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Islam S.M.Z.,Rajshahi University of Engineering and Technology | Young B.,University of Hong Kong
Thin-Walled Structures | Year: 2013

Cold-formed stainless steel tubular structural members which may experience web crippling failure due to localise concentrated loads or reactions are investigated. A series of tests on fibre-reinforced polymer (FRP) strengthening of cold-formed stainless steel tubular structural members subjected to End-Two-Flange and Interior-Two-Flange loading conditions is presented. The strengthening only applied to a localise area of the members under concentrated load. A total of 58 web crippling tests were conducted. The investigation mainly focused on the effects of different surface treatment, different adhesive, and FRP for strengthening of stainless steel tubular sections against web crippling. The behaviour of stainless steel members strengthened by different widths of FRP plate against web crippling has been also investigated in this study. The test specimens consisted of ferritic stainless steel EN 1.4003 square and rectangular hollow sections. Two different surface treatments were considered. Furthermore, six different adhesives and six different FRPs were also considered in this study. The properties of adhesive and FRP as well as the bonding between the FRP and stainless steel tube have significant influence on the effectiveness of the strengthening. Most of the strengthened specimens were failed by debonding of FRP plates form the stainless steel tubes. Six different failure modes were observed in the tests, namely the adhesion, cohesion, combination of adhesion and cohesion, interlaminar failure of FRP plate, FRP delaminating failure and web crippling failure. The failure loads, failure modes, and the load-web deformation behaviour of the ferritic stainless steel sections are presented in this study. It was found that the web crippling capacity of ferritic stainless steel tubular sections may increase up to 51% using FRP strengthening. © 2012 Elsevier Ltd. All rights reserved. Source

Bari M.W.,Rajshahi University of Engineering and Technology | Shahin M.A.,Curtin University Australia
Geotextiles and Geomembranes | Year: 2014

The design of soil consolidation via prefabricated vertical drains (PVDs) has been traditionally carried out deterministically and thus can be misleading due to the ignorance of the uncertainty associated with the inherent variability of soil properties. To treat such uncertainty in the course of design of soil improvement by PVDs, more rational probabilistic methods are necessary. In this paper, a simplified probabilistic method is proposed in which the inherent variability of the coefficient of consolidation, which is the most significant uncertain soil parameter that affects the consolidation process, is considered. An easy-to-use design procedure and charts are provided for routine use by practitioners. © 2013. Source

Halder P.K.,Jessore University of Science and Technology | Paul N.,Bangladesh University of Engineering and Technology | Beg M.R.A.,Rajshahi University of Engineering and Technology
Renewable and Sustainable Energy Reviews | Year: 2014

Bangladesh is energy starve country facing a severe power crisis for the last few decades because of inadequate power generation capacity compared with demand. The power generation of the country largely depends on the non-renewable (fossil fuel) energy sources, mainly on the natural gas as accounts 64.5% of recent installed capacity. This trend causes rapid depletion of non-renewable energy sources. Thus, it is necessary to trim down the dependency on non-renewable energy sources and utilize the available renewable resources to meet the huge energy demand facing the country. Most of the people living in rural, remote, coastal and isolated areas in Bangladesh have no electricity access yet. However, renewable energy resources, especially biomass can play a pivotal role to electrify those rural, remote, coastal and isolated areas in the country. Humankind has been using biomass as an energy source for thousands of years. This study assesses the bio-energy potential, utilization and related Renewable Energy Technologies (RETs) practice in Bangladesh. Improved cooking stove, biogas plant and biomass briquetting are the major RETs commonly practiced in Bangladesh. The assessment includes the potential of agricultural residue, forest residue, animal manure and municipal solid waste. The estimated total amount of biomass resource available for energy in Bangladesh in 2012-2013 is 90.21 million tons with the annual energy potential of 45.91 million tons of coal equivalent. The recoverable amount of biomass (90.21 million tons) in 2012-2013 has an energy potential of 1344.99 PJ which is equivalent to 373.71 TWh of electricity. © 2014 Elsevier Ltd. Source

Hosen M.A.,Rajshahi University of Engineering and Technology
Ain Shams Engineering Journal | Year: 2014

In this paper, a modified harmonic balance method based an analytical technique has been developed to determine approximate solutions for a strongly nonlinear oscillator with a discontinuous term which is arising from the motion of rigid rod on the surface without slipping. Usually, a set of nonlinear algebraic equations is solved in this method. However, analytical solutions of these algebraic equations are not always possible, especially in the case of a large oscillation. We have been compared the solution results of this method with the numerical solution in order to validate the approach and assess the accuracy of the solutions has been demonstrated and discussed. We found that, a second order modified harmonic balance method works very well for the whole range of initial amplitudes. The advantage of the using method is its simple procedure and gives almost similar results in comparison with the exact solution. © 2014 Production and hosting by Elsevier B.V. on behalf of Ain Shams University. Source

Mustafi N.N.,Rajshahi University of Engineering and Technology | Raine R.R.,University of Auckland | Verhelst S.,Ghent University
Fuel | Year: 2013

Among the different efforts towards the reduction in pollutant emissions from direct injection (DI) diesel engines, the use of gaseous fuels as a partial supplement for diesel fuel has been proposed by many researchers. An experimental investigation was performed to investigate the influence of dual-fuel combustion on the performance and exhaust emissions of a DI diesel engine fueled with natural gas (NG) and biogas (BG). The engine was operated at a constant speed of 1750 rpm and at two different loads: low (∼3 N m) and high (∼28 N m), which were about 10% and 85% respectively of the rated torque output of the engine at 1800 rpm. In this work, the combustion pressure and the rate of heat release were evaluated experimentally in order to analyze the combustion characteristics and their effects on exhaust emissions including particulate matter (PM) for single-fuel (diesel) and dual fuel combustion modes. In dual fuel mode, the peak cylinder pressure was found to be similar to diesel at 75% of the rated output of the engine. About 27-30% higher maximum net heat release rates were obtained for NG and biogas fueling respectively compared to diesel fueling. Longer ignition delays but shorter combustion durations were characterized for dual fueling operations. Specific NOx emissions for dual fueling was always lower than diesel fueling case. Significantly lower specific PM emissions but sharply increased unburned hydrocarbons (UHC) emissions were measured for biogas-diesel dual fuel operations as compared to diesel fueling. © 2013 Elsevier Ltd. All rights reserved. Source

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