Open Access. Powered by Scholars. Published by Universities.®
Science and Technology Studies Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Science and Technology Studies
Modeling Behaviour Of Railway Ballast In Prismoidal Apparatus Using Discrete Element Method, Gino O. Calderon Vizcarra, Sanjay Nimbalkar, Michele Dal Toe Casagrande
Modeling Behaviour Of Railway Ballast In Prismoidal Apparatus Using Discrete Element Method, Gino O. Calderon Vizcarra, Sanjay Nimbalkar, Michele Dal Toe Casagrande
Faculty of Engineering and Information Sciences - Papers: Part A
This article presents the results of numerical simulations of loading tests conducted on coarse particles that simulate railroad ballast. The objective of this study was to evaluate the deformation of ballast under vertical loading and to study the influence of the two different particle size distributions. One of them was according to particle size distribution recommended by Indraratna and co-workers in the past as an improvement to Australian Standard and the other was prepared in accordance with Brazilian standard. The discrete element method offers a new means of studying the response characteristics of railway ballast. The basic idea of discrete …
An Elasto-Plastic Method For Analysing The Deformation Of The Railway Ballast, Qideng Sun, Buddhima Indraratna, Sanjay Nimbalkar
An Elasto-Plastic Method For Analysing The Deformation Of The Railway Ballast, Qideng Sun, Buddhima Indraratna, Sanjay Nimbalkar
Faculty of Engineering and Information Sciences - Papers: Part A
In this study, a series of monotonically drained triaxial tests were conducted using the large-scale cylindrical triaxial apparatus. The effect of particle breakage and confining pressure on the mechanical behaviour of ballast were investigated. Based on the experimental findings, mathematical expressions for critical state stress ratio and specific volume are proposed to incorporate the evolution of particle breakage during monotonic shearing. An elasto-plastic constitutive model is formulated within the critical state soil mechanics framework in order to capture the stress-strain behaviour and degradation of ballast. The non-linear variation of shear strength envelope at a given range of confining pressures is …
Finite Element Method Analysis Of Surface Roughness Transfer In Micro Flexible Rolling, Feijun Qu, Haibo Xie, Zhengyi Jiang
Finite Element Method Analysis Of Surface Roughness Transfer In Micro Flexible Rolling, Feijun Qu, Haibo Xie, Zhengyi Jiang
Faculty of Engineering and Information Sciences - Papers: Part A
Micro flexible rolling aims to fabricate submillimeter thick strips with varying thickness profile, where the surface quality of products is mainly determined by initial workpiece surface roughness and subsequent surface asperity flattening process, which is affected by process parameters during rolling. This paper shows a 3D finite element model for flexible rolling of a 250 μm thick workpiece with reduction of 20 to 50%, and rolling phase with thinner thickness indicates a better ability to decrease the surface roughness. Four types of initial workpiece surface roughness are studied in the simulation, and the influences of process parameters, such as friction …
Thermal Performance Evaluation And Optimal Design Of Buildings With Integrated Air-Based Photovoltaic Thermal Collectors And Phase Change Materials Using The Hooke-Jeeves Pattern Search Method, Wenye Lin, Zhenjun Ma, Paul Cooper
Thermal Performance Evaluation And Optimal Design Of Buildings With Integrated Air-Based Photovoltaic Thermal Collectors And Phase Change Materials Using The Hooke-Jeeves Pattern Search Method, Wenye Lin, Zhenjun Ma, Paul Cooper
Faculty of Engineering and Information Sciences - Papers: Part A
Over the last several decades, many low energy technologies have been developed and deployed to reduce building energy consumption. Among various solutions, solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs) are among the most promising methods receiving increasing attention. This paper presents a thermal performance evaluation and optimal design of buildings integrated with air-based solar PVT collectors and PCMs embedded in the building envelope by using The Hooke-Jeeves pattern search method. The Hooke-Jeeves generalized pattern search is used to search for optimal solutions of the optimization problem. The variables optimized include the PVT air flow rate, additional wall …
Study On Micro Hydro-Mechanical Deep Drawing Using Finite Element Method, Xiaoguang Ma, Jingwei Zhao, Wei Du, Xin Zhang, Laizhu Jiang, Zhengyi Jiang
Study On Micro Hydro-Mechanical Deep Drawing Using Finite Element Method, Xiaoguang Ma, Jingwei Zhao, Wei Du, Xin Zhang, Laizhu Jiang, Zhengyi Jiang
Faculty of Engineering and Information Sciences - Papers: Part B
A numerical model was established to investigate the micro hydro-mechanical deep drawing process of austenitic stainless steel 304 foil (0.05 mm thickness). Due to the miniaturisation of the specimen size, the effect of grain size, gap distance and radial pressure during drawing process could be prominent. The results indicate that the appropriate radial pressure and gap distance could improve the limit drawing ratio (LDR) of manufactured cylindrical cups by reducing the friction resistance. The maximum LDR obtained in the present work reaches 3.2, which is much higher than that obtained by conventional deep drawing process.