Experimental And Multiscale Finite Element Analysis Of Pultruded Kenaf Composites Under Compressive Impact Load

Kenaf natural composites are recognized for ecological qualities such as biodegradability, lightweight and renewable. Due to global climate change and greenhouse gas emissions, it has pushed the engagement of kenaf natural composite in load-bearing primary structures. Hence, detailed analysis of str...

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Main Author:	Seman, Sareh Aiman Hilmi Abu
Format:	Thesis
Language:	English
Published:	2019
Subjects:	T Technology
Online Access:	http://eprints.usm.my/51231/1/Experimental%20And%20Multiscale%20Finite%20Element%20Analysis%20Of%20Pultruded%20Kenaf%20Composites%20Under%20Compressive%20Impact%20Load.pdf
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spelling	my-usm-ep.512312022-01-19T07:50:38Z Experimental And Multiscale Finite Element Analysis Of Pultruded Kenaf Composites Under Compressive Impact Load 2019-07-01 Seman, Sareh Aiman Hilmi Abu T Technology T351-385 Mechanical drawing. Engineering graphics Kenaf natural composites are recognized for ecological qualities such as biodegradability, lightweight and renewable. Due to global climate change and greenhouse gas emissions, it has pushed the engagement of kenaf natural composite in load-bearing primary structures. Hence, detailed analysis of structural responses and prediction of damage are needed for structural integrity valuation. In this research project, an extensive experimental and microscopic study were conducted to characterize the mechanical and damage behavior of pultruded kenaf composites at various strain rates using modified compression split Hopkinson pressure bar (SHPB) and universal testing machine (UTM) techniques meanwhile scanning electron microscope (SEM) was used to capture surface morphology of damaged samples. A multi-scale modelling approach which consist of micro, meso and macro-scale models are developed to provide a numerical estimate of the response and failure modes observed in unidirectional kenaf fiber reinforced composites under compressive high strain rate loading. In these models, Hashin-based criteria through a user-defined material subroutine (VUMAT) was used for damage initiation while continuum damage mechanics (CDM) approach was employed to predict the damage progression in composite. Initiation and progression of fiber-matrix debonding was studied by employing cohesive zone elements. The experimental results indicate that the failure stress, failure strain and compressive modulus show different strain rate sensitivity with increasing strain rate. Post-test scanning electron microscopy reveals that the dominant failure modes and mechanisms in the kenaf composites under uniaxial compression are different as the loading condition changes from quasi-static to dynamic. Good correlation with average error of <2% is obtained between the measured experimental and numerically obtained stress-strain curves as well as failure modes which are responsible for damage development and growth. The effect of fibers misalignment and arrangement are also analyzed numerically by considering the overall predicted properties as well as damage areas and pattern which varies due to shear instability and relative distance between fibers. The promising results obtained with these models can be useful in the development of predictive procedures to provide new high strain rate application especially in automotive and aerospace industries for kenaf composite materials. 2019-07 Thesis http://eprints.usm.my/51231/ http://eprints.usm.my/51231/1/Experimental%20And%20Multiscale%20Finite%20Element%20Analysis%20Of%20Pultruded%20Kenaf%20Composites%20Under%20Compressive%20Impact%20Load.pdf application/pdf en public phd doctoral Universiti Sains Malaysia Pusat Pengajian Kejuruteraan Mekanik
institution	Universiti Sains Malaysia
collection	USM Institutional Repository
language	English
topic	T Technology T Technology
spellingShingle	T Technology T Technology Seman, Sareh Aiman Hilmi Abu Experimental And Multiscale Finite Element Analysis Of Pultruded Kenaf Composites Under Compressive Impact Load
description	Kenaf natural composites are recognized for ecological qualities such as biodegradability, lightweight and renewable. Due to global climate change and greenhouse gas emissions, it has pushed the engagement of kenaf natural composite in load-bearing primary structures. Hence, detailed analysis of structural responses and prediction of damage are needed for structural integrity valuation. In this research project, an extensive experimental and microscopic study were conducted to characterize the mechanical and damage behavior of pultruded kenaf composites at various strain rates using modified compression split Hopkinson pressure bar (SHPB) and universal testing machine (UTM) techniques meanwhile scanning electron microscope (SEM) was used to capture surface morphology of damaged samples. A multi-scale modelling approach which consist of micro, meso and macro-scale models are developed to provide a numerical estimate of the response and failure modes observed in unidirectional kenaf fiber reinforced composites under compressive high strain rate loading. In these models, Hashin-based criteria through a user-defined material subroutine (VUMAT) was used for damage initiation while continuum damage mechanics (CDM) approach was employed to predict the damage progression in composite. Initiation and progression of fiber-matrix debonding was studied by employing cohesive zone elements. The experimental results indicate that the failure stress, failure strain and compressive modulus show different strain rate sensitivity with increasing strain rate. Post-test scanning electron microscopy reveals that the dominant failure modes and mechanisms in the kenaf composites under uniaxial compression are different as the loading condition changes from quasi-static to dynamic. Good correlation with average error of <2% is obtained between the measured experimental and numerically obtained stress-strain curves as well as failure modes which are responsible for damage development and growth. The effect of fibers misalignment and arrangement are also analyzed numerically by considering the overall predicted properties as well as damage areas and pattern which varies due to shear instability and relative distance between fibers. The promising results obtained with these models can be useful in the development of predictive procedures to provide new high strain rate application especially in automotive and aerospace industries for kenaf composite materials.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Seman, Sareh Aiman Hilmi Abu
author_facet	Seman, Sareh Aiman Hilmi Abu
author_sort	Seman, Sareh Aiman Hilmi Abu
title	Experimental And Multiscale Finite Element Analysis Of Pultruded Kenaf Composites Under Compressive Impact Load
title_short	Experimental And Multiscale Finite Element Analysis Of Pultruded Kenaf Composites Under Compressive Impact Load
title_full	Experimental And Multiscale Finite Element Analysis Of Pultruded Kenaf Composites Under Compressive Impact Load
title_fullStr	Experimental And Multiscale Finite Element Analysis Of Pultruded Kenaf Composites Under Compressive Impact Load
title_full_unstemmed	Experimental And Multiscale Finite Element Analysis Of Pultruded Kenaf Composites Under Compressive Impact Load
title_sort	experimental and multiscale finite element analysis of pultruded kenaf composites under compressive impact load
granting_institution	Universiti Sains Malaysia
granting_department	Pusat Pengajian Kejuruteraan Mekanik
publishDate	2019
url	http://eprints.usm.my/51231/1/Experimental%20And%20Multiscale%20Finite%20Element%20Analysis%20Of%20Pultruded%20Kenaf%20Composites%20Under%20Compressive%20Impact%20Load.pdf
_version_	1747822065293983744

Experimental And Multiscale Finite Element Analysis Of Pultruded Kenaf Composites Under Compressive Impact Load

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