Integrated shape and material selection for single and multi-performance criteria

A shape and material selection method, based on the concept of shape transformers, has been recently introduced to characterize the mass efficiency of lightweight beams under bending and shear. This paper extends this method to deal with the case of torsional stiffness design, and generalize it to single and multi-crieria selection of lightweight shafts subjected to a combination of bending, shear, and torsional load. The novel feature of the paper is the useful integration of shape and material to model and visualize multi-objective selection problems. The scheme is centered on concept selection in structural design, and hinges on measures that govern the shape properties of a cross-section regardless of its size. These measures, referred as shape transformers, can classify shapes in a way similar to material classification. The procedure is exemplified by considering torsional stiffness as a constraint. The performance charts are developed for single and multi-criteria to visualize in a glance the whole range of cross-sectional shapes for each material. Each design chart is explained with a brief example.     

Material selection based on ordinal data

Ranking and choosing the best material is one of most important stages in material selection process. Using linear assignment method, the multi-criteria decision making (MCDM) approach is proposed in decision-making process to rank the materials for a given engineering component with respect to several criteria. The proposed material selection procedure is relatively simple, and can be a useful approach when material selection problem includes qualitative properties or user-interaction aspects. The suggested approach also can be use for quantitative properties. Three examples are included to demonstrate the suggested method. Result of proposed approach showed good agreement with other methods.     

Filtration in materials selection and multi-materials design

Materials selection methods by free searching consist in four steps: translation, filtration, classification and documentation. The second step, limiting the field of solutions, must be analysed accurately when the constraints are related with free design parameters. This paper describes methods to deal with this filtration step in the cases of materials selection and multi-materials design. The classical filtration in single materials selection is extended to cases with several free geometric parameters. Then, a filtration approach for multi-materials design with undefined number of components and free geometric parameters is proposed. Finally, a case study concerning the design of a pipe material for offshore oil extraction is presented. The application of this work allows a preliminary elimination of unsuitable materials in the definition of multi-materials components, so it will be useful to avoid long numerical studies.     

The role of impressions on users’ tactile interaction with product materials: An analysis of associative concept networks

Depth impressions are an inner associative layer of humans’ expressed impressions. To analyze tactile interaction, it is essential to examine what users feel and imagine and how they create depth impressions by touching and looking at different product materials. On the basis of tactile interactions, this study aims to capture and analyze users’ depth impressions of materials. This research also proposes an ‘impressionably’ new tactile material for design from the viewpoint of depth impressions. To capture depth impressions, we investigated users’ tactile interactions in an experiment. The experiment used samples of six common natural and artificial materials, along with the proposed new micro-print-based material. A concept network-based method was employed in two stages to analyze the experimentally obtained verbalized protocols and to identify any depth impressions. This method allowed us to capture and analyze the depth impressions behind the surface impressions. This research found that the feel of materials’ tactile naturalness and users’ habituation to the tested samples are related to their depth impressions and the complexity of their concept networks. The depth impressions and concept network of the proposed micro-print material are distinct and beyond those for existing natural or artificial materials. These findings will provide the basis for employing new analysis tools and facilitate the development of impressionably better tactile materials for design.     

A study on the prediction of mechanical properties of titanium alloy based on adaptive fuzzy-neural network

An important trend in material research is to predict mechanical properties for a new titanium alloy before committing experimental resources. Often the prediction of mechanical properties of these alloys changes depending on their chemical composition and processing methods. Therefore, modeling the relationship between composition and property is crucial to the engineering. This study employs an adaptive fuzzy-neural network approach to predict the mechanical properties of titanium alloys. In adaptive fuzzy-neural network, to reduce the complexity of fuzzy models while keeping good model accuracy, a fuzzy clustering algorithm and a back-propagation learning algorithm are introduced to improve the accuracy of the simple model. For purpose of constructing this model, experimental results for 57 specimens with 14 different chemical compositions were gathered from the literature. The chemical composition contents were employed as the inputs while yield strength, tensile strength, elongation and reduction of area, which were employed as the outputs. Thus, the model can be trained by using the prepared training set. After training process, the testing data were used to verify model accuracy. It is found that there is insignificant difference between predict results and experimental value and the maximum relative error is less than 9%. It proved that the predictive performance of the clustering-based adaptive fuzzy-neural network modeling is available and effective in simulating the composition content and predicting the mechanical properties of titanium alloys.     

Materials’ tactile testing and characterisation for consumer products’ affective packaging design

Touch is one sense through which people judge consumer products. How materials’ properties influence these judgments is the topic of this paper. People’s sensorial or psycho-physical judgments (by touch) of the roughness, softness, slipperiness and warmth of 37 material samples are reported as well as their affective judgments, such as how pleasurable, exciting, indulgent, the samples felt. Physical measurements are also reported of the samples’ coarse and fine surface finishes, compliance, sliding friction and thermal contact properties. Relationships between the affective and sensorial judgments and the physical measurements are explored. A relational hierarchy is established from the physical measurements to the sensorial to the affective judgements. By following the dependencies in reverse, from the affective to the sensorial to the physical level, the required material surface properties to transmit intended affective messages to consumers might be determined. However, further work is needed on how to quantify some aspects of surface properties, particularly of roughness and sliding friction, in a manner useful for relating to affect. The methods described currently support communication and decision taking during the product development process.     

A novel hybrid multiple criteria decision making model for material selection with target-based criteria

In engineering design, the decision to select an optimal material for a particular product is a problem requiring multi-criteria decision analysis that involves both qualitative and quantitative factors. The evaluation of alternative materials may be based on imprecise information or uncertain data. Furthermore, there can be significant dependence and feedbacks between the different criteria for material selection. However, most existing decision approaches cannot capture these complex interrelationships. In response, this paper proposes a general framework for evaluating and selecting the best material for a given application. A novel hybrid multiple criteria decision making (MCDM) model combining DEMATEL-based ANP (DANP) and modified VIKOR is used to solve the material selection problems of multiple dimensions and criteria that are interdependent. Moreover, target-based criteria as well as cost and benefit criteria can be addressed simultaneously in the proposed model. Finally, an empirical case concerning the bush material selection for a split journal bearing is presented to illustrate the potential of the new model. The results show that the proposed method for material selection is effective and provides meaningful implications for designers and engineers to refer.     

A decision making methodology for material selection using an improved compromise ranking method

An ever increasing variety of materials is available today, with each having its own characteristics, applications, advantages, and limitations. In choosing the right material, there is not always a single definite attribute of selection and the designers and engineers have to take into account a large number of material selection attributes. This paper presents a logical procedure for material selection for a given engineering application. The procedure is based on an improved compromise ranking method considering the material selection attributes and their relative importance for the application considered. Two examples are included to illustrate the approach.     

A subjective and objective integrated multiple attribute decision making method for material selection

The selection of an optimal material for an engineering design from among two or more alternative materials on the basis of two or more attributes is a multiple attribute decision making (MADM) problem. The selection decisions are complex, as material selection is more challenging today. There is a need for simple, systematic, and logical methods or mathematical tools to guide decision makers in considering a number of selection attributes and their interrelations and in making right decisions. This paper proposes a novel MADM method for material selection for a considered design problem. The method considers the objective weights of importance of the attributes as well as the subjective preferences of the decision maker to decide the integrated weights of importance of the attributes. Furthermore, the method uses fuzzy logic to convert the qualitative attributes into the quantitative attributes. Three examples are presented to illustrate the potential of the proposed method.     

A comprehensive VIKOR method for material selection

In engineering design, material alternatives evaluate according to different criteria depending on the objectives of the problem. Performance ratings for different criteria are measured by different units, but in the decision matrix in order to have a valid comparison all the elements must be dimensionless. However, a lot of normalization methods have been developed for cost and benefit criteria, not only there has not been enough attention for engineering design situations in which approaching the target values are desirable but also the available methods have shortcomings. A new version of VIKOR method, which covers all types of criteria with emphasize on compromise solution, is proposed in this paper. The proposed comprehensive version of VIKOR also overcomes the main error of traditional VIKOR by a simpler approach. Suggested method can enhance exactness of material selection results in different applications, especially in biomedical application where the implant materials should possess similar properties to those of human tissues. Five examples are included to illustrate and justify the suggested method.     

Selection of materials using compromise ranking and outranking methods

Selection of proper materials for different components is one of the most challenging tasks in the design and development of products for diverse engineering applications. Materials play a crucial and important role during the entire design and manufacturing process. Wrong selection of material often leads to huge cost involvement and ultimately drives towards premature component or product failure. So the designers need to identify and select proper materials with specific functionalities in order to obtain the desired output with minimum cost involvement and specific applicability. This paper attempts to solve the materials selection problem using two most potential multi-criteria decision-making (MCDM) approaches and compares their relative performance for a given material selection application. The first MCDM approach is ‘Vlse Kriterijumska Optimizacija Kompromisno Resenje’ (VIKOR), a compromise ranking method and the other one is ‘ELimination and Et Choice Translating REality’ (ELECTRE), an outranking method. These two methods are used to rank the alternative materials, for which several requirements are considered simultaneously. Two examples are cited in order to demonstrate and validate the effectiveness and flexibility of these two MCDM approaches. In each example, a list of all the possible choices from the best to the worst suitable materials is obtained taking into account different material selection criteria. The rankings of the selected materials almost corroborate with those as obtained by the past researchers.     

Introducing a novel method for materials selection in mechanical design using Z-transformation in statistics for normalization of material properties

Optimum materials selection is a very important task in design process of every product. There are various materials selection methods like Ashby’s method or digital logic methods such as DL and MDL. In the present research work the Z-transformation method is proposed for scaling the material properties to overcome the shortcoming of MDL method. The results show that despite the simple scaling function used, the ranking procedure is as powerful as MDL method and even it is superior to MDL when it ranks the less important materials existing among a list of candidate materials.     

Selection and experimental evaluation of low-cost porous materials for regenerator applications in thermoacoustic engines

This paper aims at evaluating three selected low-cost porous materials from the point of view of their suitability as regenerator materials in the design of thermoacoustic travelling-wave engines. The materials tested include: a cellular ceramic substrate with regular square channels; steel “scourers”; and stainless steel “wool”. Comparisons are made against a widely used regenerator material: stainless steel woven wire mesh screen. For meaningful comparisons, the materials are selected to have similar hydraulic radii. One set of regenerators was designed around the hydraulic radius of 200 μm. This included the ceramic substrate, steel “scourers”, stainless steel “wool” and stacked wire screens (as a reference). This set was complemented by steel “scourers” and stacked wire screens (as a reference) with hydraulic radii of 120 μm. Therefore six regenerators were produced to carry out the testing. Initial tests were made in a steady air flow to estimate their relative pressure drop due to viscous dissipation. Subsequently, they were installed in a looped-tube travelling-wave thermoacoustic engine to test their relative performance. Testing included the onset temperature difference, the maximum pressure amplitude generated and the acoustic power output as a function of mean pressure between 0 and 10 bar above atmospheric. It appears that the performance of regenerators made out of “scourers” and steel “wool” is much worse than their mesh-screen counterparts of the same hydraulic radius. However cellular ceramics may offer an alternative to traditional regenerator materials to reduce the overall system costs. Detailed discussions are provided.     

Flexural strength and translucent characteristics of lithium disilicate glass–ceramics with different P2O5 content

Lithium disilicate glass–ceramics derived from the SiO₂–Li₂O–K₂O–Al₂O₃–ZrO₂–P₂O₅ system with different P₂O₅ content (from 0.5 mol.% to 2.0 mol.% at a step of 0.5 mol.%) were prepared for dental restorative application. Flexural strength of final glass–ceramics and translucent characteristics expressed in term of contrast ratio (CR) were measured. The interrelations between P₂O₅ content, microstructure and properties were discussed. Glass–ceramic with a P₂O₅ content of 1.0 mol.%, in which elongated rod-like Li₂Si₂O₅ crystals formed an interlocking microstructure, showed the highest flexural strength and suitable contrast ratio for dental restorative application.     

Evaluation the effects of edge banding type and thickness on the strength of corner joints in case-type furniture

Edge banding is used to cover the exposed sides of wood materials such as plywood, particleboard or medium-density fiberboard, giving the appearance of a solid (or more valuable) material. This study was carried out to determine the effects of the edge banding material, namely polyvinyl chloride (PVC), melamine and wood veneer, thickness of edge banding material (0.4, 1, and 2 mm), and wood composite panel type on the diagonal compression and tension strength properties of particleboard surfaced with synthetic resin sheet (LamPb) and MDF surfaced with synthetic resin sheet (LamMDF).     

Investigations the effects of fastener, glue, and composite material types on the strength of corner joints in case-type furniture construction

This study was carried out to determine the performance of different construction techniques on the diagonal compression and tension strength of case-type furniture corner joints, and to determine the effects on these joints of some factors including the type of joint, the type of composite board and the glue type. For this purpose, melamine-coated particleboard (MCP) and melamine-coated fiberboard (MCF) panels were bonded with polyvinyl acetate D3 (PVA D3), polyvinyl acetate D4 (PVA D4) and Desmodur VTKA (DVTKA) adhesives on spline joint (Sj), butt joints (Buj), biscuit joints (Bij), plain dowel joints (PDj), grooved dowel joints (GDj). It became evident that the diagonal tension and compression strength of the joints is influenced by panel material, type of adhesive and joints. The diagonal tension strength was greater than the diagonal compression strength of all L-type corner joints. The highest diagonal tension strength was obtained in MCF with DVTKA adhesive and GDj while highest diagonal compression strength was obtained in MCP with PVA D4 and Sj. In both tests, MCF corner joints were stronger than MCP corner joints. Furthermore, diagonal tension and compression strength of the joints glued with PVA D4 adhesive was higher than the similar joints glued with PVA D3 and DVTKA adhesives.     

A methodological framework for the triple bottom line accounting and management of industry enterprises

Since the 1970s the purpose of the environmental protection campaign has been to try to halt the gradual deterioration of our natural habitat. Reactive and pro-active strategies were developed to incorporate environmental and social concerns into economic development beyond regulatory compliance. In this research, we present a methodology to support the new era of sustainable development for all the three areas, which implements the triple bottom line (TBL) accounting mechanism by using quantitative models. A broad TBL framework is developed to track and categorize sustainability information at the corporate level through a sustainability index system. A ‘sustainability optimization’ model incorporates environmental and social costs and values into economic activities to support the decisions of the management. This methodology can help decision makers to make ‘green’ plans, and provide strategic directions for future development.     

Customers segmentation in eco-friendly hotels using multi-criteria and machine learning techniques

This study aims to investigate the travellers' choice behaviour towards green hotels through existing online travel reviews on TripAdvisor. Accordingly, a method combining segmentation and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) techniques was developed to segment travellers based on their provided reviews and to prioritize green hotel attributes based on their level of importance in each segment. The data were taken from travellers' online reviews of Malaysian eco-friendly hotels on TripAdvisor. The results showed that the sleep quality was one of the most imporant factors for eco-hotel selection in the majority of segments. The developed method in this study was able to analyse travellers’ reviews and ratings on eco-friendly hotels to identify the future choice behaviour and aid travellers in their decision-making process. The study provides new insights for hotel managers and green policy makers on developing environmental-friendly practices.