other cases, loading uncertainties have significant impact on the scattering of the life distribution. Model analysis indicates that this behavior is mainly due to the scattering of crack opening stresses produced under different variable amplitude loading spectra.
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M3 - Conference contribution
AN - SCOPUS:84881451874
SN - 9781600869372
T3 - Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
BT - 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
T2 - 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
Y2 - 23 April 2012 through 26 April 2012
ER -