6533b7dbfe1ef96bd1271065

RESEARCH PRODUCT

Prestress and experimental tests on fractional viscoelastic materials

Mario Di PaolaVincenzo FioreFrancesco Paolo PinnolaAntonino Valenza

subject

Settore ING-IND/22 - Scienza E Tecnologia Dei MaterialiRelaxation test fractional calculus viscoelasticitySettore ICAR/08 - Scienza Delle Costruzioni

description

Creep and/or Relaxation tests on viscoelastic materials show a power-law trend. Based upon Boltzmann superposition principle the constitutive law with a power-law kernel is ruled by the Caputo’s fractional derivative. Fractional constitutive law posses a long memory and then the parameters obtained by best fitting procedures on experimental data are strongly influenced by the prestress on the specimen. As in fact during the relaxation test the imposed history of deformation is not instantaneously applied, since a unit step function may not be realized by the test machine. Aim of this paper, it is shown that, the experimental procedure, and in particular the initial ramp to reach the constant stress (or strain) strongly influences the best fitting procedure and the coefficients of the power-law.

yearjournalcountryeditionlanguage
2013-01-01
http://hdl.handle.net/10447/100189