Search results

1 – 10 of 800
Article
Publication date: 11 March 2019

Rohith P. George, Brad L. Peterson, Oliver Yaros, David L. Beam, Julian M. Dibbell and Riley C. Moore

To introduce blockchain in simple terms for business lawyers to be able to spot the right issues and ask the right questions.

4442

Abstract

Purpose

To introduce blockchain in simple terms for business lawyers to be able to spot the right issues and ask the right questions.

Design/methodology/approach

This article provides an overview of blockchain, identifies two example use cases, and highlights some of the most pressing legal issues, including issues to address in on-chain programming, off-chain agreements and other issues when determining whether to implement a blockchain solution.

Findings

This article concludes that there has been a significant growth in investment and interest in blockchain. Numerous companies across different sectors have developed blockchain proof-of-concepts, with some heading towards production deployments. At this point, commercial blockchain is largely in the pilot or proof-of-concept stage across a wide range of use cases, with payments and supply chain being two of the most promising use cases. This article also identifies possible legal issues associated with blockchain.

Practical implications

Despite the growing interest in blockchain, it is still a novel topic to many business lawyers. It is very important that lawyers are able to identify the right issues and ask the right questions.

Originality/value

Practical guidance from experienced lawyers in the Technology Transactions and Financial Services Regulatory & Enforcement practices.

Details

Journal of Investment Compliance, vol. 20 no. 1
Type: Research Article
ISSN: 1528-5812

Keywords

Article
Publication date: 27 September 2024

Elmira Sharabian, Mahyar Khorasani, Stefan Gulizia, Amir Hossein Ghasemi, Eric MacDonald, David Downing, Bernard Rolfe, Milan Brandt and Martin Leary

This study aims to comprehensively investigate the electron beam powder bed fusion (EB-PBF) process for copper, offering validated estimations of melt pool temperature and…

Abstract

Purpose

This study aims to comprehensively investigate the electron beam powder bed fusion (EB-PBF) process for copper, offering validated estimations of melt pool temperature and morphology through numerical and analytical approaches. This work also assesses how process parameters influence the temperature fluctuations and the morphological changes of the melt pool.

Design/methodology/approach

Two distinct methods, an analytical model and a numerical simulation, were used to assess temperature profiles, melt pool morphology and associated heat transfer mechanisms, including conduction and keyhole mode. The analytical model considers conduction as the dominant heat transfer mechanism; the numerical model also includes convection and radiation, incorporating specific parameters such as beam power, scan speed, thermophysical material properties and powder interactions.

Findings

Both the analytical model and numerical simulations are highly correlated. Results indicated that the analytical model, emphasising material conduction, exhibited exceptional precision, although at substantially reduced cost. Statistical analysis of numerical outcomes underscored the substantial impact of beam power and scan speed on melt pool morphology and temperature in EB-PBF of copper.

Originality/value

This numerical simulation of copper in EB-PBF is the first high-fidelity model to consider the interaction between powder and substrate comprehensively. It accurately captures material properties, powder size distribution, thermal dynamics (including heat transfer between powder and substrate), phase changes and fluid dynamics. The model also integrates advanced computational methods such as computational fluid dynamics and discrete element method. The proposed model and simulation offer a valuable predictive tool for melt pool temperature, heat transfer processes and morphology. These insights are critical for ensuring the bonding quality of subsequent layers and, consequently, influencing the overall quality of the printed parts.

Details

Rapid Prototyping Journal, vol. 31 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 12 September 2016

Joao Paulo C. Rodrigues, Luis Laim and Hélder David Craveiro

This paper aims to present the results of a study on the behaviour of cold-formed galvanized steel beams subjected to fire, using the results of a large programme of experimental…

Abstract

Purpose

This paper aims to present the results of a study on the behaviour of cold-formed galvanized steel beams subjected to fire, using the results of a large programme of experimental tests.

Design/methodology/approach

The research investigated the influence of web stiffeners in the sections and the stiffness of the surrounding structure, including the axial and rotational restraining to the thermal elongation, on the flexural behaviour of the beams in case of fire. In other words, the structural response of different open cold-formed steel beams, with and without web stiffeners, was compared in case of fire.

Findings

The results showed that a good choice between using cold-formed steel beams, with and without web stiffeners, may depend on the section shape and the internal forces generated in these members during a fire.

Originality/value

Temperatures in the furnace and at several points of the beams, as well as deformations and restraining forces and moments, were measured to achieve those goals and consequently to assess the critical time and temperature of these beams.

Details

Journal of Structural Fire Engineering, vol. 7 no. 3
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 1 June 1997

Jaroslav Mackerle

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the…

6101

Abstract

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

Details

Engineering Computations, vol. 14 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 12 December 2018

Siddharth Kulkarni, David John Edwards, Craig Chapman, M. Reza Hosseini and De-Graft Owusu-Manu

Road passenger transportation faces a global challenge of reducing environmental pollution and greenhouse gas emissions because of the vehicle weight increases needed to enhance…

Abstract

Purpose

Road passenger transportation faces a global challenge of reducing environmental pollution and greenhouse gas emissions because of the vehicle weight increases needed to enhance passenger safety and comfort. This paper aims to present a preliminary mechanical design evaluation of the Wikispeed Car (with a focus on body bending, body torsion and body crash) to assess light-weighting implications and improve the vehicle’s environmental performance without compromising safety.

Design/methodology/approach

For this research, finite element analysis (FEA) was performed to examine the Wikispeed chassis for light-weighting opportunities in three key aspects of the vehicle’s design, namely, for body bending the rockers (or longitudinal tubes), for body torsion (again on the rockers but also the chassis as a whole) and for crash safety – on the frontal crash structure. A two-phase approach was adopted, namely, in phase one, a 3D CAD geometry was generated and in phase, two FEA was generated. The combination of analysis results was used to develop the virtual model using FEA tools, and the model was updated based on the correlation process.

Findings

The research revealed that changing the specified material Aluminium Alloy 6061-T651 to Magnesium EN-MB10020 allows vehicle mass to be reduced by an estimated 110 kg, thus producing a concomitant 10 per cent improvement in fuel economy. The initial results imply that the current beam design made from magnesium would perform worst during a crash as the force required to buckle the beam is the lowest (between 95.2 kN and 134 kN). Steel has the largest bandwidth of force required for buckling and also requires the largest force for buckling (between 317 kN and 540 kN).

Originality/value

This is the first study of its kind to compare and contrast between material substitution and its impact upon Wikispeed car safety and performance.

Details

Journal of Engineering, Design and Technology, vol. 17 no. 1
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 19 September 2017

Puneet Kumar and J. Srinivas

The purpose of this paper is to perform a numerical analysis on the static and dynamic behaviors of beams made up of functionally graded carbon nanotube (FG-CNT) reinforced…

Abstract

Purpose

The purpose of this paper is to perform a numerical analysis on the static and dynamic behaviors of beams made up of functionally graded carbon nanotube (FG-CNT) reinforced polymer and hybrid laminated composite containing the layers of carbon reinforced polymer with CNT. Conventional fibers have higher density as compared to carbon nanotubes (CNTs), thus insertion of FG-CNT reinforced polymer layer in fiber reinforced composite (FRC) structures makes them sustainable candidate for weight critical applications.

Design/methodology/approach

In this context, stress and strain formulations of a multi-layer composite system is determined with the help of Timoshenko hypothesis and then the principle of virtual work is employed to derive the governing equations of motion. Herein, extended rule of mixture and conventional micromechanics relations are used to evaluate the material properties of carbon nanotube reinforced composite (CNTRC) layer and FRC layer, respectively. A generalized eigenvalue problem is formulated using finite element approach and is solved for single layer FG-CNTRC beam and multi-layer laminated hybrid composite beam by a user-interactive MATLAB code.

Findings

First, the natural frequencies of FG-CNTRC beam are computed and compared with previously available results as well as with Ritz approximation outcomes. Further, free vibration, bending, and buckling analysis is carried out for FG-CNTRC beam to interpret the effect of different CNT volume fraction, number of walls in nanotube, distribution profiles, boundary conditions, and beam-slenderness ratios.

Originality/value

A free vibration analysis of hybrid laminated composite beam with two different layer stacking sequence is performed to present the advantages of hybrid laminated beam over the conventional FRC beam.

Details

Multidiscipline Modeling in Materials and Structures, vol. 13 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Open Access
Article
Publication date: 26 July 2021

David Marschall, Sigfrid-Laurin Sindinger, Herbert Rippl, Maria Bartosova and Martin Schagerl

Laser sintering of polyamide lattice-based lightweight fairing components for subsequent racetrack testing requires a high quality and a reliable design. Hence, the purpose of…

Abstract

Purpose

Laser sintering of polyamide lattice-based lightweight fairing components for subsequent racetrack testing requires a high quality and a reliable design. Hence, the purpose of this study was to develop a design methodology for such additively manufactured prototypes, considering efficient generation and structural simulation of boundary conformal non-periodic lattices, optimization of production parameters as well as experimental validation.

Design/methodology/approach

Multi-curved, sandwich structure-based demonstrators were designed, simulated and experimentally tested with boundary conformal lattice cells. The demonstrator’s non-periodic lattice cells were simplified by forward homogenization processes. To represent the stiffness of the top and bottom face sheet, constant isotropic and mapped transversely isotropic simulation approaches were compared. The dimensional accuracy of lattice cells and demonstrators were measured with a gauge caliper and a three-dimensional scanning system. The optimized process parameters for lattice structures were transferred onto a large volume laser sintering system. The stiffness of each finite element analysis was verified by an experimental test setup including a digital image correlation system.

Findings

The stiffness prediction of the mapped was superior to the constant approach and underestimated the test results with −6.5%. Using a full scale fairing the applicability of the development process was successfully demonstrated.

Originality/value

The design approach elaborated in this research covers aspects from efficient geometry generation over structural simulation to experimental testing of produced parts. This methodology is not only relevant in the context of motor sports but is transferrable for all additively manufactured large scale components featuring a complex lattice sub-structure and is, therefore, relevant across industries.

Details

Rapid Prototyping Journal, vol. 27 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 13 February 2019

Abdurra’uf Mukhtar Gora, Jayaprakash Jaganathan, Mohammed Parvez Anwar and Hau Y. Leung

The purpose of this paper is to present the results of experimental and theoretical studies on the flexural capacity of reinforced concrete (RC) beams strengthened using…

Abstract

Purpose

The purpose of this paper is to present the results of experimental and theoretical studies on the flexural capacity of reinforced concrete (RC) beams strengthened using externally bonded bi-directional glass fibre reinforced polymer (GFRP) composites and different end anchorage systems.

Design/methodology/approach

A series of nine RC beams with a length of 1,600 mm and a cross-section of 200 mm depth and 100 mm width were prepared and externally strengthened in flexure with bi-directional GFRP composites. These strengthened beams were anchored with three different end anchorage systems namely closed GFRP wraps, GFRP U-wraps and mechanical anchors. All these beams were tested with four-point bending system up to failure. The experimental results are compared with the theoretical results obtained using the relevant design guidelines.

Findings

The experimental results demonstrate a significant increase in the flexural performance of the GFRP strengthened beams with regard to the ultimate load carrying capacity and stiffness. The results also show that GFRP strengthened beams without end anchorages experienced intermediate concrete debonding failure at the GFRP plate end, whereas all the GFRP strengthened beams with different end anchorage systems failed in rupture of GFRP with concrete crushing. The theoretical results revealed no significant difference among the relevant design guidelines with regard to the predicted ultimate moment capacities of the bi-directional GFRP strengthened RC beams. However, the results show that ACI Committee 440 Report (2008) design recommendation provides reasonably acceptable predictions for the ultimate moment capacities of the tested beams strengthened externally with bi-directional GFRP reinforcement followed by FIB Bulletin 14 (2001) and eventually by JSCE (1997).

Originality/value

The research work presented in this manuscript is authentic and could contribute to the understanding of the overall behaviour of RC beams strengthened with FRP and different end anchorage systems under flexural loading.

Details

International Journal of Structural Integrity, vol. 10 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Content available

Abstract

Details

Kybernetes, vol. 41 no. 7/8
Type: Research Article
ISSN: 0368-492X

Article
Publication date: 1 March 2003

Alan J. Dutson, Kristin L. Wood, Joseph J. Beaman, Richard H. Crawford and David L. Bourell

Functional testing of rapid prototypes (RP) represents an exciting area of research in solid freeform fabrication. One approach to functional testing is to use similitude…

Abstract

Functional testing of rapid prototypes (RP) represents an exciting area of research in solid freeform fabrication. One approach to functional testing is to use similitude techniques to correlate the behavior of an RP model and a product. Previous research at UT, Austin has resulted in the development of an empirical similitude technique for correlating the behavior of parts with different material properties. Advances in the empirical similitude technique are presented in this paper. Sources of coupling between material properties and geometric shape that produce distortions in the current empirical similitude technique are outlined. A modified approach that corrects such distortions is presented. Numerical examples are used to illustrate both the current and the advanced empirical similitude methods.

Details

Rapid Prototyping Journal, vol. 9 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

1 – 10 of 800