ANSYS finite element design of an energy saving magneto-rheological damper with improved dispersion stability

M. M. Rashid,Md Meftahul Ferdaus,Muhammad Hasibul Hasan,Ataur Rahman 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.7

The magnetorheological (MR) damper is one of the utmost progressive applications of asemi-active damper. Uninterrupted controllabilityin both on and off state is an important factor of its plenitude application. Current research is attempting to make the damper more effectiveand efficient by minimizing the existing limitations such as MR fluid’s sedimentation, power consumption and temperature rising, anddesign optimization. We have broadly analyzed the optimization of MR dampers design with finite element simulation where various parametersof the MR damper have been considered for more accurate results. A prototype MR fluid has been prepared by coating the carbonyliron particles with xanthan gum to reduce sedimentation. The SEM and Turbiscan results noticeably verify the improved sedimentationstability. In addition, a power-saving MR damper model has been developed by finite element analysis using ANSYS software. Prolongedoperation raises the damper’s body temperature and degrades the performance. However, in this energy-saving MR damper modelthe temperature is not rising to a higher value compared to the conventional dampers, and consequently promotes damper efficiency.

Kinematics and nonlinear control of an electromagnetic actuated CVT system for passenger vehicle

Ataur Rahman,Sazzad Bin Sharif,Altab Hossain,A. K. M. Mohiuddin,A. H. M. Zahirul Alam 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.7

An electromagnetic actuated continuously variable transmission (EMA-CVT) system is developed by two sets of electromagnetic actuators (solenoid) located on primary and secondary pulley. A set of solenoids are attached to the primary and secondary pulley to develop the attraction and repulsive forces. The relationships between the speed ratio and electromagnetic actuation and clamping force and output torque of the CVT are established based on the kinematics of the EMA-CVT system. A fuzzy logic controller (FLC) is developed to control the EMA precisely based on the feedback of the RPM sensor and slope sensor. The EMA-CVT performance with controller has found 28% more than the performance of the EMA-CVT without controller. The solenoids of the EMA were activated by varying the current supply with the Fuzzy-Proportional-Derivative-Integrator (FPID) to maintain the non-linearity of the CVT in response of the vehicle traction torque demand. Result shows that the solenoid is able to pull the plunger in the desired distance with supply current of 12.5 amp while push the plunger to the desired distance with 14.00 amp current supply to the windings when the vehicle is considered in 10% grade. The acceleration time of the ¼ scale car has been recorded as 5.5 s with the response of drive wheels torque.

Energy efficient electromagnetic actuated CVT system

Ataur Rahman,Sazzad Bin Sharif,A.K.M. Mohiuddin,Mahbubur Rashid,Altab Hossain 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.4

A continuously variable transmission (CVT) system transmits the engine/battery power to the car driving wheel smoothly and efficiently. Several types of CVT already been developed to improve the transmission losses while maintaining acceleration time. However,most of the CVT has some constraints in the actuation mechanism which led us to develop an innovative electromagnetic actuator forCVT. Simplified mathematical equations have been developed for the kinematics analysis of clamping forces of the CVT and electromagneticforces of EMA. The EMA has been developed for ¼ scale car with two sets of solenoid. Each of the two sets has been equippedwith primary and secondary pulleys for pushing and pulling the movable sheave. The solenoid is operated by controlling the supply currentwith a fuzzy logic controller. A simulation based fuzzy logic controller has been introduced here for identifying the desired current ofthe EMA actuation. The experimental results show that the EMA develops electromagnetic forces 301 N for the supply current of 3.37amp, which makes the acceleration time of the car in the range of 2.5~3.5 sec and electromagnetic actuated CVT system highly energyefficient.

Cushion pressure control system for an intelligent air-cushion track vehicle

Altab Hossain,Ataur Rahman,A.K.M. Mohiuddin 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.4

This paper presents the control system of cushion pressure for the developed intelligent air-cushion track vehicle (IACTV) for operating on swamp terrain and wet fields. A novel auto-adjusting supporting system is designed for the vehicle’s intelligent air-cushion system. Focusing on minimizing the total power demand of the vehicle, an optimization model has been established, for examining the effects of vehicle parameters and load distribution on power consumption by controlling air-cushion pressure. Then optimum cushion pressure is determined based on the developed optimum pressure – sinkage relationship and the pressure in the cushion chamber is controlled by the Fuzzy controller by maintaining volume flow rate and continuously monitored by the pressure sensor attached with the cushion chamber. The ultrasonic displacement sensor is used to measure the sinkage of the vehicle. The output voltages of the ultrasonic displacement are used to operate the pull-in solenoid switch through the microcontroller which closes the circuit of the compressor motor. Distribution of vehicle load to the air-cushion system is controlled by Fuzzy Logic controller by maintaining the inside pressure of the cushion.

Enterohepatic Recycling of Estrogen and its Relevance with Female Fertility

Sher, Alam,Rahman, M.Ataur The Pharmaceutical Society of Korea 2000 Archives of Pharmacal Research Vol.23 No.5

Enterohepatic recycling of estrogen after oral administration of 1 mg non-radioactive estriol was studied in fourteen women selected as the control subjects and ten infertile women in whom the infertility was appearing to be of endocrine origin. The extent of enterohepatic recycling of estriol ($E_3$) during the early follicular phase of menstrual cycle was assessed by monitoring during 48 h the urinary excretion of its two major metabolites i.e; estriol 16 $\alpha$-glucuronide ($E_3-16$$\alpha-G$) and estriol-3 glucuronide ($E_3$-3-G). The change in urinary level of $E_3$-3-G with respect to ($E_3-16$$\alpha-G$G was considered to reflect the extent of enterohepatic recycling of estriol. Lower values of urinary output of both metabolites in the infertile women as compared with the control subjects and the urinary excretion profile of both metabolites during 48 h after estriol ingestion reveal that the reduced extent of enterohepatic recycling could possibly be one of the factors which contribute towards the incidence of infertility in women.

Assessment of Infestation and Yield Loss by Stem Borers on Variety of Rice

Md. Touhidur Rahman,M. Khalequzzaman,M. Ataur Rahman Khan 한국응용곤충학회 2004 Journal of Asia-Pacific Entomology Vol.7 No.1

The extent of damage and yield loss due to six species of stemborers were studied on 9 (nine) rice varieties, in vegetative, reproductive and mature phases of the plant. The hybrid variety was found the most susceptible against all the borers, and local varieties were resistant. The percentage yield loss due to stemborer's infestation was found highest (27.09, 24.54, 25.32, 36.26, 17.74 and 22.19% by C. polychrysa (Meyrick), C. suppressalis (Walker), C. partellus (Swinhoe), S. incertulas (Walker), S. innotata (Walker) and S. inferens (Walker) respectively) on the variety, BR31 and lowest (11.17, 10.18, 10.54, 8.77, 8.10, and 7.07% by C. polychrysa, C. suppressalis, C. partellus, S. incertulas, S. innotata and S. inferens respectively) on the variety, Bansphul. Yield loss was found positively correlated with dead heart' and/or white head' infestations of vegetative, reproductive and mature phases of the crop.Key words Chilo, growth phase, rice varieties, Scirpophaga, Sesamia, varietal susceptibility, yield loss