Detailed Design Stage Research Articles

A concurrent optimization model for supplier selection with fuzzy quality loss

Purpose: The purpose of this research is to develop a concurrent supplier selection model to minimize the purchasing cost and fuzzy quality loss considering process capability and assembled product specification.Design/methodology/approach: This research integrates fuzzy quality loss in the model to concurrently solve the decision making in detailed design stage and manufacturing stage.Findings: The resulted model can be used to concurrently select the optimal supplier and determine the tolerance of the components. The model balances the purchasing cost and fuzzy quality loss.Originality/value: An assembled product consists of many components which must be purchased from the suppliers. Fuzzy quality loss is integrated in the supplier selection model to allow the vagueness in final assembly by grouping the assembly into several grades according to the resulted assembly tolerance.

Investigation into Improvement for Anti-Rollover Propensity of SUV

Currently, many research from domestic and foreign on improving anti-rollover performance of vehicle mainly focus on the electronic control of auxiliary equipment, do not make full use of suspension layout to optimize anti-rollover performance of vehicle. This investigation into anti-rollover propensity improvement concentrates on the vehicle parameters greatly influencing on anti-rollover propensity of vehicle. A simulation based on fishhook procedure is used to perform design trials and evaluations aimed at ensuring an optimal balance between vehicle’s design parameters and various engineering capacities, the anti-rollover propensity is optimized at the detailed design stage of a new SUV model. Firstly a four-DOF theoretical kinematic model is established, then a complete multi-body dynamics model built in ADAMS/car based on the whole vehicle parameters is correlated to the objective handing and stability test results of a mule car. Secondly, in fishhook test simulations, the Design of Experiments method is used to quantify the effect of the vehicle parameters on the anti-rollover performance. By means of the simulation, the roll center height of front suspension should be more than 30 mm, that of rear suspension less than 150 mm, and the HCG less than 620 mm for the SUV. The ratio of front to rear suspension roll stiffness should be ranged from 1.4 to 1.6 for the SUV. As a result, at the detailed design stage of product, the anti-rollover performance of vehicle can be improved by optimizing chassis and integrated vehicle parameters.

A reliability-based design framework for early stages of design process

The traditional decision-making process during early design stages deals with deterministically evaluating the design candidates in accordance with concrete objectives by assuming optimal or nominal design performance values for the candidates. However, this may increase subjectivity in the decision process since the design knowledge during early design is usually imprecise and incomplete, and mostly needs to be iteratively updated throughout product design development. To diminish the subjectivity, the knowledge of the design requirements can be precisely and accurately represented by means of probabilistic constraints that describe the uncertainties in the design requirements; therefore, in this work, a systematic design framework supported by reliability analysis is developed in such a way that it is able to provide an effective connection among the early design steps especially both at system level and component level. Thus, the probability of failures of the design candidates and their sub-solutions are investigated, based on design constraints with Gaussian distributions, or lower and upper bounds, by utilizing Monte Carlo method. To illustrate the potential applicability and efficacy of the proposed framework, a two-finger gripper design problem is considered. The results clearly demonstrate that the proposed framework is effective to achieve reliable design solutions that have uncertain quantitative characteristics to be used further in probabilistic structural analysis during the next design stages such as embodiment and detail design stages.

빌딩의 지속가능 에너지환경 분석 및 평가를 위한 기초 연구 : 주거용 건물의 에너지환경 실적정보를 중심으로

최근 건물의 에너지 소비량이 전체 에너지 소비량의 약 20.5%를 차지하면서 건물의 에너지 고효율과 저소비에 대한 관심이 높이지고 있다. 또한 에너지 분석 및 평가에 다양한 연구가 이루어지고 있다. 건물의 초기설계 단계에서 에너지 분석 및 평가를 수행하고 적용할 경우 매우 효과적인 것으로 알려져 있다. 그러나 초기설계 단계에서는 창면적비, 외피면적 등 개괄적인 수준의 정보를 이용하여 에너지성능을 평가하기 때문에 자재 및 설비 등의 상세정보가 포함된 설계를 기준으로 평가하는 실시설계 단계의 결과와 많은 차이를 보일 수밖에 없다. 지금까지 대부분의 연구들은 건물에 설치되는 자재 및 설비 등에 대한 상세정보가 명확해지는 실시설계 단계에서의 분석 및 평가에 관한 것으로 초기설계 단계에서 이들 정보를 보완하는 연구는 미흡하다. 따라서 건물의 생애주기 동안 발생되는 에너지환경 정보를 구축하여 확률/통계적 방법으로 초기설계 단계에서 분석/평가에 정확한 정보를 제공할 수 있다면 에너지환경 분석의 정확성을 향상 시킬 수 있을 것이다. 그러나 아직까지 국내에서 에너지 사용에 대한 실적정보가 구축된 사례가 없다. 따라서 본 연구에서는 에너지환경 실적정보 구축을 위해 에너지환경 분석에 대해 고찰을 수행하고 분석하였다. 그리고 연구의 결과로 건물의 생애주기 정보 구축에 활용할 수 있는 정보분류체계와 정보 개념모델, 그리고 에너지환경 정보의 취득 및 제공을 위한 서비스 개념모델을 제시하여 향후 실적정보 시스템 개발 연구의 기초 자료로 활용하도록 하였다. 본 연구의 결과는 실적정보 지원 관리시스템 구축에 활용되어 초기설계 단계에서 입력정보를 보완하여 분석/평가의 신뢰성을 높일 수 있을 것이다. 만약 실적정보가 구축된다면 초기설계 단계에서 에너지환경 분석 및 평가를 위한 확률/통계 혹은 인공지능 등의 방법에 학습데이터로 활용될 수 있을 것이다. The energy consumption of buildings is approximately 20.5% of the total energy consumption, and the interest in energy efficiency and low consumption of the building is increasing. Several studies have performed energy analysis and evaluation. Energy analysis and evaluation are effective when applied in the initial design phase. In the initial design phase, however, the energy performance is evaluated using general level information, such as glazing area and surface area. Therefore, the evaluation results of the detailed design stage, which is based on the drawings, including detailed information of the materials and facilities, will be different. Thus far, most studies have reported the analysis and evaluation at the detailed design stage, where detailed information about the materials installed in the building becomes clear. Therefore, it is possible to improve the accuracy of the energy environment analysis if the energy environment information generated during the life cycle of the building can be established and accurate information can be provided in the analysis at the initial design stage using a probability / statistical method. On the other hand, historical data on energy use has not been established in Korea. Therefore, this study performed energy environment analysis to construct the energy environment historical data. As a result of the research, information classification system, information model, and service model for acquiring and providing energy environment information that can be used for building lifecycle information of buildings are presented and used as the basic data. The results can be utilized in the historical data management system so that the reliability of analysis can be improved by supplementing the input information at the initial design stage. If the historical data is stacked, it can be used as learning data in methods, such as probability / statistics or artificial intelligence for energy environment analysis in the initial design stage.

Effects of sheds and cemented joints on seismic modelling of cylindrical porcelain electrical equipment in substations

Earthquake resilience of substations is essential for reliable and sustainable service of electrical grids. The majority of substation equipment consists of cylindrical porcelain components, which are vulnerable to earthquake shakings due to the brittleness of porcelain material. Failure of porcelain equipment has been repeatedly observed in recent earthquakes. Hence, proper seismic modelling of porcelain equipment is important for various limit state checks in both product manufacturing stage and detailed substation design stage. Sheds on porcelain core and cemented joint between porcelain component and metal cap have significant effects on the dynamic properties of the equipment, however, such effects have not been adequately parameterized in existing design guidelines. This paper addresses this critical issue by developing a method for taking these two effects into account in seismic modelling based on numerical and analytical approaches. Equations for estimating the effects of sheds and cemented joint on flexural stiffness are derived, respectively, by regression analyses based on the results of 12 pieces of full-scale equipment in 500kV class or higher. The proposed modelling technique has further been validated by shaking table tests.

Fire risk analysis procedure based on temperature approximation for determination of failed area of offshore structure: Living quarters on semi-drilling rig

Fire risk analysis (FRA), one of the dedicated safety studies in offshore risk assessment, aims at determining the potential fire scenarios that threaten the offshore plants and its associated facilities. In the detailed design stage, there is a routine FRA procedure that is conducted to probabilistically determine the safety of the topside structure. This procedure, however, lacks a direct probabilistic risk analysis for determination of the design accidental load (DAL) or of the necessary insulated protection applied to the critical targets on offshore plants. This paper conceptually proposes a quantitative-probabilistic FRA procedure for calculating the design temperature distribution and probable failed areas of critical targets. The proposed procedure considers a full combination of blowout scenarios that can possibly take place on a semi-submersible drilling rig. In scenario identification, the probability distributions of random variables related to fire events are taken into consideration. In consequence analysis, a CFD-based fire simulation (KFX, 2010) in conjunction with a heat transfer analysis (FAHTS, 2010) is carried out to calculate the temperature distribution at the wall surface of living quarters (LQ). In response to the heavy computational CFD simulation, this paper also introduces an approximation method to reduce the time cost of analysis, which depends on the number of input scenarios. Lastly, in risk evaluation, the failed area of LQ is predicted using 2 different risk analysis methods: cumulative failure frequency (CFF) and temperature exceedance curve (TEC).

On the Safety and Performance Demonstration Tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and Validation and Verification of Computational Codes

Abstract The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V&V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodium showed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

Strategy for developing energy systems for remote communities: Insights to best practices and sustainability

Energy planners and policymakers have identified off-grid energy systems as an option for electrifying remote communities around the globe. Such systems could be fueled by either non-renewable or renewable energy resources, but because of the issue of climate change and the compelling need for environmental sustainability, the global community is strongly advocating the use of eco-friendly energy technologies. Renewable energy technologies are therefore deployed for clean energy production, especially in places where there are vast renewable energy resources. However, while there is high optimism about such technologies, there is a lack of knowledge and understanding of the strategies necessary to successfully develop them for off-grid communities. This invariably leads to poor, unreliable and unsustainable systems. This paper introduces enabling strategies for developing energy systems in remote communities, with the aim of achieving sustainability. The planning approaches attempt to integrate the necessary processes and stakeholders during the pre-design, detailed design, implementation and post-implementation stages, with reference to global engineering standards. We present a user-centered approach and also introduce design safety and load growth factors into the energy supply system sizing model for achieving reliable systems. Two different remote communities in Nigeria are used to test the proposed design approaches. The results demonstrate how the issue of a lack of knowledge could be addressed, thus, providing useful approaches for achieving widespread deployment of distributed energy generation projects for isolated communities around the world.

Evaluating the Effect of Minimizing Screws on Stabilization of Symphysis Mandibular Fracture by 3D Finite Element Analysis.

The objective of this work is to integrate structural optimization and reliability concepts into mini-plate fixation strategy used in symphysis mandibular fractures. The structural reliability levels are next estimated when considering a single failure mode and multiple failure modes. A 3-dimensional finite element model is developed in order to evaluate the ability of reducing the negative effect due to the stabilization of the fracture. Topology optimization process is considered in the conceptual design stage to predict possible fixation layouts. In the detailed design stage, suitable mini-plates are selected taking into account the resulting topology and different anatomical considerations. Several muscle forces are considered in order to obtain realistic predictions. Since some muscles can be cut or harmed during the surgery and cannot operate at its maximum capacity, there is a strong motivation to introduce the loading uncertainties in order to obtain reliable designs. The structural reliability is carried out for a single failure mode and multiple failure modes. The different results are validated with a clinical case of a male patient with symphysis fracture. In this case while use of the upper plate fixation with four holes, only two screws were applied to protect adjacent vital structure. This behavior does not affect the stability of the fracture. The proposed strategy to optimize bone plates leads to fewer complications and second surgeries, less patient discomfort, and shorter time of healing.

Integration of multi-objective structural optimization into cementless hip prosthesis design: Improved Austin-Moore model

A new strategy of multi-objective structural optimization is integrated into Austin-Moore prosthesis in order to improve its performance. The new resulting model is so-called Improved Austin-Moore. The topology optimization is considered as a conceptual design stage to sketch several kinds of hollow stems according to the daily loading cases. The shape optimization presents the detailed design stage considering several objectives. Here, A new multiplicative formulation is proposed as a performance scale in order to define the best compromise between several requirements. Numerical applications on 2D and 3D problems are carried out to show the advantages of the proposed model.

Redesign of steam turbine rotor blades and rotor packages – Environmental analysis within systematic eco-design approach

Eco-design of steam turbine blades could be one of the possibilities of decreasing the environmental impact of energy systems based on turbines. The paper investigates the eco-design approach to elaboration of the rotor blades and packages. The purpose is to present the course of eco-design of the rotor blades and the rotor packages taking account of eco-design assumptions, solutions and the concept itself. The following eco-design variants of the rotor blades and the rotor packages are considered: elements of the rotor blades made separately (baseline variant of the rotor blades); elements of the rotor blades made of one piece of material; blades in packages made separately and welded (baseline variant of the rotor packages); packages milled as integral elements. At the stage of detailed design, the Life Cycle Assessment (LCA) is performed in relation to a functional unit – the rotor blades and packages ready for installation in a steam turbine, which is the stage of the turbine. The obtained results indicate that eco-innovative solutions for the turbine blades and packages could be achieved through structural and technological changes. Applying new solutions of the rotor blades may produce the following main benefits: 3.3% lower use of materials, 29.4% decrease in energy consumption at the manufacturing stage, 7.7% decrease in the environmental impact in the life cycle. In relation to the rotor packages, the following main benefits may be achieved: 20.5% lower use of materials, 25.0% decrease in energy consumption at the production stage, 16.2% decrease in the environmental impact in the life cycle.

An Approach to Represent and Communicate Product or System Design Ideas at the Fuzzy-Front End of the Design Process

The primary challenge underscored and dealt with was how to represent the product’s or system’s use environment and processes and to communicate ideas and envisaged use contexts effectively at the fuzzy-front early stages of the design process. The work focused specifically on complex products or systems with physical, software and/or cyber components, and the question was how to represent, e.g., the operations of the product or system and the interactions between the user and the product or system betimes in the period between when an opportunity for a new product or system is first considered, and when the idea is judged to be ready to enter formal development. Several approaches are currently being used to express and to communicate ideas at the conceptualization, embodiment, and detail design stages of the design process, but none of them address the challenge described above. We therefore adapted and extended the abstract prototyping concept to allow for total representation of ideas, as well as of use environments and processes early on. Extended abstract prototyping (Ext-AP) entails using combinations of low and high-fidelity prototyping techniques to create cognitive virtual representations, which represent and help designers to express ideas and use contexts—namely, what complex product or system would be like, and how its users would interact with it. Real-world product development case studies have been used to demonstrate how the Ext-AP technique can be put into practice. One of the main observations from the application case studies is that the Ext-AP technique enabled the subjects to express ideas and use contexts more effectively early on. In addition, the extended abstract prototypes (Ext-APs) offered a low cost, yet effective solution for expressing ideas, representing concepts and using contexts, and allowed the subjects to think divergently, make associations, easily and quickly construct, combine, and evaluate alternatives, and work together on multiple ideas simultaneously.

Design, Fabrication, and Experimental Validation of a Warm Hydroforming Test System

In this study, a hydroforming system was designed, built, and experimentally validated to perform lab-scale warm hydromechanical deep drawing (WHDD) tests and small-scale industrial production with all necessary heating, cooling, control and sealing systems. This manuscript describes the detailed design and fabrication stages of a warm hydroforming test and production system for the first time. In addition, performance of each subsystem is validated through repeated production and/or test runs as well as through part quality measurements. The sealing at high temperatures, the proper insulation and isolation of the press frame from the tooling and synchronized control had to be overcome. Furthermore, in the designed system, the flange area can be heated up to 400 °C using induction heaters in the die and blank holders (BH), whereas the punch can be cooled down to temperatures of around 10 °C. Validation and performance tests were performed to characterize the capacity and limits of the system. As a result of these tests, the fluid pressure, the blank holder force (BHF), the punch position and speed were fine-tuned independent of each other and the desired temperature distribution on the sheet metal was obtained by the heating and cooling systems. Thus, an expanded optimal process window was obtained to enable all or either of increased production/test speed, reduced energy usage and time. Consequently, this study is expected to provide other researchers and manufacturers with a set of design and process guidelines to develop similar systems.

친환경 제품 개발 방법 및 전략 조사

Since eco products need to be developed to better satisfy environmental regulations and customers’ concerns with environmentally friendly products, efforts are needed to establish better eco product development methods and strategies. The present study surveyed methods and strategies of eco product development through literature review and organized them based on the ISO TR 14062 eco product development process. The selected 20 papers (6 methods; 12 strategies; 2 methods and strategies) can be applied to each stage of the TR 14062 eco product development process as follows: 14 papers related to planning stage, 3 papers related to conceptual design stage, and 6 papers related to detailed design stage. The eco product development methods and strategies surveyed in this study can be used to identify considerations at each stage of eco product development process and analyzing features of products effectively.

Two- and three-dimensional springing analysis of a 16,000 TEU container ship in regular waves

In recent years, the increase in world trade has resulted in a large expansion of sea traffic. As a result, market demands are leading to the development of Ultra Large Container Ships (ULCSs), with lengths of up to 400 m and increased flexibility of operational requirements. The multicellular open-decked thin-walled structural design of these ships means that flexible hull girder dynamics become important for the prediction of wave loads. This paper investigates the importance of various hydroelastic modelling approaches on the global symmetric and anti-symmetric response of a 16,000 twenty-foot equivalent unit (TEU) ULCS design. Two- and three-dimensional linear and weakly non-linear flexible fluid–structure interaction models that respectively combine Vlasov beam and three-dimensional finite element analysis (FEA) structural dynamics with a B-spline Rankine panel and Green's function hydrodynamics are assessed and compared. Comparisons between rigid body and hydroelastic predictions demonstrate the importance of considering the effects of hull flexibility on the dynamic response and the suitability of different idealisations at preliminary or detailed design stages.

Pattern load analyses for irregular floor systems

It is commonly accepted that pattern load effects are important considerations for the structural design of flooring systems. However, most currently available guidelines are primarily proposed for conventional regular continuous beams and slabs with orthogonal grids, which may often be unclear when applied to more general situations. Derived from the influence line concept, and with simple yet rigorous mathematics, an accurate, simple, robust, well-defined and computationally efficient alternative approach is presented in this paper for pattern load analyses of arbitrary multiple-way spanning floor systems. Designed to work seamlessly with existing commercial finite-element analysis packages, the proposed alternative method provides more realistic estimations of the design load on structural members, and is proved to be practical for daily design practices. It also minimises the need for engineering judgement in the analyses, which will help the future development of computerised automation and optimisation of structural designs to be applicable to the detail design stage.

A new methodology for the synthesis of an optimum flexible water networks

This paper presents a new optimization model for the synthesis of direct reuse/recycle water networks with data uncertainties. In this case, data uncertainties were originated from the varying parameters of the water sources and sinks, which fluctuate within a given range of values. The aim of the method is to design an optimum flexible water network (FWN) that ensures minimum fresh water consumption and yet fulfilling all process constraints and uncertain parameters. The resulting FWN also features the minimum number of pipelines, which will ease process operation and control. Due to the complexity of the problem, multistep solving method based on theorem of corner points has been developed. The FWN obtained using the proposed method also includes information on the maximum flow rate in the pipelines, which is essential for detailed network design stage. The resulting model is a mixed integer linear problem (MILP), which may be solved to obtain global optimum solution. Two case studies were used to elucidate the newly proposed method.

Studying Sea Waterway System with the Aid of Computer Simulation Methods

Abstract The article presents a systematic approach to studying sea waterways. Relations between the parameters of sea waterway system elements and the conditions of safe ship operation are determined. Principles of formulation of the simulation experiment research process in the sea waterway system design process at the preliminary and detailed design stages are defined.

Software Architecture and Detailed Design Evaluation

Software design and estimation play the key role for software development process. Different methods are used for architecture design and detailed design evaluation. For architectural design stage a technique that allows selecting and evaluating suite of architectural patterns is proposed. It allows us to consistently evaluate the impact of specific patterns to software characteristics with a given functionality. Also the criterion of efficiency metric is proposed which helps us to evaluate architectural patterns for specified software. During detailed design stage we are interested in the selection of the optimal metric suits which takes into account the characteristics of required system. The proposed technique contains a number a steps where at each step a specific criterion should be used to make a selection from the available metric suites. In the end we can perform the selected metric suite improvement.

Optimal geometric tolerance design framework for rigid parts with assembly function requirements using evolutionary algorithms

Tolerance design is always a challenging task for engineers, since it need to satisfy multidisciplinary functions. Engineering design is done in two stages: assembly design and detail design. In the first stage, an assembly is designed considering certain system level functions and in secondary detail design stage; decomposition of the assembly is done and process tolerancing is employed for the parts. At the secondary detail design stage, designer adopts geometrical dimensioning and tolerancing (GDT (2) GD&T is adopted in the secondary stage, which is not available in primary stage. This paper offers a framework for a design engineer to bridge the gap and to establish the relation between these stages. A nonlinear combinatorial optimization problem is framed based on assembly function requirement (AFR), and tolerance values are optimized with appropriate constraints. Nontraditional Elitist Non-dominated Sorting Genetic Algorithm (NSGA-II) and differential evolution (DE) algorithms are used to solve the problem. For the allocated position tolerances, appropriate sensitive factors are indicated to facilitate design improvement. Finally, a case study is used to illustrate the complete framework.