BUCKLING AND POST-BUCKLING OF ISOTROPIC AND COMPOSITE STIFFENED PANELS: A REVIEW ON OPTIMISATION (2000-2015)

2021 ◽  
Vol 158 (A3) ◽  
Author(s):  
X-Y Ni ◽  
B G Prusty ◽  
A K Hellier
Keyword(s):  
Critical Discussion ◽  
Loading Capacity ◽  
Light Weight ◽  
Structural Elements ◽  
Engineering Structures ◽  
Stiffened Panels ◽  
Post Buckling ◽  
Key Issues ◽  
Optimisation Techniques ◽  
Optimisation Algorithms

Stiffened panels made out of isotropic or anisotropic materials are being extensively used as structural elements for aircraft, maritime, and other structures. In order to maintain stiffness and strength with light weight, new design techniques must be employed when utilising these materials. Their stability, ultimate strength and loading capacity are the key issues pertaining to these engineering structures which have attracted a number of investigators to undertake in- depth research, either in an academic or actual engineering context. This paper presents a review of the optimisation techniques applied to buckling and post-buckling of stiffened panels. Papers published in the period from 2000 to May 2015 have been taken into consideration. The topic is addressed by identifying the most significant objectives, targets and issues, as well as the optimisation formulations, optimisation algorithms and models available. Finally a critical discussion, giving some practical advice and pointing out and post-buckling of stiffened panels, is provided. 

BUCKLING AND POST-BUCKLING OF ISOTROPIC AND COMPOSITE STIFFENED PANELS: A REVIEW ON ANALYSIS AND EXPERIMENT (2000-2012)

2021 ◽  
Vol 157 (A1) ◽  
Author(s):  
X-Y Ni ◽  
B G Prusty ◽  
A K Hellier
Keyword(s):  
State Of The Art ◽  
Shell Structures ◽  
Structural Elements ◽  
Engineering Structures ◽  
Broad Perspective ◽  
Stiffened Panels ◽  
Plate And Shell ◽  
Stiffened Structures ◽  
Post Buckling ◽  
Key Issues

Stiffened panels made out of isotropic or anisotropic materials are being extensively used as structural elements for aircraft, maritime, and other structures. In order to maintain stiffness and strength with light weight, new design techniques must be employed when utilising these materials. Their stability, ultimate strength and loading capacity are the key issues pertaining to these engineering structures which have attracted a number of investigators to undertake in- depth research, either in an academic or actual engineering context. This paper provides an extensive review of the research which has been conducted in recent years (2000-2012) on the buckling and post-buckling response of isotropic and composite stiffened plate and shell structures related to analysis and experiment. The key objective of this review article is to collate the research performed in the area of buckling and post-buckling behaviour of stiffened structures, thereby giving a broad perspective of the state-of-the-art in this field.

Buckling and Post-Buckling of Isotropic and Composite Stiffened Panels: A Review on Analysis and Experiment (2000-2012)

2015 ◽  
Vol 157 (A1) ◽  
pp. 9-30
Keyword(s):  
State Of The Art ◽  
Shell Structures ◽  
Structural Elements ◽  
Engineering Structures ◽  
Broad Perspective ◽  
Stiffened Panels ◽  
Plate And Shell ◽  
Stiffened Structures ◽  
Post Buckling ◽  
Key Issues

"Stiffened panels made out of isotropic or anisotropic materials are being extensively used as structural elements for aircraft, maritime, and other structures. In order to maintain stiffness and strength with light weight, new design techniques must be employed when utilising these materials. Their stability, ultimate strength and loading capacity are the key issues pertaining to these engineering structures which have attracted a number of investigators to undertake indepth research, either in an academic or actual engineering context. This paper provides an extensive review of the research which has been conducted in recent years (2000-2012) on the buckling and post-buckling response of isotropic and composite stiffened plate and shell structures related to analysis and experiment. The key objective of this review article is to collate the research performed in the area of buckling and post-buckling behaviour of stiffened structures, thereby giving a broad perspective of the state-of-the-art in this field."

Optimization of lightweight sub-stiffened panels with buckling analysis and imperfection sensitivity analysis

2019 ◽  
Vol 233 (15) ◽  
pp. 5507-5521 ◽  
Author(s):  
Hao Chen ◽  
Yuanming Xu ◽  
Junhao Hu ◽  
Xi Wang
Keyword(s):  
Sensitivity Analysis ◽  
Ultimate Strength ◽  
Multidisciplinary Optimization ◽  
Uniaxial Loading ◽  
Stiffened Panel ◽  
Imperfection Sensitivity ◽  
Engineering Structures ◽  
Buckling Loads ◽  
Stiffened Panels ◽  
Post Buckling

On the purpose of improving the structural efficiency of stiffened panels, which is widely used in engineering, three promising layouts of sub-stiffened thin-walled structures were optimized in view of structure's initial buckling and further analyzed through post-buckling and imperfection-sensitivity analysis. The optimization tasks were carried out using an integrated framework, which is based on the multidisciplinary optimization platform Model Center and finite element method software ABAQUS. The particle swarm optimization algorithm was applied to optimize layout parameters. Three optimal sub-stiffened panels were then evaluated based on their performance on critical buckling loads and post-buckling ultimate strength under uniaxial loading. Imperfection-sensitivity analysis was also conducted to investigate the stability behavior of the proposed panels with defect. The results indicate that the introduction of sub-stiffeners into the traditional stiffened panel can achieve significant improvements on the panel's buckling loads and ultimate strength under uniaxial loading, which are favorable to expand design space for engineering structures under requirements of lightweight with high bending stiffness and bucking resistance.

scholarly journals Research and practice

2014 ◽  
Vol 70 (6) ◽  
pp. 1039-1053 ◽  
Author(s):  
Mark Hepworth ◽  
Philipp Grunewald ◽  
Geoff Walton
Keyword(s):  
Phenomenological Approach ◽  
Critical Discussion ◽  
Research Literature ◽  
Research Experience ◽  
Content Type ◽  
Information Behaviour ◽  
Relative Value ◽  
Participative Approach ◽  
Key Issues ◽  
Participative Design

Purpose – The purpose of this paper is to provide a critical discussion on the nature of research into people's information behaviour, and in particular the contribution of the phenomenological approach for the development of information solutions. Design/methodology/approach – The approach takes the form of a conceptual analysis drawing on the research literature and personal research experience. Findings – The paper brings to the foreground the relative value of different conceptual approaches and how these underpin and relate to the development of information solutions. Research limitations/implications – The paper, due to the breadth and complexity of the subject, serves to highlight key issues and bringing together ideas. Some topics deserve further explanation. However, this was beyond the scope of this paper. Practical implications – A conceptual framework is provided that indicates the value of the epistemic spectrum for information behaviour studies and provides support for action research and participative design. Social implications – Taking a phenomenological approach, and consequently either a first person approach and/or a highly participative approach to research, challenges the relationship between researcher and respondent. It also raises questions about why the authors conduct research and for whom it is intended. Originality/value – The paper makes explicit the underlying philosophical assumptions and how these ideas influence the way the authors conduct research; it highlights the significance of Cartesian dualism and indicates the significance of these assumptions for the development of information solutions. It supports the view that researchers and developers should be open to respondents leading the exploration of their needs.

The Effect of Stitching on Compression Behavior of Stiffened Composite Panels

2001 ◽  
Author(s):  
Sung S. Suh ◽  
H. Thomas Hahn ◽  
Nanlin Han ◽  
Jenn-Ming Yang
Keyword(s):  
Beneficial Effect ◽  
Compression Behavior ◽  
Stiffened Panels ◽  
Shell Elements ◽  
Stitch Density ◽  
Stiffened Composite Panels ◽  
Out Of Plane ◽  
Post Buckling ◽  
Post Impact ◽  
Good Agreement

Abstract Failure of stiffened panels under compression is preceded by buckling of their skin and hence is affected by the presence of out-of-plane stresses. One of the promising methods of preventing premature delamination is stitching. The present paper discusses the effect of such stitching on compression behavior of blade-stiffened panels that were fabricated from plain weave AS4/3501-6 through resin film infusion process. Kevlar 29 yarn was used at a stitch density of 9.92 stitches per cm2. Some of the panels were damaged by drop-weight impact before compression testing. For comparison purposes unstitched panels with the same materials and dimensions were also tested under the same loading conditions. Stitching resulted in a 10% improvement in strength in the absence of any intentional damage. The beneficial effect of stitching was most obvious when the panels were impacted on a flange: a 50% improvement was observed in post-impact strength. However, stitching could not prevent stiffener from failure when impacted directly. Thus stitching had no beneficial effect when impact occurred on a stiffener. A buckling and post-buckling analysis was carried out using 3-D shell elements on the Abaqus. Predictions were in fairly good agreement with the experimental data.

scholarly journals The flexural strength of anisotropic composite plates with free edges

2021 ◽  
Vol 21 (1) ◽  
pp. 26-34
Author(s):  
Ashot G. Akopyan ◽  
Keyword(s):  
Composite Materials ◽  
Stress State ◽  
Classical Theory ◽  
Solid Mechanics ◽  
Composite Plates ◽  
Operating Conditions ◽  
Plate Bending ◽  
Structural Elements ◽  
Engineering Structures ◽  
Anisotropic Composite

Modern technology shows increased demands on the strength properties of machines, their parts, as well as various structures, reducing their weight, volume and size, which leads to the need to use anisotropic composite materials. Finding criteria to determine the ultimate strength characteristics of structural elements, engineering structures is one of the urgent problems of solid mechanics. Strength problems in structures are often reduced to finding out the nature of the local stress state at the vertices of the joints of the constituent parts. The solution of this urgent problem for composite anisotropic plates can be found in this article, where the author continues the research in this area, extending them to the bending of anisotropic composite plates. The aim of the work is to study the limit stress state of anisotropic composite plates in the framework of the classical theory of plate bending. The outer edges of the plate are considered to be free. Using the classical theory of anisotropic plate bending in the space of physical and geometric parameters, the hypersurface equations determining the low-stress zones for the edge of the contact surface of a composite cylindrical orthotropic plate are obtained. Modern technological processes of welding, surfacing, soldering and bonding allow to produce structural elements of monolithic interconnected dissimilar anisotropic materials. The combination of different materials with qualities corresponding to certain operating conditions opens up great opportunities to improve the technical and economic characteristics of machines, equipment and structures. It can contribute to a significant increase in their reliability, durability, reduce the cost of production and operation. On this basis, the solution proposed in this work can be useful to increase the strength of composite materials.

Bromley's Family Law

2021 ◽  
Author(s):  
Nigel Lowe ◽  
Gillian Douglas ◽  
Emma Hitchings ◽  
Rachel Taylor
Keyword(s):  
Family Law ◽  
Hague Convention ◽  
Case Law ◽  
Critical Discussion ◽  
Genital Mutilation ◽  
Protection Orders ◽  
European Court ◽  
Key Issues ◽  
The Subject ◽  
Female Genital

Bromley’s Family Law has an enduring reputation as the definitive text on the subject. Its hallmark qualities of clarity, authority, comprehensiveness and readability have been relied upon by generations of readers. The text presents a broad treatment of the key issues relating to adult and child law. Each chapter provides an up-to-date critical discussion of the current legislative and case law position (including European Court of Human Rights’ decisions), proposals for reform and issues of current concern. Particular attention is also paid to the increasingly significant international dimension of family law, with a new chapter on this area covering the 1996 Hague Convention on the Protection of Children and reflecting the UK’s departure from the EU. This edition has been updated to provide up-to-date coverage on heterosexual civil partnerships, religious marriage (non)-recognition, the 2020 Domestic Abuse Bill, forced marriage protection orders, female genital mutilation protection orders, stalking protection orders, the Divorce, Dissolution and Separation Act 2020, online divorce, transgender parenthood, surrogacy, parental orders, child arrangement orders, radicalisation, and voluminous case law across all topics.

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