Research On Theory And Method Of Environmentally Conscious Design Improvement Based On Environmental Value Analysis

It is a global tendency for manufacturers to be concerned about the environment, which leads to the appearance of Green Design (GD). Green Design, also known as Sustainable Design, Design for Environment (DfE), or Environmental Conscious Design (ECD), aims to yield a product whose aggregate environmental impact is as small as possible. The research on theory and method of GD mostly focused on the qualitative analysis of environmental issue, which goes against the implementation and application of GD. This Dissertation presents the concept of Environmentally Conscious Design Improvement (ECDI) resorting to the quantitative analysis of product lifecycle environmental impact based on Life Cycle Assessment (LCA) and Life Cycle Impact Assessment (LCIA) method Eco-Indicator'99, and characterizes the systematic Environmental Value Analysis (EVA) method identifying the weak spot of original design scheme, further describes the specific improvement method for material selection and product recycling to consummate the weak spot.As one of the most important parts of GD, ECDI takes the environmental performance of product as one of the most significant design objectives. The detailed environmental design objectives and processes of the ECDI are described, and the ECDI process model is established. The integrating product model is presented based on the analysis of the information requirements of ECDI. Two methods of lifecycle environmental impact assessment, middle-point assessment and end-point assessment, are analyzed. The Eco-Indicator'99 method, known as a damage oriented method for life cycle impact assessment, is adopted as the end-point method.A systematic design improvement method called Environmental Value Analysis (EVA) is introduced, since this dissertation focuses on how to improve the product design with the quantitative analysis to minimize environmental impact of the product. EVA method pursues the feasible improvement strategies based on the former design scheme. The concept, objective, and application in the design process of Environmental Value Analysis were described. Firstly, transform the product structure system into function system through the Function-Structure mapping. Secondly, calculate the lifecycle environmental impact based on the function system. Thirdly, evaluate the environmental value. Finally, execute function analysis and improve the product design through retransforming the function system into improved structure system. The case study of reading lamp illuminates the application of the EVA method. EVA can be used to search the weak spots in the design and identify the targets of design improvement at two design levels, product function unit level and lifecycle task unit level of the function unit.Although the analysis process of EVA is quantitative, the identification of design improvementstrategies for the improvement targets is qualitative. To analyze the design improvement strategies quantitatively, environmentally conscious material selection problem and redesign improvement and optimization for recycling as the two important parts of ECDI, are discussed especially.The principles for material selection in ECDI are given, and the process of environmentally conscious material selection is analyzed. The concept of Environmental Performance Index (EPI) of structure integrating the traditional performance constraint is presented based on the Performance Index (PI) presented by M.F. Ashby. EPI is semi-quantitative. Ulteriorly, the multi-objective decision-making model is established based on the analysis of the objectives and restriction conditions of the material selection problem, which takes material lifecycle cost (C) and lifecycle environmental impact (El) as the two quantitative objective variables. The Possible Solutions Search Algorithm (PSSA) and TOPSIS method are used to solve the problem.Based on the analysis of the product recycling problem, five basic rules of design improvement for recycling are presented and quantified, including the lifecycle analysis, materials compatibility, recycling profit, environmental impact of recycling, and structural and physical interaction analysis. Modular Analysis (MA) is adopted to deduce the improvement strategies. Firstly, the problem of module forming for recycling is described. Secondly, Fuzzy Clustering Algorithm (FCA) is adopted to form the components cluster based on the fuzzy relation matrix that is established to denote the fuzzy relation between the parts according to one or several of the above five rules. Thirdly, the redesign improvement strategies are analyzed based on the different modular analysis results. An example of air-conditioner is demonstrated to illustrate such method.GD should reduce the product lifecycle environmental impact without compromising of other product performance such as lifecycle cost, quality, efficiency, manufacturability etc. Therefore there exist many complicated multi-objective and multi-criteria decision making problems to select the optimal redesign solution from the candidate design improvement schemes in the ECDI process. The framework to illustrate these problems is presented. Based on TOPSIS, the modified new method called Utility Similarity is demonstrated to solve the decision-making problems. The Utility Similarity method incorporates the non-linear normalization different from the commonly used linear method, and establishes optimization model to calculate the weight to make the decision-making process more objective.