A Formal Representation of Function Structure Graphs for Physics-Based Reasoning

2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Chiradeep Sen ◽  
Joshua D. Summers ◽  
Gregory M. Mocko
Keyword(s):  
Computer Aided Design ◽  
Balance Laws ◽  
Formal Representation ◽  
Function Structure ◽  
Formal Reasoning ◽  
Ontology Language ◽  
Grammar Rules ◽  
Aided Design ◽  
Representational Validity ◽  
Local Grammar

The paper presents a formal representation for modeling function structure graphs in a consistent, grammatically controlled manner, and for performing conservation-based formal reasoning on those models. The representation consists of a hierarchical vocabulary of entities, relations, and attributes, and 33 local grammar rules that permit or prohibit modeling constructs thereby ensuring model consistency. Internal representational consistency is verified by committing the representation to a Protégé web ontology language (OWL) ontology and examining it with the Pellet consistency checker. External representational validity is established by implementing the representation in a Computer Aided Design (CAD) tool and using it to demonstrate that the grammar rules prohibit inconsistent constructs and that the models support physics-based reasoning based on the balance laws of transport phenomena. This representation, including the controlled grammar, can serve, in the future, as a basis for additional reasoning extensions.

Computer-Aided Design Synthesis Using Syntactic Solid Modeling

1994 ◽  
Author(s):  
Vassilios E. Theodoracatos ◽  
Xiaogang Guan
Keyword(s):  
Computer Aided Design ◽  
Solid Modeling ◽  
Large Set ◽  
Complex Structures ◽  
Design Synthesis ◽  
Computer Aided ◽  
Grammar Rules ◽  
Small Set ◽  
Definition Of ◽  
Aided Design

Abstract This paper presents a new Computer-Aided Design (CAD) synthesis model which uses Plex Grammar as structural relationship descriptors and NURBS surface representation for constructing standard and non-standard solid entities. Here, the designer uses a syntactic design methodology for early topological and geometrical definition of the structure of concept alternatives resulting from the design process. This syntactic scheme provides the capability of describing a large set of complex structures by using a small set of simple entities. The recursive nature of the grammar and the hierarchical representation of the structure makes the description of complex structures simple and under the direct control of the designer. An object structure constructive tree is generated and subsequently translated into Plex Grammar production rules in order to form an Interconnection Matrix (ICM) expressing. The resulting Plex structure defined in the ICM expresses the topological information among entities which form the specific types of objects. By modifying the Plex grammar rules, various objects with different geometry and topology can easily be reconstructed. Compared to conventional solid modeling techniques, this approach provides more systematic object generation, easy manipulation and modification, control over congruity and the ability to represent sculptured shapes. Several examples of syntactic solid modeling applied in design synthesis will be presented for further usage in downstream applications.

Status, Comparison, and Issues of Computer-Aided Design Model Data Exchange Methods Based on Standardized Neutral Files and Web Ontology Language File

2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Yuchu Qin ◽  
Wenlong Lu ◽  
Qunfen Qi ◽  
Xiaojun Liu ◽  
Yanru Zhong ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Data Exchange ◽  
Cad Model ◽  
Web Ontology Language ◽  
Model Data ◽  
Cad Systems ◽  
Ontology Language ◽  
Depth Analysis ◽  
Computer Aided ◽  
Aided Design

Exchanging computer-aided design (CAD) model data among heterogeneous CAD systems is indispensable for collaborative product development. Currently, the industry mainly uses the standardized neutral files-based methods to implement such exchange. While at the same time, the application of web ontology language (OWL) file and underlying semantic web technologies in CAD model data exchange is gaining importance and popularity within the academia. The coexistence of different types of methods has generated a series of controversies and questions within the industry and the academia. Yet, can the neutral files-based exchange methods completely implement model data exchange among heterogeneous CAD systems? What challenges have been addressed to date by the developed CAD model data exchange standards? Why OWL has been introduced to CAD model data exchange? Does CAD model data exchange really need OWL? Are there any issues in existing neutral files-based exchange methods and OWL file-based exchange methods need to be addressed in future studies? This paper proposes to conduct a study of the standardized neutral files-based exchange methods and OWL file-based exchange methods. An in-depth analysis of the widely used standard for the exchange of product model data (STEP) method and the newly emerging OWL methods is first provided. Then, the paper makes a detailed comparison between these two types of methods based on this analysis. Finally, some issues in the two types of methods that need to be addressed in the future are discussed.

Physics-Based Reasoning in Conceptual Design Using a Formal Representation of Function Structure Graphs

2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Chiradeep Sen ◽  
Joshua D. Summers ◽  
Gregory M. Mocko
Keyword(s):  
Real Time ◽  
Conceptual Design ◽  
Software Implementation ◽  
Balance Laws ◽  
Formal Representation ◽  
Function Structure ◽  
Logical Consistency ◽  
Universal Principles

This paper validates that a previously published formal representation of function structure graphs actually supports the reasoning that motivated its development in the first place. In doing so, it presents the algorithms to perform those reasoning, provides justification for the reasoning, and presents a software implementation called Concept Modeler (ConMod) to demonstrate the reasoning. Specifically, the representation is shown to support constructing function structure graphs in a grammar-controlled manner so that logical and physics-based inconsistencies are prevented in real-time, thus ensuring logically consistent models. Further, it is demonstrated that the representation can support postmodeling reasoning to check the modeled concepts against two universal principles of physics: the balance laws of mass and energy, and the principle of irreversibility. The representation in question is recently published and its internal ontological and logical consistency has been already demonstrated. However, its ability to support the intended reasoning was not validated so far, which is accomplished in this paper.

CAD Of Anticorrosive Protection Of Steel Structures

2019 ◽  
pp. 18-23
Keyword(s):  
Protective Coating ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Cost Effective ◽  
Operating Conditions ◽  
Computational Tool ◽  
Protection Method ◽  
Cost Effective Method ◽  
The Cost ◽  
Aided Design

The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.

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