Accelerated Fatigue Properties of Unidirectional Composite Materials

博士 === 雲林科技大學 === 工程科技研究所博士班 === 96 === It has been confirmed that polymer matrix composites possess viscoelastic behavior. This means that one could accelerate the fatigue testing by changing the stress amplitude, frequency or temperature. This study is to invest the accelerated fatigue properties,...

Full description

Bibliographic Details
Main Authors: Hsing-sung Chen, 陳興松
Other Authors: Shun-Fa Hwang
Format: Others
Language:en_US
Published: 2008
Online Access:http://ndltd.ncl.edu.tw/handle/03417609577210288625
id ndltd-TW-096YUNT5028004
record_format oai_dc
spelling ndltd-TW-096YUNT50280042015-10-13T11:20:18Z http://ndltd.ncl.edu.tw/handle/03417609577210288625 Accelerated Fatigue Properties of Unidirectional Composite Materials 複合材料加速疲勞特性之研究 Hsing-sung Chen 陳興松 博士 雲林科技大學 工程科技研究所博士班 96 It has been confirmed that polymer matrix composites possess viscoelastic behavior. This means that one could accelerate the fatigue testing by changing the stress amplitude, frequency or temperature. This study is to invest the accelerated fatigue properties, which resulted from the viscoelastic behavior, of carbon/epoxy and glass/epoxy composites and to predict their fatigue life. For this purpose, a series of fatigue tests of unidirectional specimens are conducted at room temperature under different stress ratios and stress frequencies. A group of sigmoid S-N curves which are suitable for the whole fatigue life and the corresponding parameters are developed for different cyclic loading conditions. A transformation method, which can transform a reference S-N curve to the corresponding S-N curve of the assigned fatigue conditions, is established by the parameters. And this S-N curve can be utilized to predict the fatigue life of the composite at the assigned stress ratio or stress frequency. The comparison between the linear and sigmoid S-N curves is also carried out to show the advantages of the latter model in the whole fatigue life. Following, a nonlinear damage model, which was based on a physical phenomenon of damage growth, for the composites that includes the nonlinear effects of stress ratio and loading frequency on the damage processes was developed. A damage index was defined and the corresponding parameters were decided. A series of two-stress level fatigue tests were conducted to confirm the validity of this model. The results reveal that the model of this study is benefit to assess the fatigue damage caused by different stress ratios and frequencies. Shun-Fa Hwang 黃順發 2008 學位論文 ; thesis 121 en_US
collection NDLTD
language en_US
format Others
sources NDLTD
description 博士 === 雲林科技大學 === 工程科技研究所博士班 === 96 === It has been confirmed that polymer matrix composites possess viscoelastic behavior. This means that one could accelerate the fatigue testing by changing the stress amplitude, frequency or temperature. This study is to invest the accelerated fatigue properties, which resulted from the viscoelastic behavior, of carbon/epoxy and glass/epoxy composites and to predict their fatigue life. For this purpose, a series of fatigue tests of unidirectional specimens are conducted at room temperature under different stress ratios and stress frequencies. A group of sigmoid S-N curves which are suitable for the whole fatigue life and the corresponding parameters are developed for different cyclic loading conditions. A transformation method, which can transform a reference S-N curve to the corresponding S-N curve of the assigned fatigue conditions, is established by the parameters. And this S-N curve can be utilized to predict the fatigue life of the composite at the assigned stress ratio or stress frequency. The comparison between the linear and sigmoid S-N curves is also carried out to show the advantages of the latter model in the whole fatigue life. Following, a nonlinear damage model, which was based on a physical phenomenon of damage growth, for the composites that includes the nonlinear effects of stress ratio and loading frequency on the damage processes was developed. A damage index was defined and the corresponding parameters were decided. A series of two-stress level fatigue tests were conducted to confirm the validity of this model. The results reveal that the model of this study is benefit to assess the fatigue damage caused by different stress ratios and frequencies.
author2 Shun-Fa Hwang
author_facet Shun-Fa Hwang
Hsing-sung Chen
陳興松
author Hsing-sung Chen
陳興松
spellingShingle Hsing-sung Chen
陳興松
Accelerated Fatigue Properties of Unidirectional Composite Materials
author_sort Hsing-sung Chen
title Accelerated Fatigue Properties of Unidirectional Composite Materials
title_short Accelerated Fatigue Properties of Unidirectional Composite Materials
title_full Accelerated Fatigue Properties of Unidirectional Composite Materials
title_fullStr Accelerated Fatigue Properties of Unidirectional Composite Materials
title_full_unstemmed Accelerated Fatigue Properties of Unidirectional Composite Materials
title_sort accelerated fatigue properties of unidirectional composite materials
publishDate 2008
url http://ndltd.ncl.edu.tw/handle/03417609577210288625
work_keys_str_mv AT hsingsungchen acceleratedfatiguepropertiesofunidirectionalcompositematerials
AT chénxìngsōng acceleratedfatiguepropertiesofunidirectionalcompositematerials
AT hsingsungchen fùhécáiliàojiāsùpíláotèxìngzhīyánjiū
AT chénxìngsōng fùhécáiliàojiāsùpíláotèxìngzhīyánjiū
_version_ 1716841379351494656