TIRE MODELS USED IN VEHICLE DYNAMIC APPLICATIONS AND THEIR USING IN VEHICLE ACCIDENT SIMULATIONS

Wheel model is very important in vehicle modelling, it is because the contact between vehicle and road is achieved by wheel. Vehicle models can be dynamic models which are used in vehicle design, they can also be models used in accident simulations. Because of the importance of subject, many studies including theoretical, experimental and mixed type have been carried out. In this study, information is given about development of wheel modelling and research studies and also use of these modellings in traffic accident simulations

SAFETY FACTOR IN VEHICLE DESIGN

One of the primary conciderations in vehicle design is safety. Safety criteria in the broadest sense have been with the car from its inception. Once you are moving at more than ten kilometers per hour, the problems of turning and stopping become immediately apparent. Designing for accident avoidance, therefore, is in one sense merely an extension of designing for normal function, and improvements have been introduced in an ad hoc manner over many years in this area. This paper traces very briefly the evolution of some safety aspects of vehicle design. Some studies and safety parameters are introduced too

The effect of thermal barrier coating on a turbo-charged Diesel engine performance and exergy potential of the exhaust gas

In this study, the effect of insulated combustion chamber surfaces on the turbocharged, direct injection Diesel engine performance was experimentally investigated. Satisfactory performance was obtained with the low heat rejection (LHR) engine. In comparison to a standard Diesel engine, specific fuel consumption was decreased by 6%, and brake thermal efficiency was increased by 2%. It was concluded that the exhaust gas process was the most important source of available energy, which must be recovered via secondary heat recovery devices. The available exhaust gas energy of the LHR engine was 3-27% higher for the LHR engine compared to the standard (STD) Diesel engine. However, it is impossible to recover all the exhaust gas energy in useful work. It is found that the maximum extractable power is less than 47% of the exhaust power. (C) 2004 Elsevier Ltd. All rights reserved

Biomechanical effects of daily physical activities on the lower limb

Objective: The aim of this study was to determine the joint torques on the lower extremity during the daily physical activity movements of sit-to-stand, crouch down-stand up, and stair climbing without using an external device.Methods: The study subject was a healthy 26-year-old male without any physical problems. A linksegment model was prepared according to the subject's individual anthropometric characteristics and transferred to the MATLAB® program. Joint torques were calculated using SimMechanics(TM) software. Motions were recorded by one digital video camera as the subject performed the movements (sit-tostand from 20 cm and 40 cm height, crouch down-stand up, and climbing 10 cm and 20 cm high step) and the joint's position data was obtained using a digitization process. In addition, the vertical ground reaction forces were measured using a force plate in order to test the accuracy of the link-segment model. Lower extremity joint torques were calculated.Results: Maximum joint torques occurred in the knee joint. The knee and the ankle joints were the most loaded joint during the high step movement. The highest torques of the knee and ankle joint were 157.2 Nm and 146 Nm, respectively, during the movements. Knee joint torque and the ankle joint torque increased when the sitting height increased. The hip joint experienced the least amount of load during the movements.Conclusion: The knee joint has enough strength against high torques during extension and flexion movement. Joint torques can be successfully calculated using a simulation process involving an inverse dynamics method without an external device mounted on the limbs. The obtained data can be used in the design of prosthetics and orthotics and for structural analysis of the bone

Catalytic reduction of NOx on vanadium exchanged natural zeolite using microwave irradiation

Zeolite-based catalysts are used commonly to control NOx emissions in selective catalytic reduction applications in lean combustion gasoline engines. In this study, a catalyst was prepared by ion-exchange of vanadium promoted using microwave irradiation, over the clinoptilolite type of natural zeolite to selectively reduce the nitrogen oxides, especially in lean combustion conditions with the HCs in the exhaust gas. According to experimental results, the maximum NOx conversion efficiency reached 28 % at temperature of 287 degrees C and space velocity of 30,000 h(-1)

Development of A Wearable Exercise Device for Rehabilitation of Hemiplegic Hand

Millions of people suffer a stroke each year. One of the problems after stroke is hemiplegic hand. In previous studies a lot of robotic based devices has been suggested for rehabilitation of hemiplegic hand. Actuators using for force transmitting in previous devices have some disadvantages. One of them is misalignment on the centre of rotation between joints used in devices and joints of the hand. In this study a novel device is suggested to perform the finger exercises. The device has a cable and spring driven mechanism with an electrical linear actuator. The device allows both passive and active exercises. It is aimed that the device is suitable for at-home use, wearable, portable and low cost. It is expected from the new device that it will reduces the rehabilitation cost and therapy period. The device can be used for other rehabilitation treatments such as nerve injury, nerve compression, tendon injury, fracture and sport injury besides stroke rehabilitation