Research On Feature-based LCA Method For Double-knuckle Servo Press

In recent years, the equipment manufacturing industry has developed rapidly in China, which brings the problems on resource consumption and environmental emissions in the meantime. Under the background of global warming, how to take low carbon design becomes the focus and trend of future research. Life cycle assessment is widely used in all kinds of products at home and board as a tool of environmental impact assessment, and has received more and more attention. Therefore, applying this method to the press research is of great practical significance. But the data collection process in traditional LCA method is very multifarious, without considering the similar attributes that can be extracted in the design and manufacturing phase. This study will apply the feature-based thinking to LCA study aiming at the above problem.At first this paper builds a product data information model for LCA, which is composed of CAD, CAPP and feature-based LCA system, and the features in LCA for servo press are defined and classified. Feature selection, extraction and converison steps are added to the invent analysis link on the basis of the traditional LCA method to complete the overall framework of feature-based LCA method. Take the case study of typical LCA modeling process for example, some useful features in CAD and CAPP can be transferred to intermediate transformation parameters such as raw material input, energy and material consumption input, typical process input, and emissions output,and then they become the LCI results after future conversion process.Then the greenhouse gas emissions are chosen as LCA evaluation index. Raw material preparation, welding, casting, forging, machining and other processes involved in the manufacturing phase of servo press are taken as examples to analyze carbon type and source within them. The feature conversion model is completed on the basis of the different processes. Thus the conversion course from design and manufacturing features provided by CAD and CAPP to LCI is expressed definitely by the means of formulas. Due to the universality of manufacturing process, the conversion model is not only applicable for servo press, but also for other studies.Finally the application of feature-based LCA method is specified taking double-knuckle servo press for example. The research purpose and system boundary are determined at the first step. Then the carbon emissions in manufacturing, transportation, usage and waste processing phase are analyzed. After that the equivalent carbon emission of the whole life cycle is calculated using the related feature data from CAD, CAPP system and the conversion model. SimaPro software is used to get the LCI results for comparison and calculation to verify the scientifity of the model and Ecoindicator-99 method is taken to perform LCIA. The results show that usage phase accounts for 97.4 percent of total emission, which means energy conservation in the course of work is of vital significance from the point of driving technology. Raw material preparation is the main source of manufacturing phase which means lightweight design is also an effective way to reduce carbon emission on the premise of appropriate function and stiffness.