Study Of Sustainability Assessment Method Of Machining Process With Environmental Factors Considered

Nowadays, manufacturing process not only produce products and make profit forthe enterprise, but also generate noise, a large amount of noxious gas and solid wastesdue to the physical and chemical changes in the process of metal material removal,thereby causing serious negative impact on the environment. Consequently, how toreduce the environmental pollution caused by manufacturing process is becoming a keyproblem urgently to be solved over the world. Quantitative analysis method for thefactors such as intensity of noise and pollution gas concentration that affect theenvironment can help accurately calculate the degree of environmental impact, and thenquantitatively evaluate the sustainability of machining process. In order to helpenterprise make reasonable decision to help improve the machining environment,comprehensive evaluation of the environmental impact of machining process based onAnalytic Hierarchy Process (AHP) has great practical value and realistic significanceunder the background of sustainable manufacturing.Chemical reaction equations of different chemical polishing process, namely acidicelectropolishing and electrolyte plasma polishing, are separately presented fornon-traditional machining technology in this paper. The chemical reaction mechanismof electropolishing is analyzed and the emission of gas pollution during acidicelectropolishing process is calculated quantitatively. Afterwards, a mathematical modelis built to simulate pollutant gas diffusion in the workshop based on the theory of gasdynamics. On the basis of real workshop, the physical model of workshop is built inGambit software. Meanwhile, the initial conditions and boundary conditions aredetermined separately. Based on the mathematical model of pollutant gases in theworkshop, the transportation and diffusion of sulfur dioxide are simulated in FLUENTsoftware. Finally, pollutant gas concentration distribution that achieving dynamicbalance is obtained.An effective approach is proposed to analyze environmental noise quantitativelycombined with common acoustic index in this paper. Mathematical model of noise onthe condition of multiple sound sources is built according to acoustics characteristic, theadditive principle of sound intensity and sonic wave attenuation theory. Then thenumerical simulation and quantitative analysis to environmental acoustic field ofworkshop are performed. The influence of equipment with high noise is analyzedquantitatively to achieve the prediction of environmental noise.In order to optimize workshop layout, a bi-objective mathematical model is built toobtain shortest makespan and minimum noise. Then the model is applied to a Flexible Manufacturing System (FMS) workshop, where a numerical simulation case study ispresented to introduce the application of this proposed methodology. The work flow ofFMS is simulated in Flexsim software to calculate the whole makespan. Additionally,noise prediction is performed based on the mathematical model of mix sound fieldproposed. Afterwards a series of existing problems in the current workshop layoutplanning are analyzed quantitatively. Finally, the utilization of Genetic Algorithm (GA)in solving workshop layout planning problems is presented in terms of geneticalgorithm flow, coding scheme, population generation, selection operator, crossoveroperator, fitness function, mutation operator and relative parameter settings.Environmental problems caused by manufacturing process are summarized.Besides, main factors influencing the environment are analyzed in detail. After ensuringthe qualitative and quantitative evaluation index, the hierarchical structure ofenvironmental impact assessment systematic model is built. Then matrix for comparisonand judgment is constructed. Consistency checks and the confirmation of the evaluationof target weight are presented for grade estimation of each decision, realizingquantitative analysis of the qualitative problem, which is solved based on AnalyticHierarchy Process (AHP). This quantitative analysis method can help enterprise makescientific decision with lower cost, that has practical significance for long-term andstable development of enterprise under the background of sustainable manufacturing.