Structural Dynamic Modelling of a Multi-Storey Shear Frame using Mass and Stiffness Addition

Designers of systems involved in high-speed operation and users of lightweight structures have realised that measurement of stress/strain properties are not sufficient and that dynamic measurement / analysis are necessary for a comprehensive understanding of the characteristics. The shear frame structure was modelled using solid elements (ANSYS solid 187) and the discrepancy between the experimental and initial numerical results were very high. The three experimental modes were observe and the suspected areas of local stiffness were noted; these being the areas of connection between the floor plates and vertical pillars and ANSYS shell 181 was used to adjust the stiffness locally. Also with appropriate engineering judgements, omitted masses compared with the physical structure were added locally using ANSYS mass 21 element type. In addition, the finite element model boundary conditions were carefully manipulated to predict the experiment condition.  This technique of updating proved to be very successful as the mix-match between the experimental and finite element results were reduced

Water Absorption And Effect Of Temperature On The Characteristics Of Flax/Hemp Reinforced Composites

Composite are now accepted in various structural application; but the current emphasis has shifted towards environmental issues, which gives natural fibres the advantage as they are eco-friendly and biodegradable. This study involved the water absorption behaviour of flax/hemp combined natural fibres and the bending characteristics of flax/hemp polyester composites treated at various temperatures. The stiffness of the composite was observed to reduce at 110°C. The moisture absorption profile did rise to a variable plateau

The Effect of Ply Orientation on the Vibration Characteristics of ‘T’ Stiffen Composite Panel: A Finite Element Study

Aircraft producers have extensively adopted the use of T-shaped stiffened fibre reinforced composite panels in the thin walled structures such as the fuselage and wings. The composite materials present the advantage of high specific strength and stiffness ratios, coupled with weight reduction compare to traditional materials. This report presents a numerical study about the free-free vibration analysis of T-stiffened carbon fibre reinforced epoxy composite panels with surface and identical ply orientations of 00, 150, 300, 450, 600, 750 and 900 using ANSYS 17 finite element code and the results presented herein. The fundamental frequencies increase to a peak and then decrease taking the form a half sine curve. The dynamic analysis was realized using the Lanczos tool to extract the mode shapes and natural frequencies

The Effect of Ply Orientation on the Vibration Characteristics of ‘T’ Stiffen Composites Panel: A Finite Element Study

This is an open access article, distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/Aircraft producers have extensively adopted the use of T-shaped stiffened fibre reinforced composite panels in the thin walled structures such as the fuselage and wings. The composite materials present the advantage of high specific strength and stiffness ratios, coupled with weight reduction compare to traditional materials. This report presents a numerical study about the free-free vibration analysis of T-stiffened carbon fibre reinforced epoxy composite panels with surface and identical ply orientations of 0°, 15°, 30°, 45°, 60°, 75° and 90° using ANSYS 17 finite element code. These changes has effect on the element stiffness matrix and hence the dynamic characteristics of the panels. The fundamental frequencies increase to a peak and then decrease taking the form a half sine curve. The dynamic analysis was realized using the Lanczos tool to extract the mode shapes and natural frequencies.Peer reviewedFinal Published versio

Structural Dynamic Modelling of a Multi-Storey Shear Frame using Mass and Stiffness Addition

© 2020 The Author. This is an open access article licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/).Designers of systems involved in high-speed operation and users of lightweight structures have realised that measurement of stress/strain properties are not sufficient and that dynamic measurement / analysis are necessary for a comprehensive understanding of the characteristics. The shear frame structure was modelled using solid elements (ANSYS solid 187) and the discrepancy between the experimental and initial numerical results were very high. The three experimental modes were observe and the suspected areas of local stiffness were noted; these being the areas of connection between the floor plates and vertical pillars and ANSYS shell 181 was used to adjust the stiffness locally. Also with appropriate engineering judgements, omitted masses compared with the physical structure were added locally using ANSYS mass 21 element type. In addition, the finite element model boundary conditions were carefully manipulated to predict the experiment condition. This technique of updating proved to be very successful as the mix-match between the experimental and finite element results were reduced.Peer reviewedFinal Published versio

Mechanical testing of natural fibre reinforced polyester resin composites and Mode 1 fracture toughness testing of resin blocks

Recent European Parliament directive requires companies to achieve materials recycling greater than 80% in particular in the automotive sector [1]. The research on natural fibre based composite materials fits well into this ecological image. The advantages of natural fibres over synthetic materials include, low density, relative cheapness, availability and biodegradability. In this paper we explore the fabrication and mechanical testing of natural fibre composites and this is part of an on going study at Strathclyde University and describes the fabrication of composites using natural fibre and styrene polyester resin. The properties of the synthetic resin can be varied by changing the catalysts concentration and flexural (three point bending) and single-edged notched bending (SENB) properties are reported at different concentrations of the catalyst

The effect of alkalisation on the mechanical properties of natural fibres

A study on the effect of alkalisaton using 3% NaOH solution was carried out on Flax, Kenaf, Abaca and Sisal to observe the impact that the common pre-treatment process has on fibre mechanical properties. The result of the investigation indicated that over-treatment of natural fibres using NaOH could have a negative effect on the base fibre properties. It is concluded that a treatment time of less than 10 minutes is sufficient to remove hemicelluloses and to give the optimum effect

Vacuum infusion of natural fibre composites for structural applications

Numerous methods of manufacturing natural fibre composites have been reported in the literature, including compression moudling, often in conjunction with a hot press. Other forms of composite manufacture include 'Vacuum Assisted Resin Transfer Moulding' (VATRM) and the 'Seemann Composite Resin Infusion Moulding Process' (SCRIMP). These methods have been reported to produce natural fibre composies with reasonable mechanical properties [1-2]. In this paper, a vacuum infusion rig is described that has been developed to produce consistent quality composite plates for studies into optimising natural fibre composites. The process aims to harness the benefits of vacuum infusion and compression moulding, where vacuum infusion encourages the removal of trapped air in the system and hence avoid reduction, and additional compression moulding can help to achieve high volume fractions that are otherwise difficult in other processes

Tensile testing of cellulose based natural fibers for structural composite applications

A series of tensile tests were conducted on a Lloyd LRX tensile testing machine for numerous natural fibers deemed potential candidates for development in composite applications. The tensile tests were conducted on the fibers jute, kenaf, flax, abaca, sisal, hemp, and coir for samples exposed to moisture conditions of (1) room temperature and humidity, (2) 65% moisture content, (3) 90% moisture content, and (4) soaked fiber. These seven fibers were then tested for the four conditions and the mechanical properties of tensile strength, tensile strain to failure, and Young's modulus were calculated for the results. These results were then compared and verified with those from the literature, with some of the fibers showing distinctly promising potential. Additionally, a study on the effect of alkalization using 3% NaOH solution was carried out on flax, kenaf, abaca, and sisal to observe impact that this common fiber pre-treatment process has on fiber mechanical properties. The result of the investigation indicated that over treatment of natural fibers using NaOH could have a negative effect on the base fiber properties. It is consequently apparent that a treatment time of less than 10 min is sufficient to remove hemicelluloses and to give the optimum effect

Proceedings of Abstracts Engineering and Computer Science Research Conference 2019

© 2019 The Author(s). This is an open-access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For further details please see https://creativecommons.org/licenses/by/4.0/. Note: Keynote: Fluorescence visualisation to evaluate effectiveness of personal protective equipment for infection control is © 2019 Crown copyright and so is licensed under the Open Government Licence v3.0. Under this licence users are permitted to copy, publish, distribute and transmit the Information; adapt the Information; exploit the Information commercially and non-commercially for example, by combining it with other Information, or by including it in your own product or application. Where you do any of the above you must acknowledge the source of the Information in your product or application by including or linking to any attribution statement specified by the Information Provider(s) and, where possible, provide a link to this licence: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/This book is the record of abstracts submitted and accepted for presentation at the Inaugural Engineering and Computer Science Research Conference held 17th April 2019 at the University of Hertfordshire, Hatfield, UK. This conference is a local event aiming at bringing together the research students, staff and eminent external guests to celebrate Engineering and Computer Science Research at the University of Hertfordshire. The ECS Research Conference aims to showcase the broad landscape of research taking place in the School of Engineering and Computer Science. The 2019 conference was articulated around three topical cross-disciplinary themes: Make and Preserve the Future; Connect the People and Cities; and Protect and Care