0000000000389073

AUTHOR

Christian Bucher

showing 6 related works from this author

First-passage problem for nonlinear systems under Lévy white noise through path integral method

2016

In this paper, the first-passage problem for nonlinear systems driven by $$\alpha $$ -stable Levy white noises is considered. The path integral solution (PIS) is adopted for determining the reliability function and first-passage time probability density function of nonlinear oscillators. Specifically, based on the properties of $$\alpha $$ -stable random variables and processes, PIS is extended to deal with Levy white noises with any value of the stability index $$\alpha $$ . Application to linear and nonlinear systems considering different values of $$\alpha $$ is reported. Comparisons with pertinent Monte Carlo simulation data demonstrate the accuracy of the results.

Mathematical optimizationPath integralMonte Carlo methodAerospace Engineering020101 civil engineeringOcean EngineeringProbability density function02 engineering and technologyLévy white noise0201 civil engineering0203 mechanical engineeringApplied mathematicsElectrical and Electronic EngineeringMathematicsFirst passageApplied MathematicsMechanical EngineeringWhite noiseFunction (mathematics)Nonlinear systemAlpha (programming language)020303 mechanical engineering & transportsControl and Systems EngineeringPath integral formulationNonlinear systemRandom variable
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Path integral method for first-passage probability determination of nonlinear systems under levy white noise

2015

In this paper the problem of the first-passage probabilities determination of nonlinear systems under alpha-stable Lévy white noises is addressed. Based on the properties of alpha-stable random variables and processes, the Path Integral method is extended to deal with nonlinear systems driven by Lévy white noises with a generic value of the stability index alpha. Furthermore, the determination of reliability functions and first-passage time probability density functions is handled step-by-step through a modification of the Path Integral technique. Comparison with pertinent Monte Carlo simulation reveals the excellent accuracy of the proposed method.

Nonlinear systemPath integral formulationCalculusNonlinear systemApplied mathematicsWhite noiseLevy white noiseSettore ICAR/08 - Scienza Delle CostruzioniFirst-passageMathematicsPath Integral method
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Ideal and physical barrier problems for non-linear systems driven by normal and Poissonian white noise via path integral method

2016

Abstract In this paper, the probability density evolution of Markov processes is analyzed for a class of barrier problems specified in terms of certain boundary conditions. The standard case of computing the probability density of the response is associated with natural boundary conditions, and the first passage problem is associated with absorbing boundaries. In contrast, herein we consider the more general case of partially reflecting boundaries and the effect of these boundaries on the probability density of the response. In fact, both standard cases can be considered special cases of the general problem. We provide solutions by means of the path integral method for half- and single-degr…

Monte Carlo methodMarkov processProbability density function02 engineering and technologyWhite noise01 natural sciencesBarrier crossingsymbols.namesake0203 mechanical engineeringStructural reliability0103 physical sciencesBoundary value problem010301 acousticsMathematicsApplied MathematicsMechanical EngineeringMathematical analysisFokker-Planck equationWhite noisePath integrationNonlinear system020303 mechanical engineering & transportsMechanics of MaterialsPath integral formulationsymbolsFokker–Planck equationRandom vibration
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Dynamic Finite Element analysis of fractionally damped structural systems in the time domain

2015

Visco-elastic material models with fractional characteristics have been used for several decades. This paper provides a simple methodology for Finite-Element-based dynamic analysis of structural systems with viscosity characterized by fractional derivatives of the strains. In particular, a re-formulation of the well-known Newmark method taking into account fractional derivatives discretized via the Grunwald–Letnikov summation allows the analysis of structural systems using standard Finite Element technology.

Finite element methodDiscretizationMechanical EngineeringMathematical analysisStructural systemStructural analysiComputational MechanicsCalculationViscoelasticityFinite element methodViscoelasticityFractional calculusStrainSimple (abstract algebra)Newmark-beta methodTime domainMathematics
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Innovative straight formulation for plate in bending

2017

In this paper it has been introduced an innovative formulation for evaluating the deflection function of a simply supported plate loaded by uniformly distributed edge moments. Framed into Line Element-less Method, this formulation allows the evaluation of solution in terms of deflection, through few lines of algorithm implemented by Mathematica software without resorting to any discretization neither in the domain nor in the boundary. Interesting savings in terms of time and computational costs are achieved. Results obtained by the proposed method are well contrasted by ones obtained by classical methods and Finite Element Method.

Line Element-less MethodDiscretizationbusiness.industryMechanical EngineeringPlate bendingMathematical analysis02 engineering and technologyStructural engineeringBending of plates01 natural sciencesFinite element methodComputer Science Applications010101 applied mathematicsHarmonic polynomial020303 mechanical engineering & transportsSoftware0203 mechanical engineeringDeflection (engineering)Modeling and SimulationGeneral Materials Science0101 mathematicsbusinessCivil and Structural EngineeringMathematicsComputers & Structures
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Efficient solution of the first passage problem by Path Integration for normal and Poissonian white noise

2015

Abstract In this paper the first passage problem is examined for linear and nonlinear systems driven by Poissonian and normal white noise input. The problem is handled step-by-step accounting for the Markov properties of the response process and then by Chapman–Kolmogorov equation. The final formulation consists just of a sequence of matrix–vector multiplications giving the reliability density function at any time instant. Comparison with Monte Carlo simulation reveals the excellent accuracy of the proposed method.

Mathematical optimizationSequenceMarkov chainPoisson proceMechanical EngineeringReliability (computer networking)Monte Carlo methodAerospace EngineeringOcean EngineeringStatistical and Nonlinear PhysicsProbability density functionWhite noiseWhite noiseCondensed Matter PhysicsPath IntegrationNonlinear systemNuclear Energy and EngineeringStructural reliabilityApplied mathematicsFirst passage problemRandom vibrationSettore ICAR/08 - Scienza Delle CostruzioniRandom vibrationCivil and Structural EngineeringMathematicsProbabilistic Engineering Mechanics
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