No Cover Image

E-Thesis 281 views 554 downloads

Nonlinear finite element simulation of non-local tension softening for high strength steel material. / F. M Tong

Swansea University Author: F. M Tong

Abstract

The capability of current finite element softwares in simulating the stress-strain relation beyond the elastic-plastic region has been limited by the inability for non- positivity in the computational finite elements' stiffness matrixes. Although analysis up to the peak stress has been proved a...

Full description

Published: 2008
Institution: Swansea University
Degree level: Master of Philosophy
Degree name: M.Phil
URI: https://cronfa.swan.ac.uk/Record/cronfa42368
first_indexed 2018-08-02T18:54:32Z
last_indexed 2019-10-21T16:47:41Z
id cronfa42368
recordtype RisThesis
fullrecord <?xml version="1.0"?><rfc1807><datestamp>2018-08-16T14:39:02.9105634</datestamp><bib-version>v2</bib-version><id>42368</id><entry>2018-08-02</entry><title>Nonlinear finite element simulation of non-local tension softening for high strength steel material.</title><swanseaauthors><author><sid>3c274575cb68b7e9f16f94e7e82d80c9</sid><ORCID>NULL</ORCID><firstname>F. M</firstname><surname>Tong</surname><name>F. M Tong</name><active>true</active><ethesisStudent>true</ethesisStudent></author></swanseaauthors><date>2018-08-02</date><abstract>The capability of current finite element softwares in simulating the stress-strain relation beyond the elastic-plastic region has been limited by the inability for non- positivity in the computational finite elements' stiffness matrixes. Although analysis up to the peak stress has been proved adequate for analysis and design, it provides no indication of the possible failure predicament that is to follow. Therefore an attempt was made to develop a modelling technique capable of capturing the complete stress-deformation response in an analysis beyond the limit point. This proposed model characterizes a cyclic loading and unloading procedure, as observed in a typical laboratory uniaxial cyclic test, along with a series of material properties updates. The Voce equation and a polynomial function were proposed to define the monotonic elastoplastic hardening and softening behaviour respectively. A modified form of the Voce equation was used to capture the reloading response in the softening region. To accommodate the reduced load capacity of the material at each subsequent softening point, an optimization macro was written to control this optimum load at which the material could withstand. This preliminary study has ignored geometrical effect and is thus incapable of capturing the localized necking phenomenon that accompanies many ductile materials. The current softening model is sufficient if a global measure is considered. Several validation cases were performed to investigate the feasibility of the modelling technique and the results have been proved satisfactory. The ANSYS finite element software is used as the platform at which the modelling technique operates.</abstract><type>E-Thesis</type><journal/><journalNumber></journalNumber><paginationStart/><paginationEnd/><publisher/><placeOfPublication/><isbnPrint/><issnPrint/><issnElectronic/><keywords>Materials science.</keywords><publishedDay>31</publishedDay><publishedMonth>12</publishedMonth><publishedYear>2008</publishedYear><publishedDate>2008-12-31</publishedDate><doi/><url/><notes/><college>COLLEGE NANME</college><department>Engineering</department><CollegeCode>COLLEGE CODE</CollegeCode><institution>Swansea University</institution><degreelevel>Master of Philosophy</degreelevel><degreename>M.Phil</degreename><apcterm/><lastEdited>2018-08-16T14:39:02.9105634</lastEdited><Created>2018-08-02T16:24:28.9945936</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Engineering and Applied Sciences - Uncategorised</level></path><authors><author><firstname>F. M</firstname><surname>Tong</surname><orcid>NULL</orcid><order>1</order></author></authors><documents><document><filename>0042368-02082018162448.pdf</filename><originalFilename>10798076.pdf</originalFilename><uploaded>2018-08-02T16:24:48.9330000</uploaded><type>Output</type><contentLength>7228101</contentLength><contentType>application/pdf</contentType><version>E-Thesis</version><cronfaStatus>true</cronfaStatus><embargoDate>2018-08-02T16:24:48.9330000</embargoDate><copyrightCorrect>false</copyrightCorrect></document></documents><OutputDurs/></rfc1807>
spelling 2018-08-16T14:39:02.9105634 v2 42368 2018-08-02 Nonlinear finite element simulation of non-local tension softening for high strength steel material. 3c274575cb68b7e9f16f94e7e82d80c9 NULL F. M Tong F. M Tong true true 2018-08-02 The capability of current finite element softwares in simulating the stress-strain relation beyond the elastic-plastic region has been limited by the inability for non- positivity in the computational finite elements' stiffness matrixes. Although analysis up to the peak stress has been proved adequate for analysis and design, it provides no indication of the possible failure predicament that is to follow. Therefore an attempt was made to develop a modelling technique capable of capturing the complete stress-deformation response in an analysis beyond the limit point. This proposed model characterizes a cyclic loading and unloading procedure, as observed in a typical laboratory uniaxial cyclic test, along with a series of material properties updates. The Voce equation and a polynomial function were proposed to define the monotonic elastoplastic hardening and softening behaviour respectively. A modified form of the Voce equation was used to capture the reloading response in the softening region. To accommodate the reduced load capacity of the material at each subsequent softening point, an optimization macro was written to control this optimum load at which the material could withstand. This preliminary study has ignored geometrical effect and is thus incapable of capturing the localized necking phenomenon that accompanies many ductile materials. The current softening model is sufficient if a global measure is considered. Several validation cases were performed to investigate the feasibility of the modelling technique and the results have been proved satisfactory. The ANSYS finite element software is used as the platform at which the modelling technique operates. E-Thesis Materials science. 31 12 2008 2008-12-31 COLLEGE NANME Engineering COLLEGE CODE Swansea University Master of Philosophy M.Phil 2018-08-16T14:39:02.9105634 2018-08-02T16:24:28.9945936 Faculty of Science and Engineering School of Engineering and Applied Sciences - Uncategorised F. M Tong NULL 1 0042368-02082018162448.pdf 10798076.pdf 2018-08-02T16:24:48.9330000 Output 7228101 application/pdf E-Thesis true 2018-08-02T16:24:48.9330000 false
title Nonlinear finite element simulation of non-local tension softening for high strength steel material.
spellingShingle Nonlinear finite element simulation of non-local tension softening for high strength steel material.
F. M Tong
title_short Nonlinear finite element simulation of non-local tension softening for high strength steel material.
title_full Nonlinear finite element simulation of non-local tension softening for high strength steel material.
title_fullStr Nonlinear finite element simulation of non-local tension softening for high strength steel material.
title_full_unstemmed Nonlinear finite element simulation of non-local tension softening for high strength steel material.
title_sort Nonlinear finite element simulation of non-local tension softening for high strength steel material.
author_id_str_mv 3c274575cb68b7e9f16f94e7e82d80c9
author_id_fullname_str_mv 3c274575cb68b7e9f16f94e7e82d80c9_***_F. M Tong
author F. M Tong
author2 F. M Tong
format E-Thesis
publishDate 2008
institution Swansea University
college_str Faculty of Science and Engineering
hierarchytype
hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Uncategorised{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Uncategorised
document_store_str 1
active_str 0
description The capability of current finite element softwares in simulating the stress-strain relation beyond the elastic-plastic region has been limited by the inability for non- positivity in the computational finite elements' stiffness matrixes. Although analysis up to the peak stress has been proved adequate for analysis and design, it provides no indication of the possible failure predicament that is to follow. Therefore an attempt was made to develop a modelling technique capable of capturing the complete stress-deformation response in an analysis beyond the limit point. This proposed model characterizes a cyclic loading and unloading procedure, as observed in a typical laboratory uniaxial cyclic test, along with a series of material properties updates. The Voce equation and a polynomial function were proposed to define the monotonic elastoplastic hardening and softening behaviour respectively. A modified form of the Voce equation was used to capture the reloading response in the softening region. To accommodate the reduced load capacity of the material at each subsequent softening point, an optimization macro was written to control this optimum load at which the material could withstand. This preliminary study has ignored geometrical effect and is thus incapable of capturing the localized necking phenomenon that accompanies many ductile materials. The current softening model is sufficient if a global measure is considered. Several validation cases were performed to investigate the feasibility of the modelling technique and the results have been proved satisfactory. The ANSYS finite element software is used as the platform at which the modelling technique operates.
published_date 2008-12-31T04:23:29Z
_version_ 1851365586330714112
score 11.089572

Similar Items