Modelling Strength Degradation Phenomena and Inspections Used for Reliability Assessment Based on Maintenance Planning

2006 ◽  
Author(s):  
Y. Garbatov ◽  
C. Guedes Soares ◽  
D. Ok ◽  
Y. Pu ◽  
C. M. Rizzo ◽  
...  
Keyword(s):  
Time Variation ◽  
Probabilistic Models ◽  
Reliability Assessment ◽  
Strength Degradation ◽  
Probability Of Detection ◽  
Ship Hull ◽  
Time Dependent ◽  
Maintenance Planning

The work reviews different probabilistic models of strength degradation of steel ship hull structures considering time dependent corrosion phenomena. Different models of time variation of the degradation phenomena are analyzed as well as the probability of detection and different inspection methods associated with each phenomenon is discussed.

Magnetorheological Flow in Pipes: An Exploration of the Time-Variation of Herschel-Bulkley Parameters

2007 ◽  
Author(s):  
Mario F. Letelier ◽  
Juan S. Stockle ◽  
Dennis A. Siginer
Keyword(s):  
Magnetic Field ◽  
Velocity Field ◽  
Unsteady Flow ◽  
Yield Stress ◽  
Magnetic Fluid ◽  
Time Variation ◽  
Power Index ◽  
Time Structure ◽  
Time Dependent ◽  
Constitutive Parameters

In this paper it is analyzed the effects on the flow of the time-variation of Herschel-Bulkley model of fluid constitutive parameters. In this way, the influence of a varying magnetic field on the unsteady flow of a magnetic fluid is explored. Yield stress, viscosity and power index are assumed time-dependent. In particular, linear variations in time of these parameters are considered. The characteristics of the velocity field is analyzed for different values of the constants that determine the time structure of the constitutive parameters.

scholarly journals Probabilistic Space- and Time-Interaction Modeling of Mainshock Earthquake Rupture Occurrence

2020 ◽  
Author(s):  
Luis Ceferino ◽  
Anne Kiremidjian ◽  
Gregory Deierlein
Keyword(s):  
Seismic Hazard ◽  
Probabilistic Models ◽  
Spatial Interaction ◽  
Information Criterion ◽  
Passage Time ◽  
Time Dependent ◽  
Attractive Alternative ◽  
Earthquake Rupture ◽  
Time Interaction ◽  
Seismic Moment Release

ABSTRACT This article presents a probabilistic formulation for modeling earthquake rupture processes of mainshocks. A correlated multivariate Bernoulli distribution is used to model rupture occurrence. The model captures time interaction through the use of Brownian passage-time distributions to assess rupture interarrival in multiple sections of the fault, and it also considers spatial interaction through the use of spatial correlograms. The correlograms represents the effect of rupture nucleation and propagation. This model is proposed as an attractive alternative to existing probabilistic models because it (1) incorporates time and space interactions of mainshocks, (2) preserves the marginal distributions of interarrival times after including spatial rupture interactions, that is, model consistency, and (3) has an implicit physical interpretation aligned with rupture behavior observations. The proposed model is applied to assess the occurrence of large interface earthquakes in the subduction fault along the coast of Lima, Peru. The model matches well both the annual magnitude exceedance rates and the average seismic moment release in the tectonic region. The Akaike information criterion (AIC) test confirms that our model performs statistically better than models that do not capture earthquake space interactions. AIC also shows that the spherical correlogram outperforms the exponential correlogram at reproducing earthquake data. Finally, time-dependent seismic hazard in the region is calculated, and the results demonstrate that by accounting for recent earthquake occurrences, the inclusion of time-dependent effects can reduce the 30 yr seismic hazard by a factor of 4.

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