Engineering Design Methods Research Articles

Testing and evaluating the applicability and effectiveness of the new idea-configuration-evaluation (ICE) method of conceptual design

In a previous paper, we introduced the process of developing a new prescriptive method for conceptual engineering design called ICE (idea-configuration-evaluation), and demonstrated its application in detail. The new design model is based on the well-established theoretical foundation of C–K theory and the empirically derived parameter analysis method. In this paper, we describe the testing and evaluation of the model’s formulation through a design experiment that examines the performance of external participants when applying it. Two categories of evaluation metrics are used: applicability and effectiveness of the method. Nine quantitative and qualitative metrics describe aspects such as the ease of teaching and using the design procedure, and its support of creativity and innovation. The experiment took place in an academic environment and the results were obtained by analyzing detailed written design reports, assessing characteristics of the final solutions, and examining replies to reflective questionnaires. The conclusions from the study are that the ICE model presents a clear and concise step-by-step procedure, is conducive to teaching and practicing design, captures the dynamics and rationale of the conceptual design process, and can therefore lead to viable and innovative conceptual designs. Another, general contribution of the paper is in delineating the application of a plurality of measures in a non-comparative assessment of a design method.

Heuristic-Guided Solution Search Through a Two-Tiered Design Grammar

Abstract Grammar-based design is typically a gradual process; incremental design changes are performed until a problem statement has been satisfied. While they offer an effective means for searching a design space, standard grammars risk being computationally costly because of the iteration required, and the larger a given grammar the broader the search required. This paper proposes a two-tiered design grammar that enhances the computational design generation with generalized heuristics to provide a way to more efficiently search a design space. Specifically, this two-tiered grammar captures a combination of heuristic-based strategic actions (often observed in human designers) and smaller-scale modifications (common in traditional grammars). Rules in the higher tier are abstract and applicable across multiple design domains. Through associated guiding heuristics, these macrorules are translated down into a sequence of domain-specific, lower-tier microrules. This grammar is evaluated through an implementation within an agent-based simulated annealing team algorithm in which agents iteratively select actions from either the higher tier or the lower tier. This algorithm is used in two applications: truss generation, which is commonly used for testing engineering design methods, and wave energy converter design generation, which is currently a relevant research area in sustainable energy production. Comparisons are made between designs generated using only lower-tier rules and those generated using only higher-tier rules. Further tests demonstrate the efficacy of applying a combination of both lower-tier and higher-tier rules.

Design exploration of additively manufactured metamaterials

Additive manufacturing (AM) is making a profound impact on our ability to realize complex metamaterials and structures, but fully realizing the manufacturing freedom afforded by AM requires some significant advances in engineering design methods and tools. For some additive manufacturing applications, simulation-based design tools may be required to explore a hierarchy of features, ranging in size from microns to meters. At the same time, these tools need to provide real-time feedback on the constraints and process-structure-property relationships relevant to specific AM technologies, and this Design-for-AM feedback is needed during the design process, rather than at the end. To address these challenges, a design exploration approach has been established for creating inverse maps of promising regions of a hierarchical structural/material design space. The approach utilizes machine learning classifiers for identifying sets of promising solutions to a materials design problem, combined with statistical characterization of geometric features and material properties to ensure that the designs are robustly manufacturable. The capabilities of the approach are demonstrated by applying it to the hierarchical design of negative stiffness metamaterials for energy absorption applicationsAdditive manufacturing (AM) is making a profound impact on our ability to realize complex metamaterials and structures, but fully realizing the manufacturing freedom afforded by AM requires some significant advances in engineering design methods and tools. For some additive manufacturing applications, simulation-based design tools may be required to explore a hierarchy of features, ranging in size from microns to meters. At the same time, these tools need to provide real-time feedback on the constraints and process-structure-property relationships relevant to specific AM technologies, and this Design-for-AM feedback is needed during the design process, rather than at the end. To address these challenges, a design exploration approach has been established for creating inverse maps of promising regions of a hierarchical structural/material design space. The approach utilizes machine learning classifiers for identifying sets of promising solutions to a materials design problem, combined with statistical char...

Design and Prototype Development of Portable Trash Collector Boat for Small Stream Application

Commercially available trash collector boats are often designed in large size to cater to the high trash loading for surface water cleaning purpose. On the other hand, for small streams and drainage, the manual cleaning method is often used. This situation is undesirable since it can lead to health problem and diseases to the operator due to the number of impurities present in the water. This paper highlights a proposed design of a trash collecting boat for cleaning purposes in small area applications such as lakes, small streams and drainage. The trash collector boat is designed to be a small and automated boat capable of collecting floating solids off the water surface and store them temporarily. The trash will be manually collected at the end of the operation. The design methodology has been accomplished using engineering design method to propose a suitable design of portable trash collector boat based on commercially available design. With the aid of Autodesk Inventor 2009, a 3D representation of the trash collector boat was generated to visualize all the details regarding the trash collector boat. System fabrication will be conducted using appropriate material to ensure the efficiency of trash collector boat. Testing and analysis were conducted to evaluate the system performance, monitoring unit performance and loading capacity of the portable trash collector boat. The results found that the collector boat is capable of handling a maximum trash load of 6 kg in a single operation.

Models Designed to Increase the Work of Reversible Disc Plough

In this paper, we study the models designed to increase the work of reversible disc plough. Results of research on the use of design-engineering methods of a heightening of serviceability are reduced and it is offered to use an improved disk of digging out device root of the tillage machines. Results of a study on the application of design and technological methods revealed that one of the promising areas of increased efficiency and durability are strengthening blades durable material of variable thickness.

Structural Design and Modelling Method for the Post-tensioned CLT Shear Wall Structures

This paper presents the direct displacement-based design (DDD) procedure, structural modelling method, and structural performance calibration for post-tensioned CLT shear wall structures (PT-CLTstrs). Numerical models of the post-tensioned (PT) CLT shear walls were developed and calibrated with the experimental results. Based on the developed shear wall models, parametric analysis were conducted to investigate the lateral performance influencing factors. Then, a DDD procedure was developed and demonstrated by the design examples of a set of 8-, 12-, and 16-storey PT-CLTStrs. The corresponding simplified structural models were developed, and then a series of pushover and time-history dynamic analysis were conducted to calibrate the calculated structural performance objectives with the design targets of the DDD procedure. Finally, the empirical cumulative distribution functions (CDFs) of the maximum inter-storey drift (MaxISDR) were constructed. It is found that when the width of the PT CLT shear walls increases from 1.8 m to 3.0 m, the base shear at the drift of 2.0 % increases by twice accordingly. When the diameter of the PT strand increases from 15.2 mm to 34.6 mm, the base shear at the drift of 2.0 % increases by up to five times. Additionally, the MaxISDR limitation of the PT-CLTStrs is recommended as 2.2 % under the collapse prevention (CP) hazard level. The study results can serve as guidelines for the development of engineering design methods for the PT-CLTStrs.

Early osteointegration evaluation of porous Ti6Al4V scaffolds designed based on triply periodic minimal surface models

BackgroundThe graded porous structures were designed using triply periodic minimal surfaces models to mimic the biomechanical properties of bone. The mechanical properties and bone formation ability were evaluated to explore the feasibility of the design method in bone tissue engineering. MethodsThe scaffolds were designed using a P-surface with different pore sizes. All materials were fabricated using 3D printing technology and the mechanical properties were tested by an electronic universal testing device. The biomechanical properties were then analyzed by finite element method, while the ontogenesis of the material in vivo was examined by implanting the scaffolds for five weeks in pigs. ResultsAccording to the obtained results, the pore size ranged between 100 μm to about 700 μm and porosity were around 49.54%. The graded porous architectures can decrease the stiffness of implants and reduce the stress shielding effect. In addition, these porous structures can stimulate bone ingrowth and achieve a stable interface between implants and surrounding bone tissues after 5 weeks' implantation. The micro-CT results also demonstrated the obviously bone formation around all the porous structures. ConclusionTo sum up, the triply periodic minimal surfaces based graded porous structure is effective in decreasing the stress shielding effect, promoting early osteogenesis and osteointegration. This is the first research to explore the effect of this kind of porous structures on bone formation in vivo where the obtained results supported the previous theoretical research on the application potential in bone tissue engineering. The translational potential of this articlePorous architecture designed using triply periodic minimal surface models can achieve gradually changed pore size and appropriate porosity for bone regeneration. This kind of structure can mimic the Young’s modulus of natural bone tissue, improve the stress transmission capability and dismiss the stress shielding effect. It also can stimulate the early bone integration in vivo and enhance the binding force between bone and implants, which may bring a new design method for orthopaedic implants and their surface structure.

Effects of the Design Parameters against Slab on Grade Volume Using Corps of Engineering Design Method

Failure of concrete slab construction on the ground such as in warehouse floor, hangar floor, and rigid pavement structure on the highway may result in the inaccuracy of the applied design parameter analysis. The study aimed to analyze the effects of the design parameters of base ground material, concrete material, and vehicle load on slab on grade capacity using design method of Corps of Engineering (COE). The design parameter used vehicle loads of 25 Kips, 50 Kips, 75 kips, 100 kips and 120 Kips, medium quality concrete material of compressive strength concrete fc’ 20 MPa, 25 MPa, and 30 MPa as well as high quality concrete material of compressive strength concrete 35 MPa and soft base ground material (k100 Pci), medium (k 150 Pci), and hard (k 200 Pci). COE method has f(t) variables, namely concrete Modulus of Rupture (flexural strength) of 485 Psi, 542 Psi, 594 Psi, 641 Psi, vehicle axle load of 25 Kips, 50 Kips, 75 Kips, modulus of base ground reaction of k 100 Pci, 150 Pci, and 200 Pci, the number of passing vehicles of 5 million. The making of Taufik Costarico Slab On Grade (TCSOG) Program was carried out by preparing nomogram drawing digitization using autocad program, finding out the equation of lines in the excel program, and finally having it created using visual basic program. With the help of TaufikCostarico slab on grade program, there obtained 60 thicknesses of concrete slab on grade. The result of the study showed that the more the vehicle load was, the thicker the concrete plate would be. In contrast, the harder the base ground was, the thinner the concrete plate had to be. In conclusion, the high concrete quality of fc’ 35 MPa, hard ground of k 200 Pci, and concrete slab on grade thickness of 101.6 mm (4 in) are the same for vehicle loads of 25 kips, 50 kips, 75 kips, 100 kips and 120 kips.

Problems of dependability and possible solutions in the context of unique highly vital systems design

Aim. The paper examines the problems caused by the conventional interpretation of dependability that prevent the practical use of dependability analysis (assessment) as a tool for engineers involved in the creation of unique highly vital systems and substantiates proposals for their resolution. Methods. The paper analyzes the problem of quantitative estimation of the dependability of unique highly vital systems without the use of probability statistical models. The view of dependability as a physical property of a product (as a result of changes in its internal state) allows at the physical level ensuring lasting capability to fulfil the required functions and quantitatively estimating the criteria of the required functions’ performance, that can be defined by, for instance, specifying a set of parameters for each function that characterize the capability to perform, as well as the permissible limits of such parameters’ variation. Such approach causes the requirement to take the origin of dependability into consideration and examine the causes of unlikely failures that are to be identified by means of additional analysis in parallel with calculations and experiments performed to support dependability. The solution to the problems of fuzzy terminology allows revealing the interrelation between the quality and the dependability, thus enabling using the single information basis of design and process engineering solutions the analysis, synthesis and assessment of the dependability of unique highly vital systems based on performance parameters without the use of probabilistic statistical models. Results. The solution of the above dependability-related problems allows ensuring dependability based on the physicality (causal connections) and physical necessity (consistency with the laws of nature) of the causes of failures. The dependability of unique highly vital systems must be ensured from the very early lifecycle stages based on consecutive execution of certain design, process engineering and manufacturing procedures, as well as application of engineering and design analysis of dependability, which also allows solving problems indirectly related to dependability, e.g. improving the quality and reducing the cost of the manufactured products. Conciusions. The paper shows that the application of design engineering methods for the dependability analysis (assessment) allows within the framework of existing views, yet with certain corrections solving dependability-related problems without the use of the mathematics of the classic dependability theory. High dependability can be achieved by the same ways as undependability comes about, i.e. through design and process engineering solutions. The analysis, substantiation of engineering solutions and specification of necessary and sufficient requirements for the manufacturing process allows achieving the target dependability by engineering means through higher quality of design and process engineering. If we regard dependability as a multiparametric property, parametric models of products can be developed that enable the evaluation of the temporal stability of parameter values using methods of individual design dependability and/or design engineering analysis of dependability. The principles of unity of the design concept and its implementation in manufacture enables the development of products and assessment of their dependability based on a single foundation, i.e. the design and process engineering solutions directly associated with the capabilities of a specific manufacturing facility.

Proposal of a user-centred approach for CPS design: pillbox case study

Abstract Product design greatly evolves for years, due to the increasing complexity of products, from simple monodisciplinary products to mechatronics systems then cyber-physical systems. Teams involved in the development of such systems are strongly interdisciplinary and require adequate engineering design methods. We propose hereafter a dedicated design process that integrates systems engineering approach, creativity tools and user-centered design methods. This design process has been implemented within a case study from e-health sector: a home-care provider asked us for developing and experimenting a ‘connected’ pillbox. After detailing main results of this development, we analyze them and propose methodological improvements. We finally conclude on some perspectives for studying engineering design in the context of global e-health systems.

Optimal combination design method of two hydrologic variables based on risk analysis

The joint occurrence of hydrological variables may cause structural failure for a civil hydraulic engineering. However, the large values of these variables are not always occurring together. The assumption of two extreme hydrology events occurring simultaneously is unreasonable and uneconomic in the traditional engineering design method. For better choice of combined variables in design, the combined effect should be considered. So, based on conditional risk probability, a new optimal combination design method of two hydrologic variables was proposed. A case study from Shenzhen using the rainfall and the wind data showed that there was a low joint occurrence probability of high rainfall and high wind speed. For a given design risk probability of 1%, the 24 h rainfall with a design risk threshold of 457.7 mm and a wind speed of 27.4 m/s are the best combination, or the wind speed with a design risk threshold of 30.99 m/s and a 24 h rainfall of 396.5 mm are the best combination. The two best combination conditions should be met simultaneously for effectively improving safety, credibility and economy of a civil hydraulic structure design.

Concept, Theory, Design, and Applications of Spoof Surface Plasmon Polaritons at Microwave Frequencies

AbstractSurface plasmon polaritons (SPPs) are highly localized surface waves that exist on the interface of two media with opposite permittivities at optical frequencies. To produce spoof SPPs at microwave or terahertz frequencies, plasmonic metamaterials have been proposed by making subwavelength structures on a metal surface. Spoof SPPs inherit the properties of natural SPPs, including dispersion characteristics, field confinement, and subwavelength resolution, and therefore are highly expected to offer new solutions for advanced circuits and systems with high integration, compact size, and excellent performance. In this article, the development of spoof SPPs in recent years is reviewed, focusing primarily on the basic concept, theory, design method, and applications in microwave engineering. First, the concept and theory of SPPs and spoof SPPs are introduced, along with development from bulky waveguides to ultrathin transmission lines (TLs) and the unique merits of this new type of TL. Then, the design method is studied, including the feeding strategy of spoof SPP TLs and the realization of reconfigurable spoof SPPs. Recent progress on the engineering realization of plasmonic circuits is also demonstrated, including passive SPP circuits, active SPP devices, and SPP antennas. Finally, the future directions and potential applications of microwave spoof SPPs are discussed.

Multiobjective Optimization Design of a Switched Reluctance Motor for Low-Speed Electric Vehicles With a Taguchi–CSO Algorithm

This paper proposes a novel multiobjective optimization design method for a switched reluctance motor (SRM) on low-speed electric vehicles (EVs). According to the indexes of a low-speed EVs propulsion system and the large torque ripple of the SRM, six objectives of geometric parameters optimization of the SRM are given, which are maximum speed, acceleration time (including in situ acceleration time and overtake acceleration time), maximum climbing gradient, energy usage ratio, and torque ripple factor. The rated parameters of the driving motor are given based on the basic parameters of the low-speed EVs. Based on the engineering design method, the dimension range of the SRM under the rated parameter range is confirmed. The dynamic simulation model of a low-speed pure EVs propulsion system is built in MATLAB/Simulink based on the finite element model of the SRM and the vehicle balance equation. Then, a multiobjective optimization design of the geometric parameters of the SRM is carried out by a Taguchi-chicken swarm optimization algorithm. The correctness of the finite element model is verified, and the accuracy of the multiobjective optimization is verified by the dynamic simulation results and the low-speed EV experiment.

A Multimodal Exploration of Engineering Students' Emotions and Electrodermal Activity in Design Activities

AbstractBackgroundThis exploratory study uses multimodal approaches to explore undergraduate student engagement via topic emotions and electrodermal activity (EDA) in different engineering design method activities and with different instructional delivery formats (e.g., lecture vs. active learning).Purpose/HypothesisThe goal of this research is to improve our understanding of how students respond, via engagement, to their engineering design activities during class. This study hypothesizes that students would experience no self‐reported mean changes in topic emotions from their preassessment scores for each engineering design topic and instructional format nor would electrodermal activities (EDA) associate to these topic emotions throughout the design activities.Design/MethodEighty‐eight freshmen engineering students completed online pretopic and posttopic emotions surveys for five engineering design activities. A subset of 14–18 participants, the focal point of this study, wore an EDA sensor while completing the surveys and participating in these sessions.ResultsPreliminary findings suggest that EDA increased for individual and collaborative active learning activities compared to lectures. No significant changes in EDA were found between individual and collaborative active learning activities. Moderate negative correlations were found between EDA and negative topic emotions in the first engineering design activity but not across the rest. At the end of the semester, active learning activities showed higher effect sizes indicating a re‐enforcement of students' engagement in the engineering design method activities.ConclusionThis study provides initial results showing how multimodal approaches can help researchers understand students' closer‐to‐real‐time engagement in engineering design topics and instructional delivery formats.

A General Methodology for Uncertainty Quantification in Engineering Analyses Using a Credible Probability Box

Uncertainty quantification (UQ) is gaining in maturity and importance in engineering analysis. While historical engineering analysis and design methods have relied heavily on safety factors (SF) with built-in conservatism, modern approaches require detailed assessment of reliability to provide optimized and balanced designs. This paper presents methodologies that support the transition toward this type of approach. Fundamental concepts are described for UQ in general engineering analysis. These include consideration of the sources of uncertainty and their categorization. Of particular importance are the categorization of aleatory and epistemic uncertainties and their separate propagation through an UQ analysis. This familiar concept is referred to here as a “two-dimensional” approach, and it provides for the assessment of both the probability of a predicted occurrence and the credibility in that prediction. Unique to the approach presented here is the adaptation of the concept of a bounding probability box to that of a credible probability box. This requires estimates for probability distributions related to all uncertainties both aleatory and epistemic. The propagation of these distributions through the uncertainty analysis provides for the assessment of probability related to the system response, along with a quantification of credibility in that prediction. Details of a generalized methodology for UQ in this framework are presented, and approaches for interpreting results are described. Illustrative examples are presented.

Parametric design of garment flat based on body dimension

Garment flats have a wide application in product development production and designing stages. However, the traditional drawing methods of garment flat are very time-consuming, and need professional drawing skills. In this paper, a parametric design method was proposed based on body dimension to draw garment flats. The relations among human body, flats and garment show that a garment flat has a close relation with human body and real garment. Graphic analysis shows that a garment flat is constrained by two kinds of parameters: geometric and dimensional parameters. Then, the parametric relation model between garment flat and human body dimensions was constructed. According to the parametric relation model, all the dimensions of a garment flat can be represented by several dimensional parameters and style parameters. Finally, an application program (JFRS, 2016) based on the proposed method was developed to generate garment flats. The result shows that the proposed method is more effective than traditional methods. Moreover, the engineering design methods have been successfully applied to improve design efficiency in artistic design in this research. This is a novel research idea in the field of fashion design, and could be further applied in other design domains.

Towards smart manufacturing process selection in Cyber-Physical Systems

Cyber-Physical Systems (CPS) are becoming increasingly important in manufacturing due to the digitization of the industry driven by advances in technology and connectivity. However, the variation of process selection criteria, both geometric and non-geometric, across the main groups of manufacturing processes, i.e., additive, subtractive, and deformation, makes it difficult to implement smart manufacturing process sequence selection which is an essential step toward achieving an autonomous CPS. This paper presents a conceptual solution to process selection called Constraint Satisfaction Problem for Manufacturing (CSP4M) which leverages current engineering design methods and architectures.

From factor to vector, a quantum transition in assessing safety in ATM systems

Recently, several major events in various high tech industries have revealed deficiencies in assessing safety at a systems level. Conventional analytic approaches in the operational phase suffer from paradigmatic limitations. In non-plus, ultra-safe and complex, dynamic systems, such as Air Traffic Management systems, safety requires a new approach in which:-Safety is a strategic value in decision making and business modeling.-Safety is a system property, represented by state/space vectors.-Safety assessment focuses on quantifiable dissimilarities between various system states and operating conditions throughout their life cycle phases.In order to cope with non-linear interactions and interventions, firstly, safety has to be integrally designed into the system and assessed as an inherent property before it can manifest itself in practice as an emergent property. Secondly, engineering design methods have to be mobilized, such as forensic engineering, value and knowledge based engineering and resilience engineering. The design of safer systems should apply a non-linear design methodology, with an integral assessment of all values and performance requirements, including safety. Such a predictive, quantifiable assessment includes simulation, prototyping and dissimilarity measurements. Finally, system adaptation should focus on the functional level, inherent system properties and synchronization of event vectors and system state vectors.

Application of Microperforated-Panel Absorber in Communication Products

Base on Prof. Maa Dah-You’s general theory of the microperforated-panel (MPP) absorber, We designed a noise reduction structure-sound attenuating cabinet (SAC). It can be applied to air-cooled communication products to reduce system noise. This article introduces engineering design method of SAC and laboratory test noise reduction results of application of SAC.

Vibration responses of glulam beam-and-deck floors

Floor vibration serviceability problems can exist for floors constructed from low mass-to-stiffness engineered-wood products. This paper addresses responses of beam-and-deck floors constructed using glued-laminated-timber (glulam) products. Such floors have widely spaced parallel beams supporting flat wise oriented deck elements and are a relatively new construction option for floors having spans up to about 10 m. The primary focus of discussion here is the experimental investigation of how design variables like span, support arrangement, beam spacing and the addition of non-structural topping materials alter vibration responses of floors. Focus group opinions of acceptability of motions of floors resulting from walking footfall impacts were collected as an indication of the practicality of using engineering design decisions to control vibration of beam-and-deck floors. Collected opinions support the premise that dynamic motions of floors can be controlled in desired ways using practical engineering design methods. However, it was also apparent from the data that suitable methods need to be ones specifically calibrated to suit beam-and-deck floors rather than those applied to other types of low mass-to-stiffness engineered-wood products. No attempt is made to propose new vibration serviceability performances criteria or design methods. This is because it would conflict with ongoing international efforts to create criteria and methods that apply across a wider range of floor construction technologies.