Constructive solid geometry approach to three-dimensional structuralshape optimization

AIAA Journal ◽  
1992 ◽  
Vol 30 (5) ◽  
pp. 1408-1415 ◽  
Author(s):  
Srinivas Kodiyalam ◽  
Virendra Kumar ◽  
Peter M. Finnigan
Keyword(s):  
Three Dimensional ◽  
Constructive Solid Geometry ◽  
Solid Geometry

Equipment workspace analysis in infrastructure projects

2007 ◽  
Vol 34 (10) ◽  
pp. 1247-1256 ◽  
Author(s):  
Amin Hammad ◽  
Cheng Zhang ◽  
Mohamed Al-Hussein ◽  
Germain Cardinal
Keyword(s):  
Three Dimensional ◽  
Construction Equipment ◽  
Prototype System ◽  
Constructive Solid Geometry ◽  
Infrastructure Projects ◽  
Bridge Construction ◽  
Solid Geometry ◽  
Workspace Analysis ◽  
Computational Aspects

Workspace conflicts are one of the important problems that can delay construction activities, reduce productivity, or cause accidents that threaten the safety of workers. Workspace planning is particularly important in the case of large infrastructure projects, such as bridge construction, and rehabilitation projects where equipment with complex workspace requirement is required. This paper aims to extend the previous research on workspace representation and analysis in the case of large infrastructure projects focusing on the following issues: (i) specific representation of equipment workspaces using composite shapes, (ii) semiautomatic generation and analysis of workspaces, and (iii) development of a prototype system that can generate workspaces and detect spatiotemporal conflicts in a three-dimensional environment. The computational aspects of the proposed approach are discussed and demonstrated through the development of a prototype system, which has been applied in a case study of the deck replacement of Jacques Cartier Bridge in Montréal.Key words: workspace analysis, spatiotemporal conflicts, construction equipment, infrastructure projects, bridge redecking, constructive solid geometry.

A Fast Wireframe Display Algorithm for Hidden Surface Removal in Constructive Solid Geometry

1991 ◽  
Author(s):  
Shyr-Long Jeng ◽  
Wei-Hua Chieng ◽  
David A. Hoeltzel
Keyword(s):  
Three Dimensional ◽  
Surface Topology ◽  
Constructive Solid Geometry ◽  
Boundary Edge ◽  
Finite Point ◽  
Graphical Simulation ◽  
Solid Geometry ◽  
Set Membership ◽  
Nc Machine ◽  
Representation Scheme

Abstract A fast algorithm for rendering three dimensional geometry as wireframes is developed. The algorithm employs a constructive solid geometry (CSG) model as its underlying geometric representation scheme, set membership classification for the removal of non-boundary lines, and a finite-point backward ray tracing method for hidden line removal. By eliminating conventional polygon surface approximation and its associated surface topology representation, requiring high information overhead, the algorithm demonstrates speed and simplicity. The primary purpose of the algorithm is for expeditious real-time graphical simulation, particularly for interactive design. The algorithm demonstrates overall time complexity of O(n2 h*2), where n denotes the total number of geometric primitives, and h* denotes the total number of boundary edge segments. Desirable side effects associated with the use of set membership classification include the ability to generate NC machine instructions and the detection of object interference for collision avoidance during the simulation of manufacturing processes. Examples demonstrating the visualization of 3-D mechanical components are included.

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