An Inverse Computational Approach for the Identification of the Parameters of the Constitutive Model for Damaged Ceramics Subjected to Impact Loading

Persistent Link:
http://hdl.handle.net/10150/193721
Title:
An Inverse Computational Approach for the Identification of the Parameters of the Constitutive Model for Damaged Ceramics Subjected to Impact Loading
Author:
Krashanitsa, Roman Yurievich
Issue Date:
2005
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
In the present study, a computational method was developed, validated and applied for the determination of parameters of a constitutive model for a ceramic material. An optimization algorithm, based on a direct search method, was applied to the determination of the load-displacement response of the specimen, and for the identification of the parameters of the constitutive model.A one-dimensional nonlinear initial-boundary value problem of wave propagation in a composite bar made of dissimilar materials was formulated and solved numerically. Convergence of the numerical scheme was studied, and range of convergence was established. Numerical scheme was validated for a number of benchmark problems with known analytical solutions, and for the problems solved using finite element method. Investigation of the accuracy of the displacement and strain responses was conducted; known limitations of the Kolsky's method for split Hopkinson pressure bar were revealed. For numerical examples considered in the present study, comparison of performance of the optimized finite-difference solver and of the finite element code LS-DYNA showed that the finite-difference code is about 10 times faster.Developed method and solutions were applied for the identification of the parameters of the Johnson-Holmquist constitutive model for five sets of experimental data for aluminum oxide AD995. Results of analysis revealed significant sensitivity of stress response to variation of fractured strength model parameters and damage model parameters.For the determined values of parameters, detailed parametric study of stress field, damage accumulation, and velocity field, was conducted with the help of the finite element method.It was found that the accuracy of the simulation using the JH-2 constitutive model changes with the rate of damage accumulation in the ceramic material.The damage patterns and history of damage development, obtained numerically, agreed qualitatively with the fracture history and its patterns, observed in the recovered Macor ceramics available in the literature.A method for image analysis of the photographic images of the lateral sides of the recovered specimen was proposed. It was used to quantify density of the damage in the specimen and to establish a better integral approach to predict amount of damage inside the specimen.
Type:
text; Electronic Dissertation
Keywords:
Identification; ceramics; impact loading; constitutive model; FEM; finite difference; numerical method
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Mechanical Engineering; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Shkarayev, Sergey V.
Committee Chair:
Shkarayev, Sergey V.

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleAn Inverse Computational Approach for the Identification of the Parameters of the Constitutive Model for Damaged Ceramics Subjected to Impact Loadingen_US
dc.creatorKrashanitsa, Roman Yurievichen_US
dc.contributor.authorKrashanitsa, Roman Yurievichen_US
dc.date.issued2005en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractIn the present study, a computational method was developed, validated and applied for the determination of parameters of a constitutive model for a ceramic material. An optimization algorithm, based on a direct search method, was applied to the determination of the load-displacement response of the specimen, and for the identification of the parameters of the constitutive model.A one-dimensional nonlinear initial-boundary value problem of wave propagation in a composite bar made of dissimilar materials was formulated and solved numerically. Convergence of the numerical scheme was studied, and range of convergence was established. Numerical scheme was validated for a number of benchmark problems with known analytical solutions, and for the problems solved using finite element method. Investigation of the accuracy of the displacement and strain responses was conducted; known limitations of the Kolsky's method for split Hopkinson pressure bar were revealed. For numerical examples considered in the present study, comparison of performance of the optimized finite-difference solver and of the finite element code LS-DYNA showed that the finite-difference code is about 10 times faster.Developed method and solutions were applied for the identification of the parameters of the Johnson-Holmquist constitutive model for five sets of experimental data for aluminum oxide AD995. Results of analysis revealed significant sensitivity of stress response to variation of fractured strength model parameters and damage model parameters.For the determined values of parameters, detailed parametric study of stress field, damage accumulation, and velocity field, was conducted with the help of the finite element method.It was found that the accuracy of the simulation using the JH-2 constitutive model changes with the rate of damage accumulation in the ceramic material.The damage patterns and history of damage development, obtained numerically, agreed qualitatively with the fracture history and its patterns, observed in the recovered Macor ceramics available in the literature.A method for image analysis of the photographic images of the lateral sides of the recovered specimen was proposed. It was used to quantify density of the damage in the specimen and to establish a better integral approach to predict amount of damage inside the specimen.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectIdentificationen_US
dc.subjectceramicsen_US
dc.subjectimpact loadingen_US
dc.subjectconstitutive modelen_US
dc.subjectFEMen_US
dc.subjectfinite differenceen_US
dc.subjectnumerical methoden_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineMechanical Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorShkarayev, Sergey V.en_US
dc.contributor.chairShkarayev, Sergey V.en_US
dc.contributor.committeememberTribikram, Kunduen_US
dc.contributor.committeememberChen, Weinong Wayneen_US
dc.contributor.committeememberIndik, Roberten_US
dc.identifier.proquest1390en_US
dc.identifier.oclc137355413en_US
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