چكيده به لاتين
In general, optimization problems contain more than one response, which often contradict each other. This research presents a multi-response optimization approach to determine the optimal mixture design of self-compacting concrete which is without a doubt a multi-response if multi criteria quality of the concrete are taken into consideration. The main contribution of this research is to demonstrate the application of the best-worst- based Taguchi method to solve multi-response optimization problems in which all qualitative indicators should satisfy the decision-maker's preferences. To demonstrate the efficiency of this method, it has been used to find an optimal mixing design for self-compacting concrete. Firstly, the criteria that determine the quality of concrete are determined, which include: heat transfer coefficient, air content, The T50 time, the water absorption, the compressive strength, the tensile strength and the cost of production, then, factors and levels that affect the performance of these qualitative criteria are determined using experts opinion. Five factors having three levels of control and one factor with two levels of control affect these qualitative criteria. After identifying these quality characteristics and control factors, optimal mixture design of concrete that satisfy decision makers preferences will be obtained. The values of self-compacting concrete quality characteristics will be obtained using scenarios that combine factor levels in the form of an orthogonal L18 array in Taguchi design. Then, using the best-worst method, the multi-response problem converts to a single-response problem, which first calculates the weight of the quality characteristics and then the weight of each experiments with respect to quality characteristics. In the last step, S/N values are calculated for each experiment, and optimal mixture design will be obtained using Taguchi method, optimal mixing is expected. Analysis of variance is then used to evaluate the significant factors. In order to verify the optimum mix-design proportion which is obtained by using the best worrst-based Taguchi method, an experimental study is performed. Finally to make the proposed method more realistic uncertainity is taken into account and the results are analyzed.
