- Email: [email protected]
Drafting — the unique module approach
plotter• A record-playback facility permits small assemblies to be stored as packages on magnetic cards; large drawings may be stored on a floppy disc. A balance sheet of advantages and disadvantages is included. Mr R K Hilton had worked in the automobile, steam-turbine, glass making, cablemaking and lamp-making industries before joining the Atomic Energy Authority. His interest in CAD is incidental to his main work as a project engineer.
Drafting - the unique module approach C Mattingly (Chief Research Engineer, IDC
allowing one to correct the data at the preprocessing stage before the finite element computation itself is started. Professor Kenneth Preiss has been with the Department of Mechanical Engineering at the Ben Gurion University of the Negev since its inception in 1967. He is currently Head of the CADCAM Centre at the university.
LUCID - a cooperative venture in CAD L L Jones, R H Mayo and P Charlton
Consultants Ltd, Stratford on A van, UK)
(Loughborough University, UK) A J M Soane (Bingham, Bladesand Partners, UK)
CAD is generally thought of as a system for producing a wide range of drawings. Facilities for drawing lines and characters are provided, together with the ability to create sub-images which are assembled into the final product. This paper suggests a totally different approach based on the concept of a unique class of drawings, for example all site survey drawings or all floor layouts. The features common to the class are assembled to complete the product by a package which locates them according to the logic of the unique drawing described. The package is here described as a Unique Drawing Module (UDM). It is argued that this involves less programming effort per installation, less training and simpler equipment.
After a brief historical review of LUCID, a cooperative organization between Laughborough University of Technology and over 100 firms in the construction industry, a simple manual technique for producing notto-scale reinforced concrete drawings which has been developed is described. It is then indicated that a successful pilot study on reinforced concrete beam drawings using the graphics package CABLOS and a new program SCALAR will enable the extensive library of not-to-scale drawings for beams, columns, slabs, walls, stakcases, foundations, culverts and retaining walls to be used to produce their scale equivalents. The paper is concluded with proposals for the development and funding of an even more extensive drawing system.
Chris Mattingly studied Electronics and Civil Engi~neering, and has since held a wide variety of posts in design and construction, currently Chief Research and Development Engineer with IDC Consultants, and has been responsible among other things for CAD applications.
Graphic interaction in a drafting system based on two-dimensional primitives G Cosmai, U Cugini, and N Napolitano
(Po/itecnico di Milano, Italy) J P Mussio (LFCTR de/CNR, Milan, Italy) This work illustrates an interactive graphic system for technical drawing based on 2D primitives, with special attention to the ways of interaction derived from the study of the usual drawing procedures.
STRUCTURES
Topological consistency rules for general finite element meshes K Preiss (Ben Gurion University of the Negev, Israel) The paper describes algorithms, based on principles of geometric modelling and graph theory, for checking the topological consistency of a 2D or 3D finite element mesh. The mesh may consist of any mixture of any shape elements. The algorithm detects any topological inconsistency in the mesh,
v o l u m e 14 n u m b e r :2 march 1982
C o m p u t e r - a i d e d design o f c o n v e y o r structures M C Thakkar and S J Shah (Elecon
Engineering Co Ltd, India) Conveyor structures such as gantries and trestles have many parameters which depend on functional requirements. The authors, taking into account various design parameters, code constraints, material availability and functional requirements aim for the optimal design output with minimum input. The structure analysis does not need to be repeated in the CAD system developed by the authors. Actual applications of the system are presented, which have already shown considerable savings in various projects already commissioned. The system can be used as pre-processor to get the detailed fabrication drawings through a computer graphic system. M C Thakkar, BE, MTech, PhD, FIE (India), Chief Structural Design Engineer, ELECON has major interests in computer-aided design and drafting techniques along with optimization in structural design. S J Shah BE, ME, MIE (India), Technical Executive in Structural Design Department in ELECON has major interests in the design of various structural frameworks in heavy machines needed in material handling systems. The B E A S Y system D Danson, C A Brebbia~ and R A Adey
(Computational Mechanics Centre, UK) The FEM may be seen as a method of solving boundary value problems where the
phenomenon in the domain being studied obeys known differential equations. The domain is formed into a number of elements in each of which the solution of the governing equation is approximated by some function which satisfies the boundary conditions. An alternative approach is to use functions which satisfy the differential equation in the domain but not the boundary conditions. The boundary may be divided into elements and the boundary values assumed to vary in some manner within these elements. A set of equations may then be formulated in terms of nodal values, with the nodes only on the boundaries.
M I C R O S IN T H E D E S I G N OFFICE
The economics o f m i c r o c o m p u t e r use in the engineering design office c J Clifton (EngineerinqSciencesData Unit,
UK) Today every professional engineering designer entering industry is capable of both writing programs and using computers. However, the use of desktop machines is not widespread in the design office environment and pressure is being brought to bear for their introduction. This paper examines the pitfalls associated with the adoption of microcomputers especially in relation to hardware limitations and software requirements.
The design of radio transmitter combiners using a microcomputer P R and D P Howson (Bradford University, UK) Radio transmitter combiners using numbers of cavity resonators interconnected by coaxial cables can be designed on an interactive basis using a microcomputer such as the PET. This inexpensive interactive facility allows professional engineers access to design information both in the laboratory, and on location during work on combiner modifications. The form of the BASIC program is discussed, and also the relative virtues of using either experimental or model data for the resonators. An appropriate resonator model for this use has been developed. D P Howson took his BSc at Bristol University in 1952. He then spent five years in industry as a design engineer with Standard Telephone and Cables before taking his MSc in Information Engineering at Birmingham University. From 1958 to 1967, he was successively appointed Lecturer and Senior Lecturer at Birmingham University. He was appointed to his present position as • Professor of Electrical Engineering at the University of Bradford in 1968. He obtained his DSc from the University of Birmingham in 1968. His research work has been in the field of communications systems and circuits; more latterly in the fields of radio frequency hazards and mobile radio systems. P R Howson took his BSc at Birmingham University in 1977. He then spent two years in industry before taking his MSc in Electro-
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Drafting - the unique module approach C Mattingly (Chief Research Engineer, IDC
allowing one to correct the data at the preprocessing stage before the finite element computation itself is started. Professor Kenneth Preiss has been with the Department of Mechanical Engineering at the Ben Gurion University of the Negev since its inception in 1967. He is currently Head of the CADCAM Centre at the university.
LUCID - a cooperative venture in CAD L L Jones, R H Mayo and P Charlton
Consultants Ltd, Stratford on A van, UK)
(Loughborough University, UK) A J M Soane (Bingham, Bladesand Partners, UK)
CAD is generally thought of as a system for producing a wide range of drawings. Facilities for drawing lines and characters are provided, together with the ability to create sub-images which are assembled into the final product. This paper suggests a totally different approach based on the concept of a unique class of drawings, for example all site survey drawings or all floor layouts. The features common to the class are assembled to complete the product by a package which locates them according to the logic of the unique drawing described. The package is here described as a Unique Drawing Module (UDM). It is argued that this involves less programming effort per installation, less training and simpler equipment.
After a brief historical review of LUCID, a cooperative organization between Laughborough University of Technology and over 100 firms in the construction industry, a simple manual technique for producing notto-scale reinforced concrete drawings which has been developed is described. It is then indicated that a successful pilot study on reinforced concrete beam drawings using the graphics package CABLOS and a new program SCALAR will enable the extensive library of not-to-scale drawings for beams, columns, slabs, walls, stakcases, foundations, culverts and retaining walls to be used to produce their scale equivalents. The paper is concluded with proposals for the development and funding of an even more extensive drawing system.
Chris Mattingly studied Electronics and Civil Engi~neering, and has since held a wide variety of posts in design and construction, currently Chief Research and Development Engineer with IDC Consultants, and has been responsible among other things for CAD applications.
Graphic interaction in a drafting system based on two-dimensional primitives G Cosmai, U Cugini, and N Napolitano
(Po/itecnico di Milano, Italy) J P Mussio (LFCTR de/CNR, Milan, Italy) This work illustrates an interactive graphic system for technical drawing based on 2D primitives, with special attention to the ways of interaction derived from the study of the usual drawing procedures.
STRUCTURES
Topological consistency rules for general finite element meshes K Preiss (Ben Gurion University of the Negev, Israel) The paper describes algorithms, based on principles of geometric modelling and graph theory, for checking the topological consistency of a 2D or 3D finite element mesh. The mesh may consist of any mixture of any shape elements. The algorithm detects any topological inconsistency in the mesh,
v o l u m e 14 n u m b e r :2 march 1982
C o m p u t e r - a i d e d design o f c o n v e y o r structures M C Thakkar and S J Shah (Elecon
Engineering Co Ltd, India) Conveyor structures such as gantries and trestles have many parameters which depend on functional requirements. The authors, taking into account various design parameters, code constraints, material availability and functional requirements aim for the optimal design output with minimum input. The structure analysis does not need to be repeated in the CAD system developed by the authors. Actual applications of the system are presented, which have already shown considerable savings in various projects already commissioned. The system can be used as pre-processor to get the detailed fabrication drawings through a computer graphic system. M C Thakkar, BE, MTech, PhD, FIE (India), Chief Structural Design Engineer, ELECON has major interests in computer-aided design and drafting techniques along with optimization in structural design. S J Shah BE, ME, MIE (India), Technical Executive in Structural Design Department in ELECON has major interests in the design of various structural frameworks in heavy machines needed in material handling systems. The B E A S Y system D Danson, C A Brebbia~ and R A Adey
(Computational Mechanics Centre, UK) The FEM may be seen as a method of solving boundary value problems where the
phenomenon in the domain being studied obeys known differential equations. The domain is formed into a number of elements in each of which the solution of the governing equation is approximated by some function which satisfies the boundary conditions. An alternative approach is to use functions which satisfy the differential equation in the domain but not the boundary conditions. The boundary may be divided into elements and the boundary values assumed to vary in some manner within these elements. A set of equations may then be formulated in terms of nodal values, with the nodes only on the boundaries.
M I C R O S IN T H E D E S I G N OFFICE
The economics o f m i c r o c o m p u t e r use in the engineering design office c J Clifton (EngineerinqSciencesData Unit,
UK) Today every professional engineering designer entering industry is capable of both writing programs and using computers. However, the use of desktop machines is not widespread in the design office environment and pressure is being brought to bear for their introduction. This paper examines the pitfalls associated with the adoption of microcomputers especially in relation to hardware limitations and software requirements.
The design of radio transmitter combiners using a microcomputer P R and D P Howson (Bradford University, UK) Radio transmitter combiners using numbers of cavity resonators interconnected by coaxial cables can be designed on an interactive basis using a microcomputer such as the PET. This inexpensive interactive facility allows professional engineers access to design information both in the laboratory, and on location during work on combiner modifications. The form of the BASIC program is discussed, and also the relative virtues of using either experimental or model data for the resonators. An appropriate resonator model for this use has been developed. D P Howson took his BSc at Bristol University in 1952. He then spent five years in industry as a design engineer with Standard Telephone and Cables before taking his MSc in Information Engineering at Birmingham University. From 1958 to 1967, he was successively appointed Lecturer and Senior Lecturer at Birmingham University. He was appointed to his present position as • Professor of Electrical Engineering at the University of Bradford in 1968. He obtained his DSc from the University of Birmingham in 1968. His research work has been in the field of communications systems and circuits; more latterly in the fields of radio frequency hazards and mobile radio systems. P R Howson took his BSc at Birmingham University in 1977. He then spent two years in industry before taking his MSc in Electro-
111