Fatigue Under Combined High and Low Frequency Loads

2006 ◽  
Author(s):  
Wenbo Huang ◽  
Torgeir Moan
Keyword(s):  
Numerical Simulation ◽  
Fatigue Damage ◽  
Low Frequency ◽  
Flow Prediction ◽  
Non Gaussian ◽  
New Formula

Based on Gaussian load processes, a new formula suitable for evaluating the combined fatigue damage due to high and low frequency loads is derived. Then, by using of the Winterstein’s transformation, the developed formula is extended for the combination of non-Gaussian loads. The numerical simulation shows that the predicted damage by the derived formula is very simple to use and close to the rain-flow prediction.

A Practical Formulation for Evaluating Combined Fatigue Damage From High- and Low-Frequency Loads

2006 ◽  
Vol 129 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Wenbo Huang ◽  
Torgeir Moan
Keyword(s):  
Numerical Simulation ◽  
Fatigue Damage ◽  
Low Frequency ◽  
Flow Prediction ◽  
Non Gaussian ◽  
New Formula

Based on Gaussian load processes, a new formula suitable for evaluating the combined fatigue damage due to high- and low-frequency loads is derived. Then, by using of the Winterstein’s transformation, the developed formula is extended for the combination of non-Gaussian loads. The numerical simulation shows that the predicted damage by the derived formula is very simple to use and close to the rain-flow prediction.

Wave-Induced Fatigue Damage of Mooring Chain Under Combined Non-Gaussian Low and Wave Frequency Loads

2006 ◽  
Author(s):  
Zhen Gao ◽  
Torgeir Moan
Keyword(s):  
Fatigue Damage ◽  
Volterra Series ◽  
Low Frequency ◽  
Line Tension ◽  
Response Spectra ◽  
Wave Force ◽  
Wave Frequency ◽  
Mooring Line ◽  
Non Gaussian ◽  
Mooring Chain

This paper deals with the fatigue damage of catenary mooring chain under combined low frequency (LF) and wave frequency (WF) loads which are both non-Gaussian. The distribution of quasi-static LF mooring line tension is obtained by representing the slowly-varying wave force acting on the vessel as a second-order Volterra series and by taking into account the nonlinear relationship between the vessel motion and the resulting line tension. The dynamic WF tension distribution is estimated when both the drag and inertia forces on the mooring line are considered. Finally, with the narrow-band assumption for both the LF and WF response spectra, the total fatigue damage is approximated by the sum of the fatigue damages due to the WF tension process and the sum process of the WF tension envelope and the LF tension. The procedure is illustrated by considering of the mooring system of a semi-submersible. Short-term distributions of LF and WF line tensions are given and compared with the results from the linearized analyses with Gaussian tension. Relative LF and WF long-term contributions to the total fatigue damage from different sea states are also provided.

Non-Gaussian Wind Pressure on Prismatic Buildings. II: Numerical Simulation

2001 ◽  
Vol 127 (9) ◽  
pp. 990-995 ◽  
Author(s):  
Massimiliano Gioffrè ◽  
Vittorio Gusella ◽  
Mircea Grigoriu
Keyword(s):  
Numerical Simulation ◽  
Wind Pressure ◽  
Non Gaussian

Numerical simulation of seismic waves in porous media components

2021 ◽  
Vol 9 (1) ◽  
pp. 4-30
Author(s):  
M. Azeredo ◽  
◽  
V. Priimenko ◽  
Keyword(s):  
Numerical Simulation ◽  
Porous Medium ◽  
High Frequency ◽  
Seismic Waves ◽  
Computational Algorithm ◽  
Low Frequency ◽  
Physical Parameters ◽  
Mathematical Algorithm ◽  
Biot Equations ◽  
Attenuation And Dispersion

This work presents a mathematical algorithm for modeling the propagation of poroelastic waves. We have shown how the classical Biot equations can be put into Ursin’s form in a plane-layered 3D porous medium. Using this form, we have derived explicit for- mulas that can be used as the basis of an efficient computational algorithm. To validate the algorithm, numerical simulations were performed using both the poroelastic and equivalent elastic models. The results obtained confirmed the proposed algorithm’s reliability, identify- ing the main wave events in both low-frequency and high-frequency regimes in the reservoir and laboratory scales, respectively. We have also illustrated the influence of some physical parameters on the attenuation and dispersion of the slow wave.

Numerical Simulation to Detect Low-Frequency Squeal Propensity

2000 ◽  
Author(s):  
Franck Moirot ◽  
Antoine Nehme ◽  
Quoc Son Nguyen
Keyword(s):  
Numerical Simulation ◽  
Low Frequency
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