Uncertainty based aircraft derivative design for requirement changes

2016 ◽  
Vol 120 (1224) ◽  
pp. 375-389 ◽  
Author(s):  
H.-U. Park ◽  
J. Chung ◽  
D. Neufeld

ABSTRACTAircraft manufacturers often consider producing multiple derivatives of aircraft to satisfy various market demands and technical changes while keeping development costs and time to a minimum. Many approaches have been proposed for carrying out derivative design. However, these approaches consider both the baseline design and derivatives together at the conceptual design stage using the entire set of design variables with an assumed set of expected requirements. These frozen requirements on derivative design cannot consider new demands from market changes. In this paper, a method is proposed that uses design optimisation for conceptual design of derivatives for existing aircraft that consider requirement changes. Furthermore, the Possibility-Based Design Optimisation (PBDO) method was implemented to consider uncertainty in the aircraft operation phase. The altitude range of aircraft operation was defined as an uncertain parameter to prevent violation of constraints in the entire operating envelope of the aircraft. The PBDO method yields a more conservative design than those obtained with deterministic design optimisation.In this paper, the proposed derivative design process was applied to the Expedition 350, a small piston engine powered aircraft produced by Found Aircraft, Canada. A derivative that changes the normally aspirated engine to a turbocharged engine for high-altitude operation was considered. An optimum configuration with the new engine was obtained while enhancing performance and stability characteristics. The proposed derivative design process can be implemented on the derivative design of other aircraft.

2006 ◽  
Vol 34 (3) ◽  
pp. 170-194 ◽  
Author(s):  
M. Koishi ◽  
Z. Shida

Abstract Since tires carry out many functions and many of them have tradeoffs, it is important to find the combination of design variables that satisfy well-balanced performance in conceptual design stage. To find a good design of tires is to solve the multi-objective design problems, i.e., inverse problems. However, due to the lack of suitable solution techniques, such problems are converted into a single-objective optimization problem before being solved. Therefore, it is difficult to find the Pareto solutions of multi-objective design problems of tires. Recently, multi-objective evolutionary algorithms have become popular in many fields to find the Pareto solutions. In this paper, we propose a design procedure to solve multi-objective design problems as the comprehensive solver of inverse problems. At first, a multi-objective genetic algorithm (MOGA) is employed to find the Pareto solutions of tire performance, which are in multi-dimensional space of objective functions. Response surface method is also used to evaluate objective functions in the optimization process and can reduce CPU time dramatically. In addition, a self-organizing map (SOM) proposed by Kohonen is used to map Pareto solutions from high-dimensional objective space onto two-dimensional space. Using SOM, design engineers see easily the Pareto solutions of tire performance and can find suitable design plans. The SOM can be considered as an inverse function that defines the relation between Pareto solutions and design variables. To demonstrate the procedure, tire tread design is conducted. The objective of design is to improve uneven wear and wear life for both the front tire and the rear tire of a passenger car. Wear performance is evaluated by finite element analysis (FEA). Response surface is obtained by the design of experiments and FEA. Using both MOGA and SOM, we obtain a map of Pareto solutions. We can find suitable design plans that satisfy well-balanced performance on the map called “multi-performance map.” It helps tire design engineers to make their decision in conceptual design stage.


Author(s):  
Manish Verma ◽  
Hui Dong ◽  
William H. Wood

Design for Manufacture (DfM) tends to explore only a small space of possible designs toward improving manufacturability. By focusing primarily on detailed geometry, DfM tends to recommend incremental changes. This paper presents a methodology that begins at the conceptual design stage, applying functional modeling to the generation of design configurations. These functional abstractions are merged with real part geometry toward generating potentially manufacturable design skeletons. The direct connection from function to manufacturable form afforded by this method allows the designer to make better-informed design decisions at the earliest stages of the design process.


Author(s):  
Yu-Xin Wang ◽  
Yu-Tong Li ◽  
Jian-Wei Wang

This paper presents a novel indirect matching approach between the function layer and the form layer to enhance the capability for the FBS method to obtain the creative conceptual design results. Firstly, the basic operation actions set, which is composed of the basic operation actions obtained by decomposing each function in the lowest level of the function decomposition tree in the FBS model into the sub-functions, in the function layer is regrouped dynamically. This behavior regroup process has introduced the new design variables into the conceptual design process and leads the behavior creativity to produce. On the other hand, considering the multi-functions for each basic structure to have and representing these functions with the basic operation actions, then the basic operation actions set in the form layer is set up. Dynamic regrouping this set in the form layer, the new design variables has been introduced into the conceptual design process, and leads the form creativity to produce. Through the above behavior-form double directions creative process, the solution scope of the conceptual design is enlarged obviously. Therefore, the method present in this paper has enough capability to obtain the creative conceptual results. Furthermore, the model presented in this paper is represented with the quotient space mathematically. The case study has shown that in the function layer, through adjusting the attribute function, which determines the partition grain of the basic operation actions set in the function layer or in the form layer, the new behaviors can be generated.


Author(s):  
Rong-Yuan Jou

A freezing chucker is a clamp-less mechanism of fixture for easy broken egg-shell, clay, and other ferrous/nonferrous materials. Typical structure of this mechanism includes a top plate for freezing workpieces, a body with specially designed channels for the coolant flows, and a bottom plate to fasten on the table of other machine. Just by a small amount of liquids on the top surface and by rapidly cool down to 253K, parts can be frozen stationary on the top plate surface and can conduct precision machining on it. There are four steps to design a new freeze chucker by the engineering design process: planning and clarifying the task; conceptual design; embodiment design; detailed design. Some useful tools from the Quality Function Deployment (QFD) technique and the Theory of Inventive Problem Solving (TRIZ) method are used in this design process. Eight concept designs are generated by the conceptual design work and the final design of channel with transverse ribs is selected by decision matrix technique during embodiment design and detailed design stage. This final design is evaluated by numerical modeling of the COMSOL MULTIPHYSICS 3.2 finite-element based package. Performances such as the temperature distribution of top-plate surface temperature and the lowest temperature of a freezing chucker are shown. Numerical results show the success of the innovative channel design by this inventive design process using TRIZ methodology.


2015 ◽  
Vol 15 (1) ◽  
pp. 24-41 ◽  
Author(s):  
Sepehr Abrishami ◽  
Jack Goulding ◽  
Farzad Pour Rahimian ◽  
Abdul Ganah

Purpose – The purpose of this paper is to find optimal solutions for conceptual design automation, which can be integrated with Building Information Modelling (BIM) support for construction automation. Problems relating ostensibly to failures in computational support for the conceptual design stage are well-documented in extant literature. These failures are multifarious and significant, with several deficiencies being acknowledged in the Architecture, Engineering, and Construction (AEC) industry. Whilst acknowledging this, extant literature has highlighted the importance of computational design in the AEC industry; and failures in this area include the need to strengthen the congruent links and support mechanisms in order to exploit the opportunities presented by new computational design methods. Given this, it is postulated that the application of generative design could enhance the design experience by assisting designers with the iterative generation of alternatives and parameterisation (change management) processes. Moreover, as BIM applications are increasingly providing comprehensive support for modelling and management, then additional synergies could be examined for further exploitation. Design/methodology/approach – This paper focusses on the potential for developing an interactive BIM environment that purposefully adopts generative design as a method of computational design for the early design stages. This research facilitates the automation of the conceptual architectural design process, using BIM as the central conduit for enhancing the integration of the whole building design process (including design interfaces). This approach is designed to improve designers’ cognition and collaboration during the conceptual architectural design process. Findings – This paper evaluates the existing methods and decision support mechanisms, and it introduces the potential of combining different concepts into a single environment (generative design/BIM). Originality/value – This research is novel, in that it critically appraises virtual generative workspaces using BIM as the central conduit. The outcome and intervention of this research forms a theoretical basis for the development of a “proof of concept” prototype, which actively engages generative design into a single dynamic BIM environment to support the early conceptual design process.


2008 ◽  
Vol 44-46 ◽  
pp. 471-478
Author(s):  
Dong Xing Cao ◽  
Xiao Jun Zhang ◽  
Q.L. Jia ◽  
L.X. Nan

Configuration design lies in the later stage of the conceptual design. It affects the downstream of design process and decides product structure. Therefore, it is necessary to pursue an approach to support such design stage activities. Port, as the location of intended interaction, plays an important role in the configuration design, which abstractly represents the intended exchange of signals, energy or material in a convenient way. Ontology is an unambiguous and flexible semantic specification corresponding entities, and it can effectively describe the function of port. In this paper, we firstly give port concept and port functional description, and their semantic synthesis is used to describe port ontology. Second, we build an ontology repository which contains the assorted primitive concepts and primitive knowledge to map the component connections and interactions. Meanwhile we provide a model of port-based multi-views which contains functional view, behavior view and configuration view, and gives the attributes and taxonomy of ports. Next, a port-based ontology language (PBOL) is described to represent the process of port ontology refinement, and a port-based FBS modeling framework is presented to describe system configuration. Finally, a revised tape case is given to show the application of the port-based ontology.


Author(s):  
Ihab Ragai ◽  
Harry Tempelman ◽  
David Kirby

This paper deals with the utilization of topology optimization in the design process. Topology optimization is considered the most challenging task in the structural design optimization problems because the general layout of the structure is not known; however, implementing it in the conceptual design stage has proven to reduce the cost and development time. In this paper, the design process is briefly discussed emphasizing the use of topology optimization in the conceptual design stage. Also, the mathematical formulation for topology optimization with material density contours is presented. Furthermore, two industrial case studies, related to off-road mining and construction trucks, are discussed where the use of topology optimization has proven to dramatically improve an existing design and significantly decrease the development time of a new design.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sepehr Abrishami ◽  
Jack Goulding ◽  
Farzad Rahimian

PurposeThe integration and automation of the whole design and implementation process have become a pivotal factor in construction projects. Problems of process integration, particularly at the conceptual design stage, often manifest through a number of significant areas, from design representation, cognition and translation to process fragmentation and loss of design integrity. Whilst building information modelling (BIM) applications can be used to support design automation, particularly through the modelling, amendment and management stages, they do not explicitly provide whole design integration. This is a significant challenge. However, advances in generative design now offer significant potential for enhancing the design experience to mitigate this challenge.Design/methodology/approachThe approach outlined in this paper specifically addresses BIM deficiencies at the conceptual design stage, where the core drivers and indicators of BIM and generative design are identified and mapped into a generative BIM (G-BIM) framework and subsequently embedded into a G-BIM prototype. This actively engages generative design methods into a single dynamic BIM environment to support the early conceptual design process. The developed prototype followed the CIFE “horseshoe” methodology of aligning theoretical research with scientific methods to procure architecture, construction and engineering (AEC)-based solutions. This G-BIM prototype was also tested and validated through a focus group workshop engaging five AEC domain experts.FindingsThe G-BIM prototype presents a valuable set of rubrics to support the conceptual design stage using generative design. It benefits from the advanced features of BIM tools in relation to illustration and collaboration (coupled with BIM's parametric change management features).Research limitations/implicationsThis prototype has been evaluated through multiple projects and scenarios. However, additional test data is needed to further improve system veracity using conventional and non-standard real-life design settings (and contexts). This will be reported in later works.Originality/valueOriginality and value rest with addressing the shortcomings of previous research on automation during the design process. It also addresses novel computational issues relating to the implementation of generative design systems, where, for example, instead of engaging static and formal description of the domain concepts, G-BIM actively enhances the applicability of BIM during the early design stages to generate optimised (and more purposeful) design solutions.


Author(s):  
Kezheng Huang

As an essential part of design, the conceptual design needs computer assistance from its initial design stage of product development. However computer-aided conceptual design is limited by the current function-to-form mapping approaches. A new growth design process model is proposed in this paper in which geometrical solutions grow gradually from scratch to their complete configurations. Two theoretical design principles, Decomposition & Reconstitution (D&R) principle and Cell Division principle, are briefly introduced to provide better understanding of Growth Design model. The concept of Conceptual Structure is used to support the transition process from conceptual design to detailed design in the growth design process. Finally, an application case is introduced to show the effects of the growth design model.


Author(s):  
Dongxing Cao ◽  
Karthik Ramani ◽  
Ming Wang Fu ◽  
Runli Zhang

As the description of design requirements at the earlier design stage is inaccurate and vague, it is difficult to figure out functional structure of a product and make sense product configuration. Therefore, it plays an important role to formally represent the process of design for product development in the conceptual design stage. Furthermore, port, as the location of intended interaction, is crucial to capture component concept and realize conceptual design for multi-solution generation. Agent is considered as an effective approach to collaboratively implementing design problem solving and reasoning. Combining both port and agent may be employed to generate new concepts of the product in order to customize product scheme varieties. In this paper, the product module attributes are firstly described. The objective is to implement modeling of design process for obtaining system new concepts to guide multi-solution generation. Secondly, an effective approach to decomposing design process is presented to describe the process of structure generations and product decomposition by formal representation. According to properties of modularity for product development and component connections, we can calculate the number of component connections and density of components. In addition, product module division and coupling degree analysis are conducted, and coupling degrees are calculated by considering the correspondence ratio and the cluster independence. A port-based knowledge building process is described for functional modeling. A port-agent collaborative design framework is given and describes different agent functions to help designers to obtain new design schemes. Finally, a case study is presented to describe the modeling process of conceptual design.


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