Engineering software

gg

(_omputers m lndu~trl

cedures but also enable the direct access to higher level data bank systems w~th its informauon of general interest These are the conditions under whmh the computer integrated manufacturmg (CIM) and computer aided design (CAD) can be used m order to cope w~th competition and economm situations changing rapidly Within the wide field of mdustrlal manufacturing the trend to install more "'Intelligent" robots, working stations and production control systems can be observed The capabdiUes of machmes are extended m such a way that they can recognize patterns w~thin the characteristic behavior of their operators These patterns can be analyzed in order to avoid future failures and to optimize the m a n - m a c h i n e interaction During the conference a report was given about new handhng systems - for example a new' Japanese robot with three-dimensional sensors and stereoscopic vision The results of the 8th Conference on Production Research have put the emphasis on three essentials 1 The Factory of the Future is not destgnated as an isolated model, but requires interdisciplinary cooperation between all relevant research actlv]tle~

( ,otter, ~t, : R~ t','p:,

2 The attitude of the entrepreneurs toward the new findings of production research ~lll not onlTy be decisive with respect to meet competition, but also with respect to the de~eloplnent of places of employment The risk of a rise m unemployment is more severe from neglectmg technical innovations than lrom demographic developments 3 The challenge by the new technical posslblllUes requires a drastlcal change m our attitudes with respect to qualification These new quahficatlon reqmrements hold for all levels of management as well as for the operators within the production hne The papers of the 8th Conference on Prodm,tlon Research are published in H - J Bulhnger and H J Warnecke. T o w a r d t h e F a e t o o ' oj' t h e F u t u r e Proceedings of the 8th ICPR, Stuttgart, August 1985 Springer, Berlin-Heidelberg-New York-Tokyo ISBN 0 387-15762X The findings of the National Science Foundation Conference on Manufacturing Research Orgamzauonal and International Issues, ed by' A Gerstenfeld, H - J Bulllnger and H J Warnecke, will be published by Elsevier Science Publishers in Sprmg, 1986

Engineering Software The 4th International Conference 'Engsoft 85' on Engineering Software was held at Kensington Exhibition Centre, London, UK on June 18-20, 1985 Accordmg to R A A d e y (Computational Mechanics Centre, Southampton, Hampsh0re, UK) who edited the conference proceedings, "( ) Advances m computer hardware have provided low-cost powerful microcomputers, high-performance graphical d~splays and super computers which enable problems to be solved in engmeermg ( ) Similar changes have taken place m the development of engmeermg software Sophisticated graphics-based modellmg systems and advanced mathematical modelhng have provided solut0ons to previously unsolvable problems and, together with microcomputers and powerful mmt-computers, have made such solutions widely available"

The conference sessions mcluded Software Development, Construction, Numerical Methods, Engmeermg Apphcatton of Expert Systems, Micro Apphcattons, Structural Engmeermg, Hydraulics, Geometric Modelling, Simulation and Databases m Engmeenng The emphasis of the conference was on new applications, which was reflected in the many papers on expert systems, engmeenng databases and micro applications However, the more so-called mature apphcatton areas were also well represented We present below a selection from the numerous lectures dehvered at the conference

Conference Report~

Software Development Thoughts on Design, Development and Mamtenance In this lecture K Bell (Norwegian Institute of Technology, Trondheim, Norway) gave his view on the problems surrounding the poor quality of software in general and engineering software in particular Bell is a structural engineer, with little training in computer programn~ng, but he has been involved in the design, development and maintenance of engineering software for about twenty years Finite element techniques, FORT R A N and small- to medium-sized special purpose programs are key items in Ins work Together with others he produced a " H a n d b o o k of Computer Programming" (Trondhelm, 1983) covering sections on the Digital Computer, F O R T R A N Syntax and Semantics, Program Specification and Design, Data Management, Programming Style, Errors, Testing and Bugging, Documentation, Maintenance, Implementation and Distnbution, Standard Software and Miscellaneous In this lecture Bell gave a brief review of each section and emphasized the main points in the light of their experiences and current opinions The Handbook poses the crucial question of who should design, develop and maintain engineering software According to Bell each section stresses ItS specific purpose, while examples and practical solutions are provided Guidelines are presented and techniques recommended The overall emphasis is on a standard and uniform approach within an organization The Handbook addresses Itself to the programmer of engineering software with little formal training in computer programming, and alms to bridge the gap between the professional programming and the engineering or F O R T R A N community Bell holds the point of view that Improved programmer skills and effective project management are essential elements in both the development and maintenance of any software product

Computerv tn Industry

89

tlon derived from this type of system depends on many variables The study described in this lecture by A. and S Rushmek (University of Miami, Coral Gables, FL, USA) analyzed the influence of a number of ESS predictor variables on overall satisfaction The Rushmek's reported that the study confirmed the theories which suggest that ESS ease of operation, computer rellabxhty, technical support and trouble shooting are the major determinants of overall computer user satisfaction Multiple regression had been used to study the dependence of this satisfaction on an ESS system with many ESS variables The implications are not only important to system users but also to buyers and vendors Selection of Process Equipment Process equipment is specified at the design stage by well established technical considerations However, selection of items of equipment is dependent on the skill and experience of specialist procurement engineers and access to large uncoordinated databases such as manufacturer's technical literature In this talk P Norman and Y W Voon (University of Newcastle-upon-Tyne, UK) examined the development of expert systems in the selection of process equipment by highlighting the development of expert systems for valve selection, since valves are quite varied but also relatively simple pieces of equipment The consultation programs were examined under three different environments, namely PASCAL, LISP and PROL O G They dealt with the advantages and disadvantages and discussed efficient ways of making decisions for process valve selection They concluded that all three environments are stated to the task and suggested appropriate decision-making techniques within each enwronment

Numerical Methods Elgenvalue Problems

Engineering Applications of Expert Systems Expert System Using Telecommumcattons Selecting an Engineering and Scientific (ES) software system is a lengthy process The satisfac-

An efficient implementation of the Subspace Iteration Method to calculate the elgenvalues and elgenvectors of structures with a large number of degrees of freedom was described by A vale e Azevedo (National Laboratory of Civil Engineering, Lisbon, Portugal) In tins method the unity

90

Computer~ in Industr~

( o n h t t ' m ~ Rep.tl~

t~me spent by the computer's central processor was opumlzed, a balance m the use of central memory poSltlOn and transferences to auxflmr~ memory was adopted, and the problems of numerical precxsaon and stabdaty w~th regard to the matrix factorlzatlon were taken into account The Sturm sequence property to verify ff the reqmred elgenvalues and elgenvectors have been calculated was also amplemented Some numerical examples were gwen which demonstrated the most efflc~ent computatmnal implementations

the estimating process whale having the advantages of less probabfllt'v of error and greater unlformlt,~ in price Ward reported that the package deals wath the creanon of standard databases (welding and drllhng tames etc ) and with the producmm of the actual estimate which basacally follows the same hne of thought as m manual est|matmg Ward reported that the program has come up to expectations in terms of tame saved and the accuracy and umformlty of results

Collocatwn Fmtte Element Method

Geometric Modelling

N G Zamam and S N Sarwal (Umverslty of N o v a Scotia, Hahfax, NS, Canada) proposed a fimte element-based collocation procedure which was used to calculate the elgenvalues of several differential operators in one and two &mens~ons They dealt with three problems of significance to engineering m order to assess the performance and accuracy of the method These were second and fourth order boundary value problems in one dimension and the Helmholtz equatmn in two &menslons Problems arise m the vlbratlon of strings, beams and membranes According to Zamanl and Sarwal the major advantage of collocation over the standard finite elements ~s that no quadrature formulas are required Collocatmn codes are therefore very efficient A disadvantage ~s related to the fact that ~t can only be applied to dffferentml equations described in an orthogonal coordinate system

Quadratic Sphnes Owing to theoretical and computational conslderatmns, most practical CAD systems use parametric curves and surfaces in geometric modellang In their lecture, F Fenyves and G Kovhcs (Hungarian Academy of Sciences, Budapest, Hungary) dealt with quadratic sphnes and thear application for curve and surface representatmn A problem they were confronted with was to present a method for obtaining a smooth bwarlate functmn which takes place on certain prescribed values The collection of these values ts assumed to be on a rectangular grid, that is, for every point on the grid there is a given value They gave a short account of some results and presented th~s using a selected form of the general quadratic sphnes, the G-sphnes In addition a new technique for representing continuous, respectively smooth, surfaces was presented

Structural Engineering Simulation Esttmatmg Package Random Signals Analyses According to H C Ward (Teeslde Polytechmc, Mlddlesborough, U K ) the present methods of preparing estimates for fabricated structures vary slightly in detail, but generally revolve a lengthy process m which vastly different outcomes may result The use of computers for estimation purposes Is therefore essential, with the criteria to be met being speed, accuracy, umforrmty and the ability to be used on microcomputers as well as larger mainframe or super-rmm computers Ward described a modular computer package, COMEST, whtch was developed to assist xn speeding up

The interrelations between vehicle and track can be described m terms of transfer functions, indicating how the various geometry components contribute to a g~ven response component of the vehicle C Eshuts (Netherlands Railways, The Netherlands) described a method which proceeds from measured geometry s~gnals (input) and a corresponding vehicle signal (output). between which transfer functions are estabhshed with the aid of the Multiple Input, Single Output (MISO) method Th~s method is based on the theory of

Conference Reports

random signal analysis The Netherlands Railways will use the method to obtain transfer functmns from a representative cross-sectional view of the rolling stock park, at various hne speeds These will be implemented to enable the on-line computation of the vehicle response during measuring runs, for assessing track quality There are also a number of apphcatlons in the field of rolhng stock

Computers m Industry

91

assessment, in which MISO could be a practical resource for verifying the transfer characteristics of new rolling stock categories The Proceedings of the Conference are a Computational Mechanics Pubhcatlon of Spnnger Verlag, Berlin, Heidelberg, New York, Tokyo ISBN 3-540-15493-0