Browsing by Author "Aravas, N."
Now showing items 1-20 of 45
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3-D catalytic regeneration and stress modeling of diesel particulate filters by ABAQUS FEM software
Pontikakis, G.; Stamatelos, A.; Bakasis, K.; Aravas, N. (2002)The design of reliable DPF systems has proved a complex and demanding task that is increasingly being assisted by modeling. 1-D but also 2-D (axisymmetric) modeling has already been applied in design optimization case ... -
A Bayesian methodology for crack identification in structures using strain measurements
Gaitanaros, S.; Karaiskos, G.; Papadimitriou, C.; Aravas, N. (2010)A Bayesian system identification methodology is presented for estimating the crack location, size and orientation in a structure using strain measurements. The Bayesian statistical approach combines information from measured ... -
Constitutive modeling and finite element methods for TRIP steels
Papatriantafillou, I.; Agoras, M.; Aravas, N.; Haidemenopoulos, G. (2006)A constitutive model that describes the mechanical behavior of steels exhibiting "TRansformation Induced Plasticity" (TRIP) during martensitic transformation is presented. Multiphase TRIP steels are considered as composite ... -
Constitutive modeling of porous viscoelastic materials
Xu, F.; Sofronis, P.; Aravas, N.; Meyer, S. (2007)The effect of porosity on the constitutive response of an isotropic linearly viscoelastic solid that obeys a constitutive law of the standard differential form is investigated under small strain deformation conditions. The ... -
Constitutive modeling of solid propellant materials with evolving microstructural damage
Xu, F.; Aravas, N.; Sofronis, P. (2008)Solid propellants are composite materials with complex microstructure. In a generic form, the material consists of polymeric binder, crystal oxidizer (e.g., ammonium perchlorate), and fuel particles (e.g., aluminum). Severe ... -
Constitutive response and damage in solid propellants
Aravas, N.; Xu, F.; Sofronis, P.; Namazifard, A.; Fiedler, R. (2005)Solid propellants are composite materials with complex microstructure. In a generic form, the material consists of polymeric binder, ceramic oxidizer, and fuel particles (e.g. aluminum). Damage induced by severe stress and ... -
Detailed simulations of propellant slumping in the titanIV SRMU PQM-1
Fiedler, R.; Namazifard, A.; Campbell, M.; Xu, F.; Aravas, N.; Sofronis, P. (2006)We utilize our tightly-coupled fluid/structure/combustion solid propellent rocket simulation package ("Rocstar") to study the unexpectedly large deformation of propellant at the center joint slot in a prequalification ... -
Evaluation of creep damage of INCOLOY 800HT pigtails in a refinery steam reformer unit
Spyrou, L. A.; Sarafoglou, P. I.; Aravas, N.; Haidemenopoulos, G. N. (2014)Pigtail tubes constitute a critical component of the outlet system of steam reformer units for hydrogen production in refineries. Creep failure of pigtails is a common cause of downtime and potential risk to plant personnel. ... -
Finite element implementation of gradient plasticity models - Part I: Gradient-dependent yield functions
Ramaswamy, S.; Aravas, N. (1998)Theories with intrinsic or material length scales find applications in the modeling of size-dependent phenomena such as, for example, the localization of plastic flow into shear bands. In gradient-type plasticity theories, ... -
Finite element implementation of gradient plasticity models - Part II: Gradient-dependent evolution equations
Ramaswamy, S.; Aravas, N. (1998)The variational formulation and finite element implementation of a class of plasticity models with gradient-dependent yield functions is covered in detail in Part I. In this sequel, attention is focussed upon the finite ... -
Finite element implementation of gradient plasticity models part I: Gradient-dependent yield functions
Ramaswamy, S.; Aravas, N. (1998)Theories with intrinsic or material length scales find applications in the modeling of size-dependent phenomena such as, for example, the localization of plastic flow into shear bands. In gradient-type plasticity theories, ... -
Finite element implementation of gradient plasticity models Part II: Gradient-dependent evolution equations
Ramaswamy, S.; Aravas, N. (1998)The variational formulation and finite element implementation of a class of plasticity models with gradient-dependent yield functions is covered in detail in Part I. In this sequel, attention is focussed upon the finite ... -
A finite element model of the Ilizarov fixator system
Toumanidou, Th; Spyrou, L. A.; Aravas, N. (2011)Mechanical characteristics of orthopaedic fixators, such as stiffness and stability, directly influence the mechanobiological environment in which the bone is healed. A comprehensive understanding of the sensitivity of the ... -
Finite element modeling of porous solid propellants
Xu, F.; Sofronis, P.; Aravas, N.; Namazifard, A.; Fiedler, R. (2005)The effect of porosity on the constitutive response of a linearly viscoelastic solid that obeys a constitutive law of the standard differential form is investigated under small strain deformation conditions. It is demonstrated ... -
Finite element modeling of trip steels
Papatriantafillou, I.; Aravas, N. (2004)In this paper, a constitutive model that describes the mechanical behavior of steels exhibiting the "Transformation Induced Plasticity" (TRIP) phenomenon during martensitic transformation is presented. Multiphase TRIP ... -
Finite element modelling of TRIP steels
Papatriantafillou, I.; Aravas, N.; Haidemenopoulos, G. N. (2004)A constitutive model that describes the mechanical behaviour of steels exhibiting "Transformation Induced Plasticity" (TRIP) during martensitic transformation is presented. Multiphase TRIP steels are considered as composite ... -
Hydrogen induced shear localization of the plastic flow in metals and alloys
Sofronis, P.; Liang, Y.; Aravas, N. (2001)Hydrogen enhanced localized plasticity (HELP) is a viable mechanism for hydrogen embrittlement supported by experimental observations. According to the HELP mechanism, hydrogen induced premature failures result from hydrogen ... -
Kinetics of strain-induced transformation of dispersed austenite in low-alloy TRIP steels
Haidemenopoulos, G. N.; Aravas, N.; Bellas, I. (2014)A model describing the kinetics of the evolution of martensite volume fraction during the strain-induced transformation of dispersed austenite in low-alloy TRIP steels has been developed. The model is based on the modification ... -
A Linear Complementarity formulation of rate-independent finite-strain elastoplasticity. Part I: Algorithm for numerical integration
Bassi, A.; Aravas, N.; Genna, F. (2012)A methodology for the numerical integration of rate-independent, elastic-plastic finite-strain models is developed. The methodology is based on the idea of local linearization of the yield surface that was proposed in Maier ... -
A Linear Complementarity formulation of rate-independent finite-strain elastoplasticity. Part II: Calculation of bifurcation and limit points
Bassi, A.; Aravas, N.; Genna, F. (2012)A methodology for the numerical solution of discretized boundary value problems that involve rate-independent, elastic-plastic finite-strain models is developed. The formulation is given in terms of a structural Linear ...