6533b7dcfe1ef96bd1272b05

RESEARCH PRODUCT

Stationary and non-stationary stochastic response of linear fractional viscoelastic systems

Giuseppe FaillaMario Di PaolaAntonina Pirrotta

subject

Markov chainDiscretizationStochastic processMechanical EngineeringMathematical analysisDegrees of freedom (statistics)Stochastic calculusAerospace EngineeringOcean EngineeringStatistical and Nonlinear PhysicsViscoelasticity Fractional calculus Stochastic input Non-stationary responseCondensed Matter PhysicsFractional calculusOperator (computer programming)Nuclear Energy and EngineeringSettore ICAR/08 - Scienza Delle CostruzioniLinear equationCivil and Structural EngineeringMathematics

description

Abstract A method is presented to compute the stochastic response of single-degree-of-freedom (SDOF) structural systems with fractional derivative damping, subjected to stationary and non-stationary inputs. Based on a few manipulations involving an appropriate change of variable and a discretization of the fractional derivative operator, the equation of motion is reverted to a set of coupled linear equations involving additional degrees of freedom, the number of which depends on the discretization of the fractional derivative operator. As a result of the proposed variable transformation and discretization, the stochastic analysis becomes very straightforward and simple since, based on standard rules of stochastic calculus, it is possible to handle a system featuring Markov response processes of first order and not of infinite order like the original one. Specifically, for inputs of most relevant engineering interest, it is seen that the response second-order statistics can be readily obtained in a closed form, to be implemented in any symbolic package. The method applies for fractional damping of arbitrary order α ( 0 ≤ α ≤ 1 ) . The results are compared to Monte Carlo simulation data.

10.1016/j.probengmech.2011.08.017http://hdl.handle.net/10447/63660