Formal Representation of Product Design Specifications for Validating Product Design

Author(s):  
Alexander Weissman ◽  
Satyandra K. Gupta ◽  
Xenia Fiorentini ◽  
Rachuri Sudarsan ◽  
Ram Sriram

As collaborative efforts in electro-mechanical design have scaled to large, distributed groups working for years on a single product, an increasingly large gulf has developed between the original stated goals of the project and the final design solution. It has thus become necessary to validate the final design solution against a set of requirements to ensure that these goals have, in fact, been met. This process has become tedious for complex products with hundreds of design aspects and requirements. By formalizing the representation of requirements and the design solution, tools can be developed to a large extent automatically perform this validation. In this paper, we propose a formal approach for relating product requirements to the design solution. First, we present a formal model for representing product requirements. Then, we introduce the Core Product Model (CPM) and the Open Assembly Model (OAM) for representing the design solution. Finally, we link these models formally and provide an example with an actual consumer device.

2020 ◽  
Vol 15 ◽  
Author(s):  
Jin Li ◽  
Xingsheng Jiang ◽  
Jingye Li ◽  
Yadong Zhao ◽  
Xuexing Li

Background: In the whole design process of modular fuel tank, there are some unreasonable phenomena. As a result, there are some defects in the design of modular fuel tank, and the function does not meet the requirements in advance. This paper studies this problem. Objective: Through on-the-spot investigation of the factory, a mechanical design process model is designed. The model can provide reference for product design participants on product design time and design quality, and can effectively solve the problem of low product design quality caused by unreasonable product design time arrangement. Methods: After sorting out the data from the factory investigation, computer software is used to program, simulate the information input of mechanical design process, and the final reference value is got. Results: This mechanical design process model is used to guide the design and production of a new project, nearly 3 months ahead of the original project completion time. Conclusion: This mechanical design process model can effectively guide the product design process, which is of great significance to the whole mechanical design field.


2012 ◽  
Vol 622-623 ◽  
pp. 64-68 ◽  
Author(s):  
S. Padmanabhan ◽  
M. Chandrasekaran ◽  
P. Asokan ◽  
V. Srinivasa Raman

he major problem that deals with practical engineers is the mechanical design and creativeness. Mechanical design can be defined as the choice of materials and geometry, which satisfies, specified functional requirements of that design. A good design has to minimize the most significant adverse result and to maximize the most significant desirable result. An evolutionary algorithm offers efficient ways of creating and comparing a new design solution in order to complete an optimal design. In this paper a type of Genetic Algorithm, Real Coded Genetic Algorithm (RCGA) is used to optimize the design of helical gear pair and a combined objective function with maximizes the Power, Efficiency and minimizes the overall Weight, Centre distance. The performance of the proposed algorithms is validated through LINGO Software and the comparative results are analyzed.


Author(s):  
Stefan Wo¨lkl ◽  
Kristina Shea

The importance of the concept development phase in product development is contradictory to the level and amount of current computer-based support for it, especially with regards to mechanical design. Paper-based methods for conceptual design offer a far greater level of maturity and familiarity than current computational methods. Engineers usually work with software designed to address only a single stage of the concept design phase, such as requirements management tools. Integration with software covering other stages, e.g. functional modeling, is generally poor. Using the requirements for concept models outlined in the VDI 2221 guideline for systematic product development as a starting point, the authors propose an integrated product model constructed using the Systems Modeling Language (SysML) that moves beyond geometry to integrate all necessary aspects for conceptual design. These include requirements, functions and function structures, working principles and their structures as well as physical effects. In order to explore the applicability of SysML for mechanical design, a case study on the design of a passenger car’s luggage compartment cover is presented. The case study shows that many different SysML diagram types are suitable for formal modeling in mechanical concept design, though they were originally defined for software and control system development. It is then proposed that the creation and use of libraries defining generic as well as more complicated templates raises efficiency in modeling. The use of diagrams and their semantics for conceptual modeling make SysML a strong candidate for integrated product modeling of mechanical as well as mechatronic systems.


Author(s):  
Alexander Hacks ◽  
Sebastian Schuster ◽  
Hans Josef Dohmen ◽  
Friedrich-Karl Benra ◽  
Dieter Brillert

The paper aims to give an overview over the keystones of design of the turbomachine for a supercritical CO2 (sCO2) Brayton cycle. The described turbomachine is developed as part of a demonstration cycle on a laboratory scale with a low through flow. Therefore, the turbomachine is small and operates at high rotational speed. To give an overview on the development, the paper is divided into two parts regarding the aerodynamic and mechanical design. The aerodynamic design includes a detailed description on the steps from choosing an appropriate rotational speed to the design of the compressor impeller. For setting the rotational speed, the expected high windage losses are evaluated considering the reachable efficiencies of the compressor. The final impeller design includes a description of the blading development together with the final geometry parameters and calculated performance. The mechanical analysis shows the important considerations for building a turbomachine with integrated design of the three major components: turbine, alternator, and compressor (TAC). It includes different manufacturing techniques of the impellers, the bearing strategy, the sealing components, and the cooling of the generator utilizing the compressor leakage. Concluding the final design of the TAC is shown and future work on the machine is introduced.


Author(s):  
Ahmed Chowdhury ◽  
Lakshmi Narasimhon Athinarayana Venkatanarasimhan ◽  
Chiradeep Sen

Abstract Modern design problems often require multi-modal, reconfigurable solutions. Function modeling is a common tool used to explore solutions in early mechanical design. Currently, function modeling formalisms minimally support the modeling of multi-modal systems in a formal manner. There is a need in function modeling to capture multi-modal system and analyze the effects of control signals and status signals on their operating modes. This paper presents the concept of functional conjugacy, where two function verbs or functional subgraphs are topological opposites of each other. The paper presents a formal representation of these conjugate verbs that formally captures the transition from one mode of operation to its topological opposite based on the existence of, or the value of, signal flows. Additionally, this paper extends functional conjugacy to functional features, which supports conjugacy-based reasoning at a higher level of abstraction. Through the example of a system-level function model of a geothermal heat pump operating in its heating and cooling modes, this paper demonstrates the ability to support modal reasoning on function models using functional conjugacy and illustrates the modeling efficacy of the extended representation.


Author(s):  
Theodore Bardsz ◽  
Ibrahim Zeid

Abstract One of the most significant issues in applying case-based reasoning (CBR) to mechanical design is to integrate previously unrelated design plans towards the solution of a new design problem. The total design solution (the design plan structure) can be composed of both retrieved and dynamically generated design plans. The retrieved design plans must be mapped to fit the new design context, and the entire design plan structure must be evaluated. An architecture utilizing opportunistic problem solving in a blackboard environment is used to map and evaluate the design plan structure effectively and successfuly. The architecture has several assets when integrated into a CBR environment. First, the maximum amount of information related to the design is generated before any of the mapping problems are addressed. Second, mapping is preformed as just another action toward the evaluation of the design plan. Lastly, the architecture supports the inclusion of memory elements from the knowledge base in the design plan structure. The architecture is implemented using the GBB system. The architecture is part of a newly developed CBR System called DEJAVU. The paper describes DEJAVU and the architecture. An example is also included to illustrate the use of DEJAVU to solve engineering design problems.


Author(s):  
Ajantha Dahanayake

Historically the focus is on the theory of how problem-specific systems design tools can be supported by a Computer Aided Method Engineering (CAME) environment based on service object representation. To arrive at an implementation model, the conceptual model of the service object representation must be formalized. This theory is feasible when there is adequate computer support. Many researchers have emphasized strongly that requirement specification languages should have a rigorous formal basis; however, this need for formality has not been generally acknowledged in the field of information systems development. Most organizations and research groups tend to define their own methods using techniques advocated within such methods that often have no formal foundation. Discussions of modeling techniques are based on numerous examples, mostly using diagrams and notational conventions, to provide a popular style for the definition of new concepts and their behavior. In a CAME environment however, which gives the freedom to specify a modeling technique from scratch, it is difficult to avoid deficiencies such as inconsistency, lack of structure, over specification, incompleteness, ambiguity, and redundancy without using a formal approach. In automated support a formal model is used to provide stable specifications for implementation. In fact, an implementation can be seen as another, enormously detailed formal description, usually in an imperative programming language. To implement this sophisticated automated support, formal specifications of the CAME service description with adequate formal reasoning were derived earlier. In this chapter the concentration is on using representation formalism to construct a problem-specific CAME environment. Such an automated support environment must be provided for the information systems design stage in particular for the required UpperCASE tools according to the methods chosen for the problem situations. The vision is that CAME environments must function as a service-based, object-oriented MetaCASE environment that offers the services required for modeling tools, and using a mechanism to interpret the required modeling knowledge and changing the visual representation to the required form using a graphic object binding mechanism. Further, this environment must offer a mechanism for the populations of models specified according to such UpperCASE tools.


1991 ◽  
Vol 2 (2) ◽  
pp. 65-80 ◽  
Author(s):  
Charles M. Eastman ◽  
Alan H. Bond ◽  
Scott C. Chase

2015 ◽  
Vol 38 (1) ◽  
pp. 133-182 ◽  
Author(s):  
Patrice Enjalbert

This article is about the semantics of iterative statements, expressing repetition in time of a type-eventuality. With these statements are associated frequency properties, quantified by iterative adverbs (often, sometimes, sporadically, n times out of p…). Our purpose is to design a formal representation, with a method allowing to compute it from the text. The interpretation of an iterative statement closely relies on its information structure so that we first study precisely the topic-focus partition for a significant range of configurations. In the formal model, the occurrences of iterative eventualities or circumstants are represented by sequences of intervals. The temporal semantic of a sentence is then formalised as an instanciation of generic formulas using two types of generalised quantifiers.


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