سال انتشار: ۱۳۸۳
محل انتشار: نهمین کنگره ملی مهندسی شیمی ایران
تعداد صفحات: ۱۱
Gholamhossein Sodeifian – Department of Chemical Engineering, Faculty of Engineering, Arak University, Arak, Iran
Amir Khamsenezhad – Department of Chemical Engineering, Faculty of Engineering, Arak University, Arak, Iran
Adaptive Simulated Annealing (ASA), is a suitable method for determination of discrete relaxation spectra. In this paper, we obtain the discrete relaxation spectra using the AAA algorithm. The method is based on randomly generated trial values of relaxation moduli, i g , and relaxation times, i l . In any stage, the algorithm try to find the best set of relaxation moduli, i g , and relaxation times, i l . Also, it follow to reach the global optimization by passing many local optima. An advantage of the mrthod is that it does not require the function to be smooth (differentiable) or even continuous, which is a requirement for gradient method.The results of this approach is used for obtaining the discrete relaxation spectra of polypropylene and polybutadiene polymer materials from small strain oscillatory shear measurements. Comparing of the algorithm and experimantal results, one can observe the capability of the ASA algorithm to fit a relaxation spectrum with the fewest possile parameter. This method is shownto be robust and reliable.