scholarly journals Parameter identification in tidal models with uncertain boundary conditions

1990 ◽  
Vol 4 (3) ◽  
pp. 193-208 ◽  
Author(s):  
P. G. J. ten Brummelhuis ◽  
A. W. Heemink
Keyword(s):  
Boundary Conditions ◽  
Parameter Identification ◽  
Uncertain Boundary

scholarly journals Influence of the Parameterization in the Interval Solution of Elastic Beams

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Stefano Gabriele ◽  
Valerio Varano
Keyword(s):  
Boundary Conditions ◽  
Closed Form ◽  
Interval Analysis ◽  
Elastic Beam ◽  
Elastic Beams ◽  
Analysis Theory ◽  
Set Intersection ◽  
Interval Solution ◽  
Uncertain Boundary

We are going to analyze the interval solution of an elastic beam under uncertain boundary conditions. Boundary conditions are defined as rotational springs presenting interval stiffness. Developments occur according to the interval analysis theory, which is affected, at the same time, by the overestimation of interval limits (also known as overbounding, because of the propagation of the uncertainty in the model). We suggest a method which aims to reduce such an overestimation in the uncertain solution. This method consists in a reparameterization of the closed form Euler-Bernoulli solution and set intersection.

Influence of uncertain boundary conditions and model structure on flood inundation predictions

2006 ◽  
Vol 29 (10) ◽  
pp. 1430-1449 ◽  
Author(s):  
Florian Pappenberger ◽  
Patrick Matgen ◽  
Keith J. Beven ◽  
Jean-Baptiste Henry ◽  
Laurent Pfister ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Model Structure ◽  
Flood Inundation ◽  
Uncertain Boundary

scholarly journals An Analytical Method for Crack Detection of Beams with Uncertain Boundary Conditions by a Concentrated Test Mass

2018 ◽  
Vol 4 (7) ◽  
pp. 1629
Author(s):  
Seyed Milad Mohtasebi ◽  
Naser Khaji
Keyword(s):  
Boundary Conditions ◽  
Crack Detection ◽  
Beam Theory ◽  
Element Model ◽  
Test Mass ◽  
Cracked Beam ◽  
Stationary Mass ◽  
Numerical Finite Element ◽  
Torsion Springs ◽  
Uncertain Boundary

The aim of this study is to introduce a method for crack detection and simultaneously assessing boundary conditions in beams. This study suggests a method based on the effect of a concentrated test mass on the natural frequency that is defined as a stationary mass, which can be located in different positions of the beam and cannot be separated from the beam. Timoshenko beam theory is used to calculate the frequencies. In this method, a beam with the desired number of cracks is modeled. The beam is divided into separated parts at crack section which are joined together by elastic weightless torsion springs, to avoid non-linearity effects, it is assumed that the crack is always open. At the first step, equations for a cracked beam are extracted by considering the spring boundary conditions. Then, to verify the equations, numerical finite element model is used. In this way, a new method is also applied to model the torsion springs in supports and it is shown that suggested model is acceptable. Eventually, the obtained responses are evaluated and the sources of errors are identified. To correct the existing errors, a modifying function is suggested. Finally, the inverse problem is solved.

Effects of Uncertainties in Boundary Conditions on Dynamic Characteristics of Industrial Plant Components

2014 ◽  
Author(s):  
Oreste S. Bursi ◽  
Giuseppe Abbiati ◽  
Luca Caracoglia ◽  
Md Shahin Reza
Keyword(s):  
Boundary Conditions ◽  
Dynamic Characteristics ◽  
Seismic Risk ◽  
Dynamic Properties ◽  
Fragility Curves ◽  
Structural Safety ◽  
Industrial Plant ◽  
Piping System ◽  
Uncertain Boundary ◽  
Plant Components

Seismic risk assessment of industrial plants is of paramount importance to ensure adequate design against earthquake hazards. Seismic vulnerability of industrial plant components is often evaluated through a fragility analysis to conform to structural safety requirements. Fragility curves of single components are usually developed by neglecting the effect of actual boundary conditions. Thus, an incorrect evaluation of individual fragility curves can affect the overall fragility curve of a system. This may lead to “erroneous” seismic risk evaluation for a plant in comparison with its real state. Hence, it is important to study the effect of uncertainties, introduced at the boundaries when coupling effects are neglected, on the dynamic characteristics of a system. Along this line, this paper investigates the effects of uncertain boundary conditions on the probability distributions of the dynamic properties of a simple chain-like system with increasing number of degrees of freedom. In order to describe the uncertain boundary condition, a modified version of the well-known β distribution is proposed. Subsequently, the Analytical Moment Expansion (AME) method is employed to estimate the statistical moments of the output random variables as an alternative to more computationally-demanding Monte Carlo simulations. Finally, a preliminary extension of the proposed approach to a realistic piping system connected to a class of broad/slender tanks is discussed.

Vibration-based estimation of axial force for a beam member with uncertain boundary conditions

2013 ◽  
Vol 332 (4) ◽  
pp. 795-806 ◽  
Author(s):  
Suzhen Li ◽  
Edwin Reynders ◽  
Kristof Maes ◽  
Guido De Roeck
Keyword(s):  
Boundary Conditions ◽  
Axial Force ◽  
Uncertain Boundary
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