http://ase.iust.ac.ir Automotive Science and Engineering - Journal articles for year 2012, Volume 2, Number 1 Yektaweb Collection - https://yektaweb.com en 2012/1/11 http://news.iust.ac.ir/ijae/browse.php?a_id=69&sid=1&slc_lang=en Car body lightening and crashworthiness are two important objectives of car design. Due to their excellent performance, composite materials are extensively used in the car industries. In addition, reducing the weight of vehicle is effective in decreasing the fuel consumption. Hat shape energy absorber is used in car’s doors for side impact protection. The aim of these numerical models and experimental tests is to unveil some important fact about using composite materials in hat shape energy absorber and also show the effect of orientation angles on the amount of energy absorption. The effects of different orientation angles on crushing behavior of hat shape structure are presented. N. Tavassoli http://news.iust.ac.ir/ijae/browse.php?a_id=97&sid=1&slc_lang=en H. Shojaeefard http://news.iust.ac.ir/ijae/browse.php?a_id=102&sid=1&slc_lang=en Temperature is one of the effective parameters in erosion of spark plug electrodes. In this research, temperature of spark plug was measured in engine's different operation conditions with two types of fuels: compressed natural gas and gasoline. Test results showed that, temperature of center electrode is lower than ground electrode and maximum difference between them is 110ºC that occurs at 2500 rpm and full load conditions. Maximum temperature of spark plug occurs with CNG under full load conditions and 6380 rpm. In these conditions, ground electrode’s temperature reaches to 960ºC which is very prone to pre-ignition. On the other hand, center electrode’s temperature is 195ºC higher than the same condition with gasoline as a fuel which cause more electrode erosion rate. This temperature rise lead to cold type spark plug selection because of its better heat transfer. Spark plug erosion was studied after endurance tests with CNG as a fuel. Electrodes have non uniform wear patterns and consequently gap growth is not uniform. The average gap growth for two sets of spark plugs after two similar 200 hr endurance tests is 49.6% Javan http://news.iust.ac.ir/ijae/browse.php?a_id=103&sid=1&slc_lang=en This paper develops an automatic parking algorithm based on a fuzzy logic controller with the vehicle pose for the input and the steering angle for the output. In this way some feasible reference trajectory path have been introduced according to geometric and kinematic constraints and nonholonomic constraints to simulate motion path of car. Also a novel method is used for parking space detection according to image processing. A fuzzy controller according to experiments of skilled driver and path planning is designed, and then fuzzy rules are tuned and finally fuzzy membership functions are optimized using genetic algorithm. Simulation results illustrate the effectiveness of the developed schemes Azadi http://news.iust.ac.ir/ijae/browse.php?a_id=104&sid=1&slc_lang=en the primary objective of this work is to introduce a gear ratio selection strategy for a CVT equipped vehicle and show its effectiveness on the fuel consumption reduction. AFuzzy control algorithm is designed for this purpose. Anonlinear model is developed for simulating the longitudinal vehicle dynamics with accelerator pedal applied by the driver as an input. In order that pedal input values can be used for evaluation of control strategy, a pedal cycle concept was introduced. With the help of these cycles different driving conditions were simulated and the fuel consumption results were obtained using Advisor software. Results showed that the control system was successful in reducing the fuel consumption, especially in low acceleration driving cycles Mashadi http://news.iust.ac.ir/ijae/browse.php?a_id=105&sid=1&slc_lang=en Car-following models, as the most popular microscopic traffic flow modeling, is increasingly being used by transportation experts to evaluate new Intelligent Transportation System (ITS) applications. A number of factors including individual differences of age, gender, and risk-taking behavior, have been found to influence car-following behavior. This paper presents a novel idea to calculate the Driver-Vehicle Unit (DVU) instantaneous reaction delay of DVU as the human effects. Unlike previous works, where the reaction delay is considered to be fixed, considering the proposed idea, three input-output models are developed to estimate FV acceleration based on soft computing approaches. The models are developed based on the reaction delay as an input. In these modeling, the inputs and outputs are chosen with respect to this feature to design the soft computing models. The performance of models is evaluated based on field data and compared to a number of existing car-following models. The results show that new soft computing models based on instantaneous reaction delay outperformed the other car-following models. The proposed models can be recruited in driver assistant devices, safe distance keeping observers, collision prevention systems and other ITS applications. Khodayari