Sivand Lakmazaheri

Constraint logic programming for the analysis and partial synthesis of truss structures

This formulation is general in that it handles statically determinate and statically indeterminate trusses with pin and roller supports, and concentrated joint loads. The formulation is constraint-based in that the physical behavior of truss components is declaratively represented using constraints. The analysis and partial synthesis of a truss structure manifest themselves in proving the satisfiability of the constraints associated with the structural components. An artificial intelligence approach called constraint logic programming is used for representing and satisfying constraints. A constraint logic programming language, called CLP(R), is used for implementing the formulation

The analysis and partial synthesis of truss structures via theorem proving

A use of theorem proving for the analysis and partial synthesis of truss structures is presented. The behavior of a truss structure is modeled as the set union of the behavior of its constituent components where the behavior of each component is modeled by a set of constraints. This component/constraint model is formally represented by a set of axioms using predicate logic. The axioms are then used toanalyze and partiallysynthesize truss structures via theorem proving.Constraint logic programming is identified as a suitable implementation vehicle for the analysis and partial synthesis of truss structures via theorem proving. Several important implications of the formulation for structural design automation, data base integrity, and parallel processing are discussed.

A logic-based approach for processing design standards

A logic-based approach for automating the processing of design standards is illustrated. This approach is composed of three steps: conceptualization, formalization and implementation. Conceptualization is referred to as the representation of the knowledge necessary for solving the problem of interest in terms of objects and relations. Formalization is referred to as the representation of the objects and relations of interest as axioms using the language of predicate calculus. And, Implementation is referred to as the representation of the axioms of interest and the strategy for manipulating axioms using the constructs of a programming language. The paper illustrates the logic-based approach to engineering problem-solving automation by considering the portion of the AISC Specification that governs the design of axially loaded members. First, the relations of interest are identified (Conceptualization). Then, predicate calculus is used to formally represent the relations (Formalization) as axioms and to mechanically manipulate them. The checking and designing of structural components via mechanical manipulation of the axioms are illustrated in the paper. Finally, a constraint logic programming language is used to develop a computer program for automatic processing of the specification (Implementation). This program is composed of a set of rules that closely resemble the formulated axioms.

An artifact modeling approach for developing integrated engineering systems

Abstract Engineering problem solving can be viewed as a transformation process in which the initial description of an engineering system (artifact) transforms to its final description. This paper presents a single yet powerful approach for modeling engineering artifacts. The approach involves using (1) a symbolic language for representing engineering artifacts in terms of objects and relations and (2) a mechanical strategy for manipulating engineering artifacts. The approach provides a common platform for modeling different phases of the engineering problem solving process, thus facilitating system integration.

The development of a geometric modeling/database management interface

Abstract In order to transfer data between two software systems used as part of an overall CAD/CAM system for the design and manufacture of custom orthopedic footwear, we developed an interface program to map the systems imputs and outputs. This paper discusses the NASCAD-RIM Interface version 1.0 for these two systems, the NASCAD geometric modeler and the RIM relational database management system. This interface program for these widely used systems could prove useful to software developers and users.