This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder…
Abstract
This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder metallurgy and composite material processing are briefly discussed. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for 1994‐1996, where 1,370 references are listed. This bibliography is an updating of the paper written by Brannberg and Mackerle which has been published in Engineering Computations, Vol. 11 No. 5, 1994, pp. 413‐55.
Details
Keywords
This study examined changes in work precarity (i.e., job insecurity and income insecurity) and involuntary job loss following the start of the Great Recession in 2007 among people…
Abstract
This study examined changes in work precarity (i.e., job insecurity and income insecurity) and involuntary job loss following the start of the Great Recession in 2007 among people with and without disabilities. Using five waves of nationally representative data from the Americans' Changing Lives (ACL) panel study, the findings demonstrated that people with disabilities who had early experiences of income insecurity were more likely to experience later income insecurity than people without disabilities. Those who had a functional disability and experienced job insecurity and income insecurity at W1, in 1986, were also significantly more likely to experience involuntary job loss following the start of the Great Recession. These findings highlight the disproportionate impact of early work precarity for people with disabilities and are discussed as an application of the life-course concept of cumulative disadvantage.
Details
Keywords
The development of inclusive education, characterised by both universal momentum and geopolitical differences, has largely omitted children and young people with profound…
Abstract
The development of inclusive education, characterised by both universal momentum and geopolitical differences, has largely omitted children and young people with profound intellectual and multiple disabilities. For this group, access to educational opportunities at all has been slow to be won, and separation for ‘special care’ for their very high support needs is the norm. There have been advances in recognising the human rights and indeed humanity of people with the most profound intellectual disabilities, but the focus of educationalists has often been on how to foster and document fine-grained learning gains and on the specialist nature of the teaching they need. In this chapter, in contrast, the emphasis is on how the spirit of ‘Nothing about us without us’ can extend to children and young people with profound intellectual disabilities such that they are at the heart rather than periphery of the education and research process. The potential for belonging in education and research is illustrated through exploratory work on doing research inclusively with children with profound intellectual and multiple disabilities in two English special school classes. The starting point is seeking to know them from being with them in a particular way. The knowledge shared in the chapter is a mix of big picture state of the art overview and deep intersubjective knowledge/feeling created together with children with profound intellectual and multiple disabilities. The implications for future research in inclusion include the need to start from a different mindset in which belonging and reciprocity inform an asset-based approach.
Details
Keywords
Omri Rand and Vladimir Khromov
This paper aims to present an analytical insight into the effect known as lift offset. This effect may be of advantage in terms of power consumption when configurations that…
Abstract
Purpose
This paper aims to present an analytical insight into the effect known as lift offset. This effect may be of advantage in terms of power consumption when configurations that consists of two main rotors (coaxial, tandem, etc.) are operated at high speed forward flight. Fundamentally, each of the main rotors is producing a roll moment in opposite direction that is overall canceled to allow trim. The first-order phenomena of lift offset are therefore related to the load distribution over each rotor and may be analyzed independently of the interaction between the rotors.
Design/methodology/approach
Using simple analytical model, this paper analytically and explicitly evaluates the lift offset effect. It also demonstrates in a closed analytical form the various phenomena involved, including the optimal values obtained.
Findings
The paper shows that the main effect of lift offset is its influence on the lift coefficient distribution over the disk. It is also demonstrated that lift offset substantially reduces both the average and the azimuthal variation of the lift coefficient.
Originality/value
Comparison with numerical predictions shows adequate correlation. Overall, the insight provided may be use as a guideline for advance design of rotorcraft configurations of coaxial/tandem rotor systems.
Details
Keywords
Karen Renaud, Graham Johnson and Jacques Ophoff
The purpose of this paper is to reveal the lived experiences of dyslexics in engaging with all kinds of alphanumeric authentication mechanisms.
Abstract
Purpose
The purpose of this paper is to reveal the lived experiences of dyslexics in engaging with all kinds of alphanumeric authentication mechanisms.
Design/methodology/approach
A significant proportion of the world’s population experiences some degree of dyslexia, which can lead to spelling, processing, sequencing and retention difficulties. Passwords, being essentially sequences of alphanumeric characters, make it likely that dyslexics will struggle with these, even more so than the rest of the population. Here, this study explores the difficulties people with dyslexia face, their general experiences with passwords, the coping strategies they use and the advice they can provide to developers and others who struggle with passwords. This paper collects empirical data through semi-structured interviews with 13 participants. Thematic analysis was used to provide an in-depth view of each participant’s experience.
Findings
The main contribution of this paper is to provide evidence related to the inaccessibility dimensions of passwords as an authentication mechanism, especially for dyslexics and to recommend a solution direction.
Research limitations/implications
There is a possible volunteer bias, as this study is dealing with self-reported data including historical and reflective elements and this paper is seeking information only from those with self-declared or diagnosed dyslexia. Furthermore, many expressed interest or curiosity in the relationship between dyslexia and password difficulties, for some a motivation for their participation. Finally, given that the participants told us that dyslexics might hide, it is possible that the experiences of those who do hide are different from those who chose to speak to us and thus were not hiding.
Originality/value
A few authors have written about the difficulties dyslexics face when it comes to passwords, but no one has asked dyslexics to tell them about their experiences. This paper fills that gap.
Details
Keywords
The dramatic expansion in the use and capability of electronic devices in recent years has been facilitated by the substantial development of production techniques. Modern…
Abstract
The dramatic expansion in the use and capability of electronic devices in recent years has been facilitated by the substantial development of production techniques. Modern electronic circuits as used in the computer, defence, aerospace, vehicle and domestic appliance industries contain a great many joints and these have to be made reliably and economically without degrading sensitive circuit components. This article describes the major microjoining developments currently of interest to the microelectronics industry, with emphasis on the work conducted by the microjoining section of The Welding Institute, much of which has been directly sponsored by the UK Ministry of Defence (DCVD).
Yabo Guan, Farhang Pourboghrat and Woong‐Ryeol Yu
The purpose of this paper is to provide an axisymmetric model of tube hydroforming using a Fourier Series based finite element method.
Abstract
Purpose
The purpose of this paper is to provide an axisymmetric model of tube hydroforming using a Fourier Series based finite element method.
Design/methodology/approach
Fourier series interpolation function, which considerably reduces the size of the global stiffness matrix and the number of variables, is employed to approximate displacements. The material of the tube is assumed to be elastic‐plastic and to satisfy the plasticity model that takes into account the rate independent work hardening and normal anisotropy. Numerical solution obtained from an updated Lagrangian formulation of the general shell theory is employed. The axial displacement stroke (a.k.a. axial feed) during tube hydroforming is incorporated using Lagrange multipliers. Contact constraints and boundary friction condition are introduced into the formulation based on the penalty function, which imposes the constraints directly into the tangent stiffness matrix. A forming limit curve based on shear instability and experimental measurements are used as fracture criteria.
Findings
The results obtained from this new formulation are compared against the nonlinear finite element code ABAQUS and experimental measurements for isotropic and transversely anisotropic tube materials. The hoop and axial strains predicted with AXHD code compared excellently with those from ABAQUS FEM code using plane stress axisymmetric (SAX1) and four‐node shell (S4R) elements. However, in the case of aluminum, the numerically predicted maximum hoop strain underestimated the actual hoop strain measured from the tube bulging experiment.
Practical implications
The axisymmetric hydroforming program (AXHD) developed in this work is very efficient in simulating the free‐forming stage of the tube hydroforming process under simultaneous action of internal pressurization and displacement stroke.
Originality/value
Although Fourier Series based finite element method has been used in metal forming, the extended application presented in this paper is novel in the finite element analysis of tube hydroforming.
Details
Keywords
Elizabeth Pérez-Izaguirre, José Miguel Correa Gorospe and Eider Chaves-Gallastegui
This chapter reflects on how ethics was managed in Basque educational ethnographic research. Specifically, it addresses researcher positionality when relating to research…
Abstract
This chapter reflects on how ethics was managed in Basque educational ethnographic research. Specifically, it addresses researcher positionality when relating to research collaborators in an attempt to manage inclusive ethics in situ. Nowadays, most research is evaluated by an ethical review board that ensures adequate research practice. However, unexpected fieldwork events need to be managed in the field, and this chapter addresses the impact of these events on the relationship between researchers and collaborators. Influenced by a post-qualitative stance we posit that research collaborators should be included in the research process. It reflects on the data collected during an ongoing ethnographic study with higher education students. The method used includes several interview meetings between researchers and collaborators, multimodal representations of collaborators' learning, and participants' self-observations. In the interviews, participants' discourses, representations, and self-observations were collaboratively analysed. The ethnographic data from these meetings show how researchers use a collaborative approach to practise ethics. Through such meetings, the knowledge derived from the ethnographic data is co-constructed in a research relationship where participants engage in dialogue and negotiation about the discourse created around them. Based on this relationship, we propose the concept of inclusive ethics as a process requiring an honest, inclusive, and collaborative relationship with the research subject.
Details
Keywords
In the United States, first generation robots are doing die casting, forging, upsetting, plastic molding, machine loading, spot welding, assembly, glass tube handling, paint…
Abstract
In the United States, first generation robots are doing die casting, forging, upsetting, plastic molding, machine loading, spot welding, assembly, glass tube handling, paint spraying, conveyor loading, handling explosives and radio active materials, and many other jobs which as can be seen, cover many fields and fabricating industries. Figs 7–14 illustrate first generation robots in action on some of the jobs just mentioned.