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Contact Analysis of the Two Dimensional Wheel-Rail Based on Finite Element Method
Issue:
Volume 3, Issue 5, September 2018
Pages:
71-79
Received:
2 September 2018
Accepted:
30 September 2018
Published:
30 November 2018
Abstract: Wheel-rail contact mechanics is one of the fundamental areas for studying wheel-rail relationship, therefore, the study of wheel/rail contact is of great significance to solve related problems. In this paper, simplified two dimensional rigid wheel-rail and resilient wheel-rail contact finite element models are established, and the reliability of the established models is verified by comparison of the finite element method and Hertz theory results. In the vicinity of the rail joint, the contact conditions do not satisfy the relevant hypothesis of Hertz theory, so the finite element method is used to investigate the wheel/rail contact analysis in rail joint. The results show that wheel-rail contact pressure, maximum equivalent stress, the plastic deformation areas, and δx of the rail increases with the distance decreasing of the contact point to the rail joint. By comparing rigid wheel and resilient wheel, we also can find that the contact pressure, the maximun equivalent stress and δx of the resilient wheel-rail are less than the rigid wheel-rail, and width of contact area is basically same as rigid wheel-rail. Therefore, the use of resilient wheel can reduce the wear between wheel and rail and reduce the collapse of rail joint.
Abstract: Wheel-rail contact mechanics is one of the fundamental areas for studying wheel-rail relationship, therefore, the study of wheel/rail contact is of great significance to solve related problems. In this paper, simplified two dimensional rigid wheel-rail and resilient wheel-rail contact finite element models are established, and the reliability of th...
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Additive Manufacturing Technology Development: A Trajectory Towards Industrial Revolution
Onuh Ojogba Spencer,
Olatunbosun Tafa Yusuf,
Temidayo Christopher Tofade
Issue:
Volume 3, Issue 5, September 2018
Pages:
80-90
Received:
1 October 2018
Accepted:
25 October 2018
Published:
5 December 2018
Abstract: With the recent advancement in complexity of various technological products and the need for faster production, the quest for inventing new manufacturing technologies to reduce the design limitations such as the costs involved in purchasing and maintaining machines, the need for a trained operator, and increase in waste produced during machining in conventional manufacturing methods, has received significant boost in recent time with the advent of additive technology (AM) or 3D printing within various experts in industry, research & development institutes and universities, which invariably has not only enhanced deliverable on time and on budget of products, as well as ability to fabricate complex geometry with high precision and weight reduction. Several types of additive manufacturing (AM) that use different technologies and materials have emerged, in which the 3D systems are used to produce objects through adding rather than subtracting materials, transforming essentially detailed design files to fully functional products, to directly or indirectly alleviate the burden associated with convectional manufacturing and assembly methods. In this paper, an extensive review has been done on several methods adopted in 3D printing. Example include: Fused Filament Fabrication (FFF), Selective Laser Sintering (SLS), Continuous Filament Fabrication (CFF), Stereolithography (SLA), Atomic Diffusion Additive Manufacturing (ADAM) and Selective Laser Melting (SLM). The various steps involve in operation and working principle of 3D printing technology was also stated. The paper also presents the applicable areas of 3-D printing focusing on tooling, aviation/aerospace, medical/biomechanical and city planning.
Abstract: With the recent advancement in complexity of various technological products and the need for faster production, the quest for inventing new manufacturing technologies to reduce the design limitations such as the costs involved in purchasing and maintaining machines, the need for a trained operator, and increase in waste produced during machining in...
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Research on the Rolling Motion Mode of a SWATH-USV
Qin Yuxuan,
Gao Shasha,
Yu Yongqiang,
Tang Yang,
Yang Songlin
Issue:
Volume 3, Issue 5, September 2018
Pages:
91-98
Received:
10 December 2018
Published:
11 December 2018
Abstract: This paper takes a SWATH-USV as the research object, and carries out a series of static water roll attenuation tests under different drafts and different initial roll angles. In order to study the roll motion mode of the SWATH-USV, we have established three mathematical models of the roll motion mode, and written the system identification software in C# language, based on the system identification theory and the genetic programming algorithm. Firstly, by calculating the predicted values of angular velocity under different drafts and different initial roll angles, the error between the test value and the fitted value was analyzed, and the consistency between the predicted value and the test result was found to be good, which proves the reliability of the system identification software. Secondly, through the further processing of the test data, the variation law of the torque coefficient affecting the rolling motion with the draft and the initial roll angle is preliminarily analyzed. Finally, the polynomial response surface method is applied to fit the equation containing the rolling hydrodynamic torque coefficient and the recovery moment coefficient, and the equation is found to be applicability. The analysis results and methods can provide reference for the study of the wave resistance of such USV, and provide important technical support for the subsequent optimization of the boat type.
Abstract: This paper takes a SWATH-USV as the research object, and carries out a series of static water roll attenuation tests under different drafts and different initial roll angles. In order to study the roll motion mode of the SWATH-USV, we have established three mathematical models of the roll motion mode, and written the system identification software ...
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The Impact of Reverse Logistics on Operational Performance
Zhang Yu,
Ma Tianshan,
Muhammad Faheem Ud Din
Issue:
Volume 3, Issue 5, September 2018
Pages:
99-104
Received:
10 December 2018
Published:
11 December 2018
Abstract: Logistics management is an integrated part of supply chain management. Reverse logistics is for all operations related to the reuse of products and materials. It is "the process of moving goods from their typical final destination for the purpose of recycling, reuse, capturing value, or proper disposal. Remanufacturing and refurbishing activities also may be included in the definition of reverse logistics." Growing green concerns and advancement of green supply chain management concepts and practices make it all the more relevant. The number of publications on the topic of reverse logistics has increased significantly over the past two decades. This research paper investigates the relationship between reverse logistics operation, environmental performance, and competitive advantage, financial and operational performance of pharmaceutical firms located in India. This research paper has been adopted simultaneous regression method to test hypothesis. The results indicate that all endogenous (operational, environmental and financial performance) except competitive advantage are positively and significantly correlated with reverse logistics operations, while competitive advantages and reverse logistics operations have insignificant relationship. In addition, due to adoption of reverse logistics, firms may increase their overall performance and increase the efficiency of manufacturing processes due to elimination of waste. Furthermore, implementing reverse logistics operations, more opportunities to firms to improve their products’ quality and reduce their end-to-end supply chain cost will take place.
Abstract: Logistics management is an integrated part of supply chain management. Reverse logistics is for all operations related to the reuse of products and materials. It is "the process of moving goods from their typical final destination for the purpose of recycling, reuse, capturing value, or proper disposal. Remanufacturing and refurbishing activities a...
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