TY - RPRT
T1 - Fatigue Analysis of a Mono-Tower Platform
AU - Kirkegaard, Poul Henning
AU - Sørensen, John Dalsgaard
AU - Brincker, Rune
N1 - PDF for print: 23 pp.
PY - 1988
Y1 - 1988
N2 - In this paper, a fatigue reliability analysis of a Mono-tower platform is presented. The failure mode, fatigue failure in the butt welds, is investigated with two different models. The one with the fatigue strength expressed through SN relations, the other with the fatigue strength expressed through linear-elastic fracture mechanics (LEFM). In determining the cumulative fatigue damage, Palmgren-Miner's rule is applied. Element reliability as well as systems reliability is estimated using first-order reliability methods (FORM). The sensitivity of the systems reliability to various parameters is investigated. The systems reliability index, estimated by using the fatigue elements with the fatigue strength expressed through SN relations, is found to be smaller than the systems reliability index estimated by using LEFM. It is shown that the systems reliability index is very sensitive to variations of the natural period, damping ratio, current, stress Spectrum and parameters describing the fatigue strength. Further, soil damping is shown to be significant for the Mono-tower.
AB - In this paper, a fatigue reliability analysis of a Mono-tower platform is presented. The failure mode, fatigue failure in the butt welds, is investigated with two different models. The one with the fatigue strength expressed through SN relations, the other with the fatigue strength expressed through linear-elastic fracture mechanics (LEFM). In determining the cumulative fatigue damage, Palmgren-Miner's rule is applied. Element reliability as well as systems reliability is estimated using first-order reliability methods (FORM). The sensitivity of the systems reliability to various parameters is investigated. The systems reliability index, estimated by using the fatigue elements with the fatigue strength expressed through SN relations, is found to be smaller than the systems reliability index estimated by using LEFM. It is shown that the systems reliability index is very sensitive to variations of the natural period, damping ratio, current, stress Spectrum and parameters describing the fatigue strength. Further, soil damping is shown to be significant for the Mono-tower.
KW - Reliability Analysis
KW - First-Order Reliability Methods
KW - FORM
KW - Sensitivity Analysis
KW - Fatigue Failure
KW - Random Loads
KW - Offshore
KW - Mono-Tower Platform
KW - Reliability Analysis
KW - First-Order Reliability Methods
KW - FORM
KW - Sensitivity Analysis
KW - Fatigue Failure
KW - Random Loads
KW - Offshore
KW - Mono-Tower Platform
M3 - Report
T3 - Fracture and Dynamics
BT - Fatigue Analysis of a Mono-Tower Platform
PB - Dept. of Building Technology and Structural Engineering, Aalborg University
CY - Aalborg
ER -