Monte Carlo simulation of weldment fatigue strength: Fid-Bau Portal

Monte Carlo simulation of weldment fatigue strength

Park, S.K. / Lawrence, F.V.

AbstractThe fatigue strength of constructional steel weldments is predicted using a Monte Carlo simulation which estimates the mean fatigue strength and its expected uncertainty at long lives. The underlying analytical model is at present solely based on fatigue crack initiation and early crack growth and is restricted to long-life applications. Several different kinds of fatigue variables are considered: applied or induced bending stresses, notch severity, notch-root residual stresses, and notch-root mechanical properties. Each of the fatigue variables is treated as a random variable, and its uncertainty is modeled by an appropriate probability distribution function based on laboratory observations. Simulations of constructional steel weldment fatigue strength are compared with laboratory test results on cruciform weldments and similar recent fatigue data reported in the literature.The Monte Carlo simulation also permits one to estimate the contribution of each fatigue variable to the overall uncertainty in fatigue strength and thus determine the economic merits of reducing the uncertainty in any one of the fatigue variables to improve the design fatigue strength.