Conceptual Design Stage Research Articles

An intelligent body frame structure modeling and optimization system based on conceptual design

The conceptual design stage is an indispensable and important stage in the development of the modern body. However, due to the lack of sufficient body structure parameter support, the design defects generated at this time are difficult to make up for in the subsequent design stage. Therefore, it is of great significance to develop a conceptual design software for body structure that integrates design, analysis, and optimization. This paper proposes an intelligent body frame structure modeling and optimization system based on conceptual design, S-iVCD (Intelligent System for Conceptual Design of Vehicle Body Structure). Based on deep learning methods and body design sketches, a conceptual model of body structure is quickly established. Based on the data parameters stored in the Excel table, the system is seamlessly connected to the domestic independent finite element software SIPESC to calculate the simulated working conditions. The body structure optimization module is driven by the MMA (method of moving asymptotes), and takes the body structure performance and total mass as the optimization goals or constraints of the mathematical model to achieve body structure performance improvement and lightweight design.

Prediction of Ship Main Particulars for Harbor Tugboats Using a Bayesian Network Model and Non-Linear Regression

Determining the key characteristics of a ship during the concept and preliminary design phases is a critical and intricate process. In this study, we propose an alternative to traditional empirical methods by introducing a model to estimate the main particulars of diesel-powered Z-Drive harbor tugboats. This prediction is performed to determine the main particulars of tugboats: length, beam, draft, and power concerning the required service speed and bollard pull values, employing Bayesian network and non-linear regression methods. We utilized a dataset comprising 476 samples from 68 distinct diesel-powered Z-Drive harbor tugboat series to construct this model. The case study results demonstrate that the established model accurately predicts the main parameters of a tugboat with the obtained average of mean absolute percentage error values; 6.574% for the Bayesian network and 5.795%, 9.955% for non-linear regression methods. This model, therefore, proves to be a practical and valuable tool for ship designers in determining the main particulars of ships during the concept design stage by reducing revision return possibilities in further stages of ship design.

A life cycle decision framework of China offshore wind turbines with ANP-Intuitionistic fuzzy TOPSIS method

In China, offshore wind energy is a popular source of green energy. Selecting offshore wind turbine design schemes is a decision problem based on multiple criteria. However, the selection is hardly made from the point of view of the life cycle due to the complex association of evaluation criteria, especially in the conceptual design stage. To solve this problem, a new multi-criteria decision-making framework for selecting the life cycle design scheme of offshore wind turbines is designed. The design information of the life cycle process of these turbines is expressed using Function-Structure-Material-Process-Transportation model in this framework. The life cycle evaluation index system of offshore wind turbines was established and mapped with this model to carry out rapid evaluation of various schemes. In light of this, an intuitive fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method based on analytic network process (ANP) was proposed to process fuzzy decision information and establish criteria correlation. Finally, a case study was conducted, and sensitivity and comparative analyses were carried out. The proposed method can effectively select the optimal scheme from six different design schemes for the life cycle of offshore wind turbines.

Simulation of an aircraft thermal management system based on vapor cycle response surface model

The modern aircraft Thermal Management System (TMS) faces significant challenges due to increasing thermal loads and limited heat dissipation pathways. To optimize TMS during the conceptual design stage, the development of a modeling and simulation tool is crucial. In this study, a TMS simulation model library was created using MATLAB/SIMULINK. To simplify the complexity of the Vapor Cycle System (VCS) model, a Response Surface Model (RSM) was constructed using the Monte Carlo method and validated through simulation experiments. Taking the F-22 fighter TMS as an example, a thermal dynamic simulation model was constructed to analyze the variation of thermal response parameters in key subsystems and elucidate their coupling relationships. Furthermore, the impact of total fuel flow and ram air flow on the TMS was investigated. The findings demonstrate the existence of an optimal total fuel flow that achieves a balance between maximizing fuel heat sink utilization and minimizing bleed air demand. The adaptive distribution of fuel and ram air flow was found to enhance aircraft thermal management performance. This study contributes to improving modeling efficiency and enhancing the understanding of the thermal dynamic characteristics of TMS, thereby facilitating further optimization in aircraft TMS design.

The Optimization of Automobile Part Product Development Using Integrated Product Development (IPD)

This paper studies a new integrated product development (IPD) process at an automobile parts company. The process includes benchmarking and offers four optimization strategies for the new product development process: (1) re-structuring the new product development organization astraddle department teams, (2) reshaping the new product development and selection process already at the planning and conceptual design stages, (3) optimizing the design review process at the engineering stage, and (4) establishing a product development team with large project manager responsibilities in the industrialization stage so as to give full play to the guiding role of expert resources. This paper can help enhance the competitiveness of domestic auto parts enterprises compared to leading foreign auto parts enterprises.

Enhanced Soft Error Rate Estimation Technique for Aerospace Electronics Safety Design via Emulation Fault Injection

In this paper, we propose Automatic Configuration Memory Fault Injection (ACMFI), a tool that calculates the architectural vulnerability factor (AVF) and soft error rate (SER) using the emulation fault injection technique. SER, which is essential for the safety design of aerospace electronics, can be obtained by experiments (beam tests) performed in a beam facility equipped with high-energy radiation facilities. However, SER calculation using beam tests has the disadvantage of a high cost and a long waiting time, making it difficult to use in the conceptual design stage, which is the aerospace system development stage and the initial HW/SW development stage. Using the emulation fault injection method, it is possible to estimate the SER, which can be used in the system safety design phase. This paper describes the ACMFI tool, which automatically performs emulation fault injection in SRAM-based FPGAs, which are widely used in aerospace electronic hardware. Unlike the existing methods, the proposed method has the advantage of minimizing the side effects by injecting faults into a dedicated SRAM area. In other words, the SER obtained by the proposed method can be estimated more accurately than the SER result obtained by the existing method. To prove the accuracy of the proposed test method, the SER calculated by performing an emulation fault injection test on the same FPGA was compared with the SER results tested at the beam facility. The method of obtaining SER using the proposed ACMFI gave results that were closer to the SER obtained by testing at the beam facility than the method of obtaining SER using the existing EMFI. The proposed method is used to calculate the failure rate, which is a key variable in determining the development assurance level when performing safety design tests in aerospace system development, enabling the development of safer systems and lower cost/higher quality aerospace electronic equipment than before.

Formulation of justifiable wind loading distributions up tall buildings derived from HFFB measurements

For the general case of non-linear and combined sway and twist mode shapes, analysis of HFFB measurements gives rise to serious challenges and various techniques have been developed using significant assumptions. This is because it is not possible to directly obtain the distribution of varying fluctuating wind loads throughout the height of tall buildings. This paper proposes a straightforward HFFB-based wind load/twist distribution approach in the time domain to predict the wind-induced dynamic response of tall buildings. Using this framework, it is possible to overcome the deficiencies of mode shape correction factor approach, and the complexity and impracticality of alternative approaches for tall buildings. Two 1:300 scale rigid models of benchmark tall buildings, IAWE Buildings A and B, have been selected to perform a detailed wind tunnel investigation as subjects to evaluate this proposed HFFB approach study. Building A has complex 3D mode shapes combining sway and twist, whereas the simpler Building B has uncoupled linear mode shapes in sway and twist. The high frequency pressure integration (HFPI) wind tunnel technique was utilised to measure surface pressure information in separate tests to obtain the reference wind loading for validation of the HFFB predictions. Furthermore, a commonly used HFFB mode shape correction factor approach was used to estimate the dynamic wind responses which were compared to those from the proposed approach. From the comparison between the aerodynamic and dynamic wind results from proposed HFFB approach and reference HFPI results, it is found that the proposed HFFB approach can predict the vertical distributions of the wind forces and torque (wind loads) with acceptable accuracy for carrying out the conceptual stage of tall building design.

Energy inclusiveness intensity among persons with disability: Evidence from an emerging crude oil producing country

Although Ghana has made great strides in ensuring that its citizens have access to energy, evidence of the inclusion of people with disabilities in policy contexts offers a chance to examine other crucial but less well-known factors that influence energy accessibility. Due to this, a thorough search and scoping evaluation of energy policies/reports from the websites of the Ghanaian government and other relevant sources was carried out. The Energy Policies/reports were chosen and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria for scoping reviews. The framework for policy assessment and policy creation was used for the content analysis. The analysis included seven policies and reports with a total of 13 indicators. Although different institutions and organizations worked together to establish and implement these policies and reports, the level of inclusion of Persons with Disabilities (PWDs) and issues linked to them was relatively low. Only one of the seven (14%) policies/reports examined took PWDs into account. This was due to a limited definition of disability, which shows a low level of inclusion. It is advised that ensuing energy policies/reports should incorporate extensive involvement and participation of PWDs from the conceptual design stage through to implementation to achieve the Sustainable Development Goal (SDG) 7, the United Nations Convention on the Right of Persons with Disabilities, and the Disability Act 715 of Ghana.

Conceptual design vulnerability assessment of the housing light roofs to strong winds

Hurricanes are one of the most significant causes of human and material losses in the Caribbean region. These events have demonstrated their devastating impact on housing and infrastructure. The assessment of the vulnerability of buildings with light roofs, at the initial design stage, is considered to be a fundamental step in the mitigation of these damages and losses. This paper presents the introduction of an indicator-based vulnerability assessment in an effort to mitigate these damages in advance. This indicator facilitates the design team's decision to select the appropriate light roof alternative subject to strong winds at the conceptual stage of the process. The indicators that contribute to the conceptual assessment of vulnerability were identified based on a comprehensive review of the literature and numerical simulations of the risk scenarios using CFD/FEM software’s. The ranking of indicator weights was determined by the Kano method according to experts' opinions. A desktop application has been developed for the assessment of the vulnerability of light roof variants for buildings at the conceptual design stage. The results reported in a case study demonstrate the viability of the desktop application based on the vulnerability indicator to assist decision making in the conceptual design stage.

Designing and constructing of a laboratory scale concrete roof tile dryer

There are some problems with the drying process in the concrete tiles local industry, especially due to uncertain weather, where the drying process relies on sunlight. In addition, roof tile dryers have not yet hit the market. A laboratory-scale dryer is needed to develop a full-scale concrete roof tile dryer. This research aims to design and manufacture a laboratory-scale concrete tile dryer. The dryer will be used to investigate the characteristics of the concrete roof drying. The design was carried out using the Pahl and Beitz method, in three stages, namely planning, conceptual design, and detailed design. In the planning stage, a requirement list was stated, in the conceptual design stage, selected tools are determined for every sub-function, while in the detail design stage, shop drawings were produced. To produce a better distribution of air velocity and temperature, at this detailed design stage, a Solidworks CFD numerical analysis was used. The dimension of the drier is 1600 x 1100 x 1100 mm³, with a capacity of 60 - 180 kg, with air velocity of 3 m/s and variable temperature. The drying chamber consists of 3 layers. The heat source is LPG flame and electric heater. The fresh air is flown to the LPG burner, through a circulating fan into the drying chamber, where the concrete roof tiles are situated. The roof tile dryer was constructed and tested. The test results show that the air velocity at the top layer accorded with the CFD result, while in the second layer and third layer of the drying chamber, the air velocity was relatively small. The temperature in each layer of the drying chamber shows the same value, in this case, the temperature for each layer is 38°C, while the set point at the thermostat was 40°C. The relative humidity of the drying air was 21.7% while the ambient air relative humidity was 52%.

A Building Information Modeling-Life Cycle Cost Analysis Integrated Model to Enhance Decisions Related to the Selection of Construction Methods at the Conceptual Design Stage of Buildings

A Building Information Modeling-Life Cycle Cost Analysis Integrated Model to Enhance Decisions Related to the Selection of Construction Methods at the Conceptual Design Stage of Buildings

Understanding the fixed pitch RPM-controlled rotor modeling for the conceptual design of UAM vehicles

AbstractMost of the introduced eVTOL models in the UAM market utilize electrically driven rotors with fixed pitch blades, controlled by their rotational speed. This design approach brings new features and challenges that need to be considered during the conceptual design stage, taking new aspects into account, among them the rotor dynamic response. This paper presents an initial parameterization of the rpm-controlled rotors along with the electric motor, based on the conducted literature research. Several isolated rotor variants are modeled and analyzed in terms of performance, and the dynamic response of the rotor rotational speed. The relations between aerodynamics and inertia are discussed, and their effects on the rotor dynamic response are elaborated on.

DESAIN KONSEP PURWARUPA MESIN INJECTION MOLDING TIPE VERTIKAL UNTUK DAUR ULANG LIMBAH PLASTIK SKALA RUMAH TANGGA

Plastic waste is the main cause of environmental pollution. It is necessary to research the design of the Injection Molding machine to process plastic waste. This study describes the design concept of a vertical type Injection Molding machine prototype by considering the factors to be utilized by small-scale plastic recycling businesses. The design stage starts from the identification of component requirements to the design of 3D drawings. The results of this study obtained a prototype design of a Vertical Injection Molding Machine. The embodiment of the design is not only determined directly by the design team and the manufacturing team, but is obtained from customer requests described in the technical specifications. At the concept design stage, there are 5 sub-functions and each function has 3 to 4 options. From the combination of these sub-functions and options, 3 assembly sketches were obtained so that 3 alternative design concepts were obtained. From the results of the concept assessment, design concept C was chosen from several alternative concepts.

An integrated computational method for calculating dynamic thermal bridges of building facades in tropical countries

Identifying thermal bridges on building façades has been a great challenge for architects, especially during the conceptual design stage. This is not only due to the complexity of parameters when calculating thermal bridges, but also lack of feature integration between building energy simulation (BES) tools and the actual building conditions. For example, existing BES tools predominantly calculate thermal bridges only in steady state without considering the temperature dynamic behaviour of building outdoors. Consequently, relevant features such as thermal delay, decrement factor, and operative temperature are often neglected, and this can lead to miscalculation of energy consumption. This study then proposes an integrated method to calculate dynamic thermal bridges under transient conditions by incorporating field observations and computational simulations of thermal bridges. More specifically, the proposed method employs several measurement tools such as HOBO data logger to record the actual conditions of indoor and outdoor room temperature and thermal cameras to identify the surface temperature of selected building junctions. The actual datasets are then integrated with the simulation workflow developed in BES tools. This study ultimately enables architects not only to identify potential thermal bridges on existing building façades but also to support material and geometric exploration in early design phase.

CONCEPTUAL DESIGN OF THE SPACE INDUSTRIAL PLATFORM. PROBLEM STATEMENT

The objective of thispaper is to formulate a complex problem of optimizing the design parameters of a space industrial platform at the conceptual design stage. The initial stage of space industrialization was the creation of space industrial platforms in Earth orbit. At present, there are works related to the implementation of a number of technological processes in outer space, which are being studied by scientists and developers. Implementation of unique technological processes in outer space allows forobtaining materials with qualita- tively new characteristics. The peculiarity of designing a space industrial platform is that there are practically no theoretical works related to the choice of platform parameters and the logic of its creation at the conceptual design stage. This stage is characterized by the fact that, apart from the general idea of the platform layout, the expected types of main service systems, some initial data, and the param- eters of the technological processes to be implemented on the p latform, there is little else known. The process of designing a new complex space system, such as an industrial platform, is a multi-level iterative and optimization process, during which its characteristics and mass production are determined and refined. The article analyzes the configurations of existing orbital stations as a prototype of space industrial platforms and determines the ranges of the main parameters of their modules. A set of parameters of technological processes in vacuum and zero gravity conditions that can be implemented on a space industrial platform is formed. The relationship between the technological and basic modules of the industrial platform is shown. The structure of a complex mathematical model of the space industrial plat- form functioning is developed. To ensure successful work at the conceptual design stage, a general statement of the problem of optimizing the mass of the space industrial platform is formulated. The minimum mass and dimensions of the space platform obtained as a result of the optimization are used to further refine the optimal parameters of the platform and, therefore, affect the formation of conditions for the implementation of the technological process. The algorithm of the sequence of operations for solving the problem of optimal design of a space industrial platform is shown in general.

Development of stealth design systems for advanced submarine hull forms to reduce underwater radiated noise and target strength

The stealth capability of a submarine is the key performance to be considered in submarine design since it is directly related to survivability and operational capability. In this study, a system that can be applied from the conceptual design stage for the submarine shape, including the hull forms and appendages, has been developed by considering the two key components that determine the stealth capability of underwater vessels: underwater radiated noise (URN) and target strength (TS). First, for submarine stealth design considering URN, a design optimization technique was developed that can reduce the high flow noise caused by the interaction between the propeller and the vortex generated in various parts of the hull and appendages. And for submarine stealth design considering TS, shape design technology that can minimize the reflections of active sonar was developed through an evaluation method with high adaptability to shape modifications. Finally, by developing the optimization design procedures that comprehensively cover URN and TS, the optimal shapes and arrangements of sail and rudders that can maximize stealth performance have been derived.

Towards composite suspension control arm: Conceptual design, structural analysis, laminate optimization, manufacturing, and experimental testing

The automotive industry needs composite materials to decrease the weight of new-generation vehicles whilst increasing their strength. In this study, one of the critical (load bearing) components of automobiles, i.e., the suspension control arm made of steel, is fully redesigned for its suitable manufacturing using composite materials. To this end, innovative mechanical simulation methods are developed and coupled to perform the design, analysis, and optimization of the automotive suspension control arm. The main design/optimization criteria are set to reduce no less than 75% weight of the metal control arm and increase its safety by at least 60% by using composite materials and a new geometry suitable for mass production. To predict the deformation-stress state of the control arm, a four-node quadrilateral shell element is implemented based on the kinematics of refined zigzag theory (RZT). Once verified numerically, the computer implementation of the RZT is combined with the optimization algorithm to achieve the optimum laminate stacking sequence of the control arm. Accordingly, prototypes of the composite control arms with optimum lamination plans are manufactured and then experimentally tested under the loading and constraint conditions defined at the conceptual design stage. The numerical and full-scale experimental results are compared, and the RZT models are comprehensively validated. Hence, the advantages of the overarching design-analysis-optimization strategy presented herein are revealed for redesigning and manufacturing automobile parts from composite materials.

How does conceptual design impact the cost and carbon footprint of structures?

Making sustainable conceptual design decisions is the key to reduce the environmental impact of the construction industry. Such early decisions, which must be given in a short timeframe, have the largest impact on a project’s quality, cost and embodied carbon. This study showed how much the conceptual design decisions affect the cost and carbon footprint of a building’s structure using our Non-dominated Sorted Genetic Algorithm II tool. First, we tested the tool’s reliability by comparing its solutions with three case studies from literature. Then, we showed that by quickly examining various conceptual design solutions on a Pareto graph (which spotlights cost and CO2-optimized options), more sustainable design alternatives can be identified. Then, using the tool, we analyzed 36 buildingconfigurations, providing a spectrum of embodied carbon emissions (including the life cycle assessment steps A1, A2, A3, A4, A5, C2, C3, C4) ranging between 60 and 360kgCO2e/m2. By comparing 25 material types from 15 databases (EPDs and ICE), we concluded that the geometry decisions (span length, height and shape) have the largest influence, material type (steel, timber, reinforced concrete), recycling and reuse of steel are crucial, and the embodied carbon calculations are highly sensitive to the supplier data and location. Overall, this study showed that architects and engineers possess the ability to significantly reduce the embodied carbon of structural systems by selecting the appropriate materials and structural system at the conceptual design stage.

Research on the influence of organizational form of inspirational information in conceptual design: Workload and creativity

The relationship between information organization and innovation behavior is an important area of study, yet research on the behavior of designers in this regard is underexplored. This study experimentally compared the effects of two forms of inspirational information organization, single-organization (using folders only) and multi-organization (folders plus tags), on designers’ design creativity in the conceptual design stage. The main findings are: (1) The use of tags in the multi-organization form facilitates a more in-depth and involved processing of inspiration information, and significantly improves the effort score. In addition, it reduces the mental and temporal demands in the retrieval process and does not add too much workload to the subjects. (2) Information organization methods have different impacts on creativity. The results show that by using a multi-organization method, the novelty of design solutions can be improved. This study verifies the positive impact of multiple organizations as an inspirational information structuring method on design creativity, which provides a directional reference for the development activities of information organization tools for designers.

Neutronic-thermalhydraulic coupling analysis of heat pipe failure accidents of a new type of megawatt heat pipe reactor

Heat pipe cooled reactors featured with high energy density, long lifecycle, modularity, and compact structure could be ideal power sources for large unmanned undersea vehicles (UUVs). In the early stage of reactor concept design, heat pipe failure accident is usually one of the design basis accidents that need to be considered. In this study, a set of transient analysis models for heat pipe failure accidents of a new type of megawatt heat pipe reactor is established. The models include the point kinetics model, Core Matrix module and Fuel-Heat Pipe module heat conduction models, and radiation heat transfer model for the inner core cavity. 2D-3D combined method is used to solve the heat conduction model in the Fuel-Heat Pipe module. Based on the models, a transient analysis code for heat pipe failure accidents is developed using FORTRAN. The models are separately validated based on the analytical solutions, the experimental data or the CFD results by FLUENT. Neutronic-thermalhydraulic coupling calculation is conducted in normal operation condition and heat pipe failure accidents. The peak temperatures of each region are below their melting points in all presumed heat pipe failure accidents which reflects the good inherent safety of the core. Meanwhile, the calculation results by the code are in good agreement with those of FLUENT, and the maximum relative error of the peak temperature does not exceed 1.5%. The code calculation time is 1/8 of FLUENT ensuring the accuracy of important parameters, effectively reducing the computation costs and improving the computation efficiency. The code also provides a basis for subsequent transient operation condition and typical accidents analysis of this reactor.