Green Engineering Material Choice by Using Seven-star-cobweb-chart Assessment Method

摘要

In this study, we account for factors relate to energy, resource and environment during material choice, we give each of those factor a representative frame and construct a 'seven-star-cobweb-chart', each factor line be compartmentalized into four representative points, connect relative seven points in turn we constructs a green assessment polygon, area of the polygon stands for green degree of material. we can choose the best material by calculating the area. this method can be named seven-star-cobweb-chart method. According to the method, the smaller the area is, the better relative material is; considering distortion situation, we bring forward a series of weighting coefficients 'Qi,' then we can do by two steps to assess green degree of material: ①calculating whole coefficient Q, Q = ΠQi, if Q = 0, choose another material, if not, continue to do step ②, ②calculating equivalent area of polygon, choose the smallest one as the best material, in this paper, we also give the way to calculate the equivalent area of the polygon.