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**Harvard**

Johannesson, P., Svensson, T., Samuelsson, L., Bergman, B. och de Maré, J. (2009) *Variation mode and effect analysis: an application to fatigue life prediction*.

** BibTeX **

@article{

Johannesson2009,

author={Johannesson, Pär and Svensson, Thomas and Samuelsson, Leif and Bergman, Bo and de Maré, Jacques},

title={Variation mode and effect analysis: an application to fatigue life prediction},

journal={Quality and Reliability Engineering International},

issn={0748-8017},

volume={25},

issue={2},

pages={167-179},

abstract={We present an application of the probabilistic branch of variation mode and effect analysis (VMEA) implemented as a first-order, second-moment reliability method. First order means that the failure function is approximated to be linear around the nominal values with respect to the main influencing variables, while second moment means that only means and variances are taken into account in the statistical procedure. We study the fatigue life of a jet engine component and aim at a safety margin that takes all sources of prediction uncertainties into account. Scatter is defined as random variation due to natural causes, such as non-homogeneous material, geometry variation within tolerances, load variation in usage, and other uncontrolled variations. Other uncertainties are unknown systematic errors, such as model errors in the numerical calculation of fatigue life, statistical errors in estimates of parameters, and unknown usage profile. By treating also systematic errors as random variables, the whole safety margin problem is put into a common framework of second-order statistics. The final estimated prediction variance of the logarithmic life is obtained by summing the variance contributions of all sources of scatter and other uncertainties, and it represents the total uncertainty in the life prediction. Motivated by the central limit theorem, this logarithmic life random variable may be regarded as normally distributed, which gives possibilities to calculate relevant safety margins. },

year={2009},

keywords={probabilistic VMEA, fatigue life, life prediction safety factor},

}

** RefWorks **

RT Journal Article

SR Electronic

ID 87362

A1 Johannesson, Pär

A1 Svensson, Thomas

A1 Samuelsson, Leif

A1 Bergman, Bo

A1 de Maré, Jacques

T1 Variation mode and effect analysis: an application to fatigue life prediction

YR 2009

JF Quality and Reliability Engineering International

SN 0748-8017

VO 25

IS 2

SP 167

OP 179

AB We present an application of the probabilistic branch of variation mode and effect analysis (VMEA) implemented as a first-order, second-moment reliability method. First order means that the failure function is approximated to be linear around the nominal values with respect to the main influencing variables, while second moment means that only means and variances are taken into account in the statistical procedure. We study the fatigue life of a jet engine component and aim at a safety margin that takes all sources of prediction uncertainties into account. Scatter is defined as random variation due to natural causes, such as non-homogeneous material, geometry variation within tolerances, load variation in usage, and other uncontrolled variations. Other uncertainties are unknown systematic errors, such as model errors in the numerical calculation of fatigue life, statistical errors in estimates of parameters, and unknown usage profile. By treating also systematic errors as random variables, the whole safety margin problem is put into a common framework of second-order statistics. The final estimated prediction variance of the logarithmic life is obtained by summing the variance contributions of all sources of scatter and other uncertainties, and it represents the total uncertainty in the life prediction. Motivated by the central limit theorem, this logarithmic life random variable may be regarded as normally distributed, which gives possibilities to calculate relevant safety margins.

LA eng

DO 10.1002/qre.960

LK http://dx.doi.org/10.1002/qre.960

OL 30