Search results
21 – 30 of 44Grzegorz Budzik, Tomasz Dziubek, Łukasz Paweł Przeszłowski, Bartłomiej Sobolewski, Mariusz Dębski and Małgorzata Ewa Gontarz
Manufacturing of products loaded with torque in an incremental process should take into account the strength in relation to the internal structure of the details. Incremental…
Abstract
Purpose
Manufacturing of products loaded with torque in an incremental process should take into account the strength in relation to the internal structure of the details. Incremental processes allow for obtaining various internal structures, both in the production process itself and as a result of designing a three-dimensional computer-aided design model with programmable strength. Finite element analysis (FEA) is often used in the modeling process, especially in the area of topological optimization. There is a lack of data for numerical simulation processes, especially for the design of products loaded with torque and manufactured additive manufacturing (AM). The purpose of this study is to present the influence of the internal structure of samples produced in the material extrusion (MEX) technology on the tested parameters in the process of unidirectional torsion and to present the practical application of the obtained results on the example of a spline connection.
Design/methodology/approach
The work involved a process of unidirectional torsion of samples with different internal structures, produced in the MEX technology. The obtained results allowed for the FEA of the spline connection, which was compared with the test of unidirectional torsion of the connection.
Findings
The performance of the unidirectional torsion test and the obtained results allowed us to determine the influence of the internal structure and its density on the achieved values of the tested parameters of the analyzed prototype materials. The performed FEA of the spline connection reflects the deformation of the produced connection in the unidirectional torsion test.
Originality/value
There are no standards for the torsional strength of elements manufactured from polymeric materials using MEX methods, which is why the industry often does not use these methods due to the need to spend time on research, which is associated with high costs. In addition, the industry is vary of unknown solutions and limits their use. Therefore, it is important to determine, among others, the strength parameters of components manufactured using incremental methods, including MEX, so that they can be widely used because of their great potential and thus gain trust among the recipient market. In addition, taking into account the different densities of the applied filling structure of the samples made of six prototype materials commonly available from manufacturers allowed us to determine its effect on the torsional strength. The presented work can be the basis for constructors dealing with the design of elements manufactured in the MEX technology in terms of torsional strength. The obtained results also complement the existing material base in the FEA software and perform the strength analysis before the actual details are made to verify the existing irregularities that affect the strength of the details. The analysis of unidirectional torsion made it possible to supplement the material cards, which often refer to unprocessed material, e.g. in MEX processes.
Details
Keywords
It is axiomatic that, like other fields in the Social Sciences, value‐free development is non‐existent. A Growth or Redistribution‐With‐Growth Strategy, for instance, could not…
Abstract
It is axiomatic that, like other fields in the Social Sciences, value‐free development is non‐existent. A Growth or Redistribution‐With‐Growth Strategy, for instance, could not exist independently of the Neo‐Classical values. So are the Structuralist and Dependency Strategies: they did not emerge independently of the Marxist or Neo‐Marxist values. Irrespective of its origins, these mainstream development strategies have been associated with values of their own ideological world‐view especially when local customs and traditions involving indigenization of development are added, or independently, based on religious doctrines. All are obviously value‐loaded.
This research empirically analyzes gaps in performance among development stages of integration in supply chain management (SCM). The used variables are integration such as…
Abstract
This research empirically analyzes gaps in performance among development stages of integration in supply chain management (SCM). The used variables are integration such as internal and external and performance such as cost and service. The population is international freight forwarders in the Republic of Korea and the sample frame is the membership list of the Korean International Freight Forwarders Association. The used methodology in this research is various: Cronbach’s alpha, factor analysis, cluster analysis, analysis of variance and post hoc analysis. It is important to ascertain the position in which they are included and the position is concerned with internal integration and external integration because the aim of this research is to ascertain where the forwarders are in development stages of integration. According to prior research, development stages of integration are regarded as the flow from internal to external. However, this research suggests that development stages of integration do not explain the flow of the stages but explain the strategic choice concerned with their current decision-making.
Details
Keywords
Naoya Yotsumoto, Takeo Hirashima and Koji Toyoda
This paper aims to investigate the fire performance of composite beams when considering the hogging moment resistance of the fin-plate beam-to-girder joints including the effect…
Abstract
Purpose
This paper aims to investigate the fire performance of composite beams when considering the hogging moment resistance of the fin-plate beam-to-girder joints including the effect of continuity of reinforcements.
Design/methodology/approach
Experiments on composite beams with fin-plate joints protected only at the beam ends are conducted. The test parameter is the specification of reinforcement, which affects the rotational restraint of the beam ends. In addition, a simple method for predicting the failure time of the beam using an evaluation model based on the bending moment resistance of the beam considering the hogging moment resistance of the fin-plate joint and the reinforcement is also presented.
Findings
The test results indicate that the failure time of the beam is extended by the hogging moment resistance of the joints. This is particularly noticeable when using a reinforcing bar with a large plastic deformation capability. The predicted failure times based on the evaluation method corresponded well with the test results.
Originality/value
Recent studies have proposed large deformation analysis methods using FEM that can be used for fire-resistant design of beams including joints, but these cannot always be applicable in practice due to the cost and its complexity. Our method can consider the hogging moment resistance of the joint and the temperature distribution in the axial direction using a simple method without requirement of FEM.
Details
Keywords
Sheng Teng Huang, Emrah Bulut, Okan Duru and Shigeru Yoshida
The national logistics policy report published by Ministry of Land, Infrastructure and Tourism in 2011 proposes to establish international logistics strategy teams in 10 different…
Abstract
The national logistics policy report published by Ministry of Land, Infrastructure and Tourism in 2011 proposes to establish international logistics strategy teams in 10 different regions around Japan to satisfy the increasing demand for advance transportation infrastructure and stay competitive in Asia Pacific. The globalization of world economies creates many opportunities as well as challenges for international logistics companies to gain more business chances in this changing environment. The purpose of this paper is to improve service quality of international logistics companies and explores the quality function deployment in terms of quality evaluation method. The logistics service is particularly characterized by offering a series of transport solution and including other logistics activities. The major customers of the logistics services are the industrial clients. The customer satisfaction is key managerial mission since the competitiveness is a growing issue in this industry. The quality function deployment is one of the unique procedures to expose the requirements of customer and transform them into managerial tasks by cross correlation analysis between requirements and technical measures. The empirical study is performed to investigate service quality of the logistics industry by focusing on a group of leading logistics companies.
Details
Keywords
Civil wrongdoings with consequent financial and other loss or damage to employers, employees and third parties may result in the course of various trade union activities. These…
Abstract
Civil wrongdoings with consequent financial and other loss or damage to employers, employees and third parties may result in the course of various trade union activities. These day to day trade union activities take a variety of forms. The most common ones are inducement of breach of contract, conspiracy, trespass, nuisance, and intimidation. Each of these activities constitutes a tort which, unless the statutory immunities apply, would normally give rise at common law to an action for damages or, as is more frequent, enable the aggrieved party to obtain an injunction.
Xiaolong Lu, Shiping Zhao, Xiaoyu Liu and Yishu Wang
The purpose of this paper is to describe the design and development of “Pylon-Climber II”, a 5-DOF biped climbing robot (degree of freedom – DOF) for moving on the external…
Abstract
Purpose
The purpose of this paper is to describe the design and development of “Pylon-Climber II”, a 5-DOF biped climbing robot (degree of freedom – DOF) for moving on the external surface of a tower and assisting the electricians to complete some maintenance tasks.
Design/methodology/approach
The paper introduces a pole-climbing robot, which consists of a 5-DOF mechanical arm and two novel grippers. The gripper is composed of a two-finger clamping module and a retractable L-shaped hook module. The robot is symmetrical in structure, and the rotary joint for connecting two arms is driven by a linear drive mechanism.
Findings
The developed prototype proved a new approach for the inspection and maintenance of the electricity pylon. The gripper can reliably grasp the angle bars with different specifications by using combined movement of the two-finger clamping module and the retractable L-shaped hook module and provide sufficient adhesion force for the Pylon-Climber II.
Practical implications
The clamping experiments of the gripper and the climbing experiments of the robot were carried out on a test tower composed of some angle bars with different specification.
Originality/value
This paper includes the design and development of a 5-DOF biped climbing robot for electricity pylon maintenance. The climbing robot can move on the external surface of the electric power tower through grasping the angle bar alternatively. The gripper that is composed of a two-finger gripping module and a retractable L-shaped hook module is very compact and can provide reliable adhesion force for the climbing robot.
Details