International Conference on Mechanical Engineering and Advanced Technology - ICMEAT2012 10-12 October, 2012, Abbasi International Hotel, Isfahan, Iran ICMEAT2012-1546 Shape optimization of BELTs via genetic algorithm Seyed Alireza Moezi 1 , Ahmadreza Ghahramani 2 , Ehsan Zakeri 3 , Yousef Bazargan-Lari 4 , Babak Assadsangabi 5 1 Young Researchers Club, Shiraz Branch, Islamic Azad University, Shiraz, Iran; moezi2000@gmail.com 2 Department of mechanical engineering, Shiraz branch, Islamic Azad University, Shiraz, Iran; rezaghahramani87@gmail.com 3 Young Researchers Club, Shiraz Branch, Islamic Azad University, Shiraz, Iran; ehsan8631@gmail.com 4 Department of mechanical engineering, Shiraz branch, Islamic Azad University, Shiraz, Iran; bazargan@iaushiraz.ac.ir 5 Departmant of mechanical engineering, University of British Columbia, Vancouver, BC, Canada, babi.asad@gmail.com ABSTRACT In this study, different algorithms will be developed to compute optimal shapes and structures. Consequently, a new and advanced method of optimization not only for distinct shapes but also for non-significant ones is going to be illustrated. In this study, specifically, a specific shaped fragment called BELT will be analyzed. The optimization process is to optimize the fragment through the offices of genetic algorithms, somehow, to have the minimum weight and the ability to put up with the loading where as the generated tension stands under the range of the allowable limit. The main goal of the study is to focus on the existence of an optimal shaped fragment optimized by genetic algorithm, necessary conditions of optimality for the BELTs, and stability of optimal solutions under some prescribed perturbations. Keywords: Belt, Optimization, Genetic Algorithm, GAs Introduction Nowadays that it is not too hard to see the technology footmark in all mechanical systems, optimizing the industrial fragments is a vital concern in the design of them. Traditionally, engineers proceed by trial and error, and optimization is a matter of intuition and know-how. This is of course an old-fashion, costly, and imperfect process of optimizing. The current trend is to spend more and more numerical software's which simultaneously analyze and optimize many possible designs, making optimal design an automated process. Optimization makes the management of energy and resources, save time and costs, and ultimately, lead to greater accuracy of a device, and it’s easier to use [1- 4]. With the daily progress of technology, human needs the precise accessories to make better and more efficient use of these technologies. One technology that has created a significant change in human life is the car. This means of transport will ease a lot of human beings do, where to become one of the most essential tools in their daily lives were. With the passage of time and increasing the transportation vehicles and their variation, accuracy, convenience and safety of these devices in them had become a challenge. One of the devices that help to create safety for the occupants of these vehicles is a safety belt. In this article, a Belt, which is one of the most essential parts of a vehicles security system, is reviewed. By measuring the dimensions of a belt, the initial plan was drawn. Then, in order to have highly detailed design and analyses, the Comsol multiphysics had been choosed, which is based on the final element method (FEM). Comsol multiphysics had already been used in [4-6] as accurate software and their result shows the exactness of its analyses. By the use of Comsol, the initial analyses were performed on the model, and the rudimentary results were classified and were ready for the optimization process. For the optimization process, Genetic Algorithms (GAs), which were developed by John H. Holand [7] and is one the most powerful methods, had been chosen to have clear-out results. GAs has emerged as a useful tool for the heuristic solution of complex discrete optimization problems which is based on the concept of biological evolutionary process [6, 8]. During this process, dimensions, fillets and stress concentrated points had been investigated intently, so as to minimize the stress concentration and weight. Since one of the major in the design of the mechanical parts is their weight, an appropriate range was considered for the weight change during the optimization process. The paper is organized as follows: section 2 illustrates the modelling part and the initial shape of the model.