Study On Optimization Of Composite Tubular Energy Absorption System

A four-phase program to improve the specific energy absorbed by axially crushed composite collapsible tubular energy absorber devices was undertaken. In the first phase, the effects of trigged tube wall on the crushing behaviour were investigated. At this stage, triggered tubes were fabricated an...

Full description

Saved in:

Bibliographic Details
Main Author:	Sultan Aljibori, Hakim S.
Format:	Thesis
Language:	English
Published:	2004
Subjects:	Force and energy - Cmposite materials - Case studies
Online Access:	http://psasir.upm.edu.my/id/eprint/5948/1/FK_2004_55%20IR.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-upm-ir.5948
record_format	uketd_dc
spelling	my-upm-ir.59482022-02-10T02:19:25Z Study On Optimization Of Composite Tubular Energy Absorption System 2004-06 Sultan Aljibori, Hakim S. A four-phase program to improve the specific energy absorbed by axially crushed composite collapsible tubular energy absorber devices was undertaken. In the first phase, the effects of trigged tube wall on the crushing behaviour were investigated. At this stage, triggered tubes were fabricated and crushed. The second phase is aimed at obtaining the best position for the triggered wall. The third phase focuses on the effects of material sizing in order to understand the influence of triggered wall Iength on the responses of composite circular tubes to the axial crushing load. The results from these three phases lead to the fourth phase. The objective of the 4t" phases was to optimise the shape geometry of the cross-section area to further improve tube energy absorption capability. The tubes were manufactured from woven roving glasslepoxy fabric and had the same lay-up providing a common laminate for comparison. The failure modes were observed and the specific sustained crushing loads were determined and compared against non-optimized tubes of the same lay-up. The importance of differentiating between initiation energy and propagation energy is shown, and a new parameter (energy capability index (ECI)) is proposed, as a useful measure for comparing crush behaviour of composite structures. The experimental results demonstrated strong potential benefits of optimizing the material distribution. The sizing and shape optimization of composite collapsible tubes exhibited a pronounced effect on their capability to absorb high specific energy under axial compressive load. For the effect of triggering it was that tubes (TN) observed to experience catastrophic failure mode during the post crush stage also displayed very poor energy absorption. Triggering a part of tube wall was very efficient in improving the energy absorption capacity of circular composite tubes. Accordingly tubes with triggered wall (T-tubes) exhibited highest energy absorption capacity compared with non-triggered tubes. They also experience stable post-crush region of loaddisplacement curves, which leads to high crashworthiness performance. It is also evident from the experimental results that change in the triggered wall aspect ratio significantly affected the energy absorption capability of tube with middle triggered wall (TM-tubes). Distinct differences were observed between the different aspect ratio, where TM tubes (i.e. tubes with triggered wall aspect ratio of 0.28) exhibited the highest energy absorption capacity. Different failure modes were observed for different triggered wall length ratios (Lt,/H). For the core tubes (TMC-), was observed that core presence markedly improved the energy absorption capacity of composite circular tubes. Among TMC- tubes, TMC3 tubes (i.e. tubes with core thickness of 3.35mm) displayed highest energy absorption capacity. Force and energy - Cmposite materials - Case studies 2004-06 Thesis http://psasir.upm.edu.my/id/eprint/5948/ http://psasir.upm.edu.my/id/eprint/5948/1/FK_2004_55%20IR.pdf text en public masters Universiti Putra Malaysia Force and energy - Cmposite materials - Case studies Engineering Ahmad, Elsadig Mahdi
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
advisor	Ahmad, Elsadig Mahdi
topic	Force and energy - Cmposite materials - Case studies
spellingShingle	Force and energy - Cmposite materials - Case studies Sultan Aljibori, Hakim S. Study On Optimization Of Composite Tubular Energy Absorption System
description	A four-phase program to improve the specific energy absorbed by axially crushed composite collapsible tubular energy absorber devices was undertaken. In the first phase, the effects of trigged tube wall on the crushing behaviour were investigated. At this stage, triggered tubes were fabricated and crushed. The second phase is aimed at obtaining the best position for the triggered wall. The third phase focuses on the effects of material sizing in order to understand the influence of triggered wall Iength on the responses of composite circular tubes to the axial crushing load. The results from these three phases lead to the fourth phase. The objective of the 4t" phases was to optimise the shape geometry of the cross-section area to further improve tube energy absorption capability. The tubes were manufactured from woven roving glasslepoxy fabric and had the same lay-up providing a common laminate for comparison. The failure modes were observed and the specific sustained crushing loads were determined and compared against non-optimized tubes of the same lay-up. The importance of differentiating between initiation energy and propagation energy is shown, and a new parameter (energy capability index (ECI)) is proposed, as a useful measure for comparing crush behaviour of composite structures. The experimental results demonstrated strong potential benefits of optimizing the material distribution. The sizing and shape optimization of composite collapsible tubes exhibited a pronounced effect on their capability to absorb high specific energy under axial compressive load. For the effect of triggering it was that tubes (TN) observed to experience catastrophic failure mode during the post crush stage also displayed very poor energy absorption. Triggering a part of tube wall was very efficient in improving the energy absorption capacity of circular composite tubes. Accordingly tubes with triggered wall (T-tubes) exhibited highest energy absorption capacity compared with non-triggered tubes. They also experience stable post-crush region of loaddisplacement curves, which leads to high crashworthiness performance. It is also evident from the experimental results that change in the triggered wall aspect ratio significantly affected the energy absorption capability of tube with middle triggered wall (TM-tubes). Distinct differences were observed between the different aspect ratio, where TM tubes (i.e. tubes with triggered wall aspect ratio of 0.28) exhibited the highest energy absorption capacity. Different failure modes were observed for different triggered wall length ratios (Lt,/H). For the core tubes (TMC-), was observed that core presence markedly improved the energy absorption capacity of composite circular tubes. Among TMC- tubes, TMC3 tubes (i.e. tubes with core thickness of 3.35mm) displayed highest energy absorption capacity.
format	Thesis
qualification_level	Master's degree
author	Sultan Aljibori, Hakim S.
author_facet	Sultan Aljibori, Hakim S.
author_sort	Sultan Aljibori, Hakim S.
title	Study On Optimization Of Composite Tubular Energy Absorption System
title_short	Study On Optimization Of Composite Tubular Energy Absorption System
title_full	Study On Optimization Of Composite Tubular Energy Absorption System
title_fullStr	Study On Optimization Of Composite Tubular Energy Absorption System
title_full_unstemmed	Study On Optimization Of Composite Tubular Energy Absorption System
title_sort	study on optimization of composite tubular energy absorption system
granting_institution	Universiti Putra Malaysia
granting_department	Engineering
publishDate	2004
url	http://psasir.upm.edu.my/id/eprint/5948/1/FK_2004_55%20IR.pdf
_version_	1747810514341199872

Study On Optimization Of Composite Tubular Energy Absorption System

Similar Items