Study On Multi-material Selection For Automotive Body Assembly Incorporating High Recyclability

The autobodyis an important part of the vehicle,which weightaccounted for about40%ofits own weight.Because of about70%fuel in the process of runningconsumptionin theautobody, so in lightweight designs, weight reduction by using multi-materials will reduceCO2emission and increase fuel economy, which will significantly reduce environmentalimpact. Owing to the importance of reducing CO2emission, automotive designs need tofulfill legislation requirements by attaining higher recyclability value. In this regard, anautomotive should be highly recycled at the end of its life in order to extend the use ofmaterials.In response to this problem, this paper presents a novel multi-material selection methodfor lightweight design, which incorporates recyclability for an automotive body assembly.The method is implemented in a real case study during the conceptual design phase in orderto demonstrate its applicability in product design. The proposed method will assist designersto select the optimal combination of multi-materials for lightweight designs, taking intoaccount its recyclability.Multi-material selection is considered as one of the design strategies implemented toattain product efficiency. Each product is different, and therefore several products mayrequire numerous functions that could not be satisfied by utilizing a single material. A designthat incorporates multi-material selection is a feasible alternative in order to achieve thefunctional requirements of a product.In the recyclability assessment, the recycling profit, recyclinginfrastructure, materialseparation, joint type and material combinationare taken as the factors which influencerecyclability. Theparameter profit is taken as the objective function in theGeneticAlgorithm (GA) optimization model as it is a numerical parameter.The remainingparameters are imprecise, and therefore it isdeemed suitable to represent these parameters inlinguistic form.A fuzzy system is utilized to develop recyclability assessmentwhich caters for uncertain data. Each parameter is expressed usinglinguistic language, with the exception ofthe profit parameter.This is also a method for capturing expert knowledge. Eachrecyclabilityfactor also has a specific weight taken from the recycler spreferences, whichwill be used in the GA optimization model.The R value MATLAB Graphical User Interfaceis designed specificallyto assist the designers in computing the recyclability value foraparticular design model without entering MATLAB environment.It is developed underMATLAB GUIDE that allows the builder to designand develop a GUI as well as loading theFIS function fromMATLAB through readfis and evalfis syntax. Screen of the userinterfaceare built as standalone application that can be called in differentsoftwareenvironment for easiness.Although several studies have been carried out on multi-material selection in productdesign, such studies are lacking on the use of multi-material selection based on materialrecyclability.In light of this, a method that is capable of guiding designers in multi-materialselection for lightweight designs taking into account product recyclability is proposed in thispaper. A multi-objective genetic algorithm is utilized to approximate the set of optimalsolutions in material selection, incorporating recyclability.