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Computer Aided Design in Composite Material Technology Proceedings of the International Conference, Southampton, 1988
Book review, Computer Aided Design in Composite Material Technology Proceedings of the International Conference, Southampton, 1988 Edited by: C. A. Brebbia, W. P. de Wilde and W. R. Blain
Computational Mechanics Publications, 1988 (£75.00) The title of this conference suggests that it was intended to cover computer aided design as applied to composite materials and structures. The papers which make up the proceedings do not live up to this expectation but are nevertheless a useful collection in their own right. Evans and Ferrar's paper on modelling the flow processing of short fibre composites describes simulation techniques which are used in the modelling process and, although a considerable amount of computing power is involved, this is potentially a very worthwhile development in the understanding of such processes. Moran et al. describe 'The processing of a composite finite element model with CADCOMP', a computer system for displaying finite element models for representing both composite and non-composite /naterial structures. The system provides a representation of stresses on a colour scale and stresses in the layers of a single element in bar chart form. ¢lartin's paper on computer automated optimal design ~flaminates describes a laminate analysis program, :~LACON, developed at the University of Ghent, chich has been combined with an automatic ,ptimization procedure. It appears to be a useful piece ,f software and has the advantage of being suitable for BM PC compatible computers as well as VAX omputers. 'astore and Ko's paper on CIM of braided preforms for omposites provides an introduction to the use of omputers in the design, analysis and manufacturing of ,raided preforms for advanced composites. ~ontributions by Kirberg and Menges on process mulation in filament winding and Abdelhady et al. on mputer aided design in filament winding of pressure vessels followed. ~ancox provides an interesting and worthwhile review 0f the thermal conductivity of composite materials. As he points o u t ' . . . all design methods require the input of realistic mechanical, thermal, electrical and chemical materials data' and' . . . rarely is all this information available and designers must fill in any gaps as best they can'. Despite the sophistication of software for use in composites design and a preoccupation in some quarters with the testing of composite materials, data suitable for use by designers in scarce. Non-mechanical design information is the rarest. This contribution therefore provides a valuable discussion of thermal
properties as well as being a useful source of data for preliminary design assessment. A contribution on heat conduction in composite plates by Minagawa follows and then two papers on computer simulation during the sintering process and the computer modelling of the processing of epoxy based composites are presented. Kandil and Verchery describe 'New methods of design for stacking sequences of composites'. The method outlined uses an apparently novel method of polar representation of the anisotropic properties of twodimensional systems. It is claimed that this method greatly facilitates the algebraic analysis and leads to a simple prediction of the characteristics of laminates. Zhang and Evans describe computer simulation of failure envelopes for composites. They give as an example the effect of varying the major Poisson's ratio on the failure envelopes of a material. Bergsma and Huisman describe a computer simulation exercise on the deep drawing of fabric reinforced thermoplastics. This method provides a useful indication of whether a product can be deep drawn or not, practical information for the deep drawing process. Where moulding is based on the computer simulations it is claimed that the products are of good quality, exhibiting sharp corners and an absence of wrinkles. Tiu et al. present details of a neat piece of investigative work into the prediction of the residual static strength of impacted composite laminates. Godwin and Davies' contribution is also on impact behaviour of composites but in this case thermoplastic composites. A comparison of the residual tensile and compressive strengths after increasing incident impact energies of thermoplastic composite with epoxy composite clearly shows that the former is more resistant to impact damage. High velocity impact damage prediction in composites is covered by Evans and Herne, though the work described is still in its early stages. In the section on numerical methods Van Gemert and Norree describe the finite element analysis of interlaminar stress singularities at free edges in laminates which involves the analysis of such singularities at the interface corner in cross-ply and angle-ply laminates. This offers the possibility of a reduction in the magnitude of interlaminar shear stresses by a proper choice of laminate thickness.
!
d;OMPOSITES . JANUARY 1989
91
investigation. It will be interesting to see how it develops in the future and whether or not it provides serious competition to finite element methods.
Zhang and Evans' second contribution is on the numerical prediction of the mechanical properties of composites with anisotropic components, using finite elements. This method is claimed to have the advantage of being able to determine the full set of 21 elastic constants for a fully anisotropic composite though tedious computations are involved.
Griffin and Vidussoni describe a method for the global/local finite element analysis of composite materials. This provides a useful technique for examining important areas of a composite structure without the use of very large computers, the analysis in the paper having been carried out on a DEC VAX machine.
Turvey presents the results of work on the shear buckling of anisotropic fibre-reinforced rectangular plates with central circular cut-outs. The behaviour of composite plates with cut-outs is one of the neglected areas of composites technology. This is therefore a welcome contribution to the understanding of such structural features.
While the title of the conference may, in some ways, seem to be a misnomer in the light of the papers presented the contents of the proceedings are nevertheless a worthwhile contribution to the composites field generally. Overall, this is an interesting and quite varied collection of papers. It is understood that a second conference is to be organized in Belgium in two years time. This therefore appears to be the start of another useful series of conferences in what is, admittedly, an already overcrowded calendar.
Zhen and Brebbia contribute a paper on the boundary element analysis of composite materials. Boundary element analysis seems to be gaining in popularity and it is claimed to compare favourably with other techniques used to solve anisotropic plate problems. There is little doubt that the application of this type of analysis to composite materials is worthy of serious
R. L. King
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/
Engineering Applications of Adhesives Papers from a one day seminar organised jointly by
The International Journal of Adhesion and Adhesives and RAPRA Technology Limited CONTENTS: Choice and change in fabrication • Adhesive selection • Solving cylindrical joint design problems with anaerobic adhesives • Liquid adhesive dispensing equipment • Robots for bonding • The use of structural adhesives in aerospace • Adhesives in the construction industry • Applications of electrically conductive adhesives in the electronics industry = Underwater applications of adhesives within the marine and offshore industries • Adhesives in the leisure industry • The use of adhesives in the automotive industry.
July 1988
88 pages
297 × 210ram
///ustrated
/SBN 0 408 26800 X
Softcover
£35.00
For further information complete and return the form below to Geraldine Hills, Butterworth Scientific Limited, PO Box 63, Westbury House, Bury Street, Guildford, Surrey GU2 5BH, UK .........................................................................................................................................
--~
.....................
..
Please send me further details on Engineering Applications of Adhesives Name
Address Postcode
\
92
Customers in Asia may order through: United Kingdom Butterworth & Co (Asia) Pie Ltd Butterworths, Borough Green Sevenoaks, Kent TN15 8PH 30 Robinson Road, Unit 12-01 Tuan Sing Towers England Singapore 0104, Republic of Singapore A-stralla & Papua New Guinea New Zealand Builerworths Pry Ltd, PO Box 345 Butterworths of New Zealand Lid North Ryde, New South Wales 2113 33-35Cumberland Place Australia Wellington 1, New Zealand
USA & Canada Butterworth Publishers 80 Montvale Avenue Stoneham, MA 02180, USA
]
COMPOSITES. JANUARY 198~
Computational Mechanics Publications, 1988 (£75.00) The title of this conference suggests that it was intended to cover computer aided design as applied to composite materials and structures. The papers which make up the proceedings do not live up to this expectation but are nevertheless a useful collection in their own right. Evans and Ferrar's paper on modelling the flow processing of short fibre composites describes simulation techniques which are used in the modelling process and, although a considerable amount of computing power is involved, this is potentially a very worthwhile development in the understanding of such processes. Moran et al. describe 'The processing of a composite finite element model with CADCOMP', a computer system for displaying finite element models for representing both composite and non-composite /naterial structures. The system provides a representation of stresses on a colour scale and stresses in the layers of a single element in bar chart form. ¢lartin's paper on computer automated optimal design ~flaminates describes a laminate analysis program, :~LACON, developed at the University of Ghent, chich has been combined with an automatic ,ptimization procedure. It appears to be a useful piece ,f software and has the advantage of being suitable for BM PC compatible computers as well as VAX omputers. 'astore and Ko's paper on CIM of braided preforms for omposites provides an introduction to the use of omputers in the design, analysis and manufacturing of ,raided preforms for advanced composites. ~ontributions by Kirberg and Menges on process mulation in filament winding and Abdelhady et al. on mputer aided design in filament winding of pressure vessels followed. ~ancox provides an interesting and worthwhile review 0f the thermal conductivity of composite materials. As he points o u t ' . . . all design methods require the input of realistic mechanical, thermal, electrical and chemical materials data' and' . . . rarely is all this information available and designers must fill in any gaps as best they can'. Despite the sophistication of software for use in composites design and a preoccupation in some quarters with the testing of composite materials, data suitable for use by designers in scarce. Non-mechanical design information is the rarest. This contribution therefore provides a valuable discussion of thermal
properties as well as being a useful source of data for preliminary design assessment. A contribution on heat conduction in composite plates by Minagawa follows and then two papers on computer simulation during the sintering process and the computer modelling of the processing of epoxy based composites are presented. Kandil and Verchery describe 'New methods of design for stacking sequences of composites'. The method outlined uses an apparently novel method of polar representation of the anisotropic properties of twodimensional systems. It is claimed that this method greatly facilitates the algebraic analysis and leads to a simple prediction of the characteristics of laminates. Zhang and Evans describe computer simulation of failure envelopes for composites. They give as an example the effect of varying the major Poisson's ratio on the failure envelopes of a material. Bergsma and Huisman describe a computer simulation exercise on the deep drawing of fabric reinforced thermoplastics. This method provides a useful indication of whether a product can be deep drawn or not, practical information for the deep drawing process. Where moulding is based on the computer simulations it is claimed that the products are of good quality, exhibiting sharp corners and an absence of wrinkles. Tiu et al. present details of a neat piece of investigative work into the prediction of the residual static strength of impacted composite laminates. Godwin and Davies' contribution is also on impact behaviour of composites but in this case thermoplastic composites. A comparison of the residual tensile and compressive strengths after increasing incident impact energies of thermoplastic composite with epoxy composite clearly shows that the former is more resistant to impact damage. High velocity impact damage prediction in composites is covered by Evans and Herne, though the work described is still in its early stages. In the section on numerical methods Van Gemert and Norree describe the finite element analysis of interlaminar stress singularities at free edges in laminates which involves the analysis of such singularities at the interface corner in cross-ply and angle-ply laminates. This offers the possibility of a reduction in the magnitude of interlaminar shear stresses by a proper choice of laminate thickness.
!
d;OMPOSITES . JANUARY 1989
91
investigation. It will be interesting to see how it develops in the future and whether or not it provides serious competition to finite element methods.
Zhang and Evans' second contribution is on the numerical prediction of the mechanical properties of composites with anisotropic components, using finite elements. This method is claimed to have the advantage of being able to determine the full set of 21 elastic constants for a fully anisotropic composite though tedious computations are involved.
Griffin and Vidussoni describe a method for the global/local finite element analysis of composite materials. This provides a useful technique for examining important areas of a composite structure without the use of very large computers, the analysis in the paper having been carried out on a DEC VAX machine.
Turvey presents the results of work on the shear buckling of anisotropic fibre-reinforced rectangular plates with central circular cut-outs. The behaviour of composite plates with cut-outs is one of the neglected areas of composites technology. This is therefore a welcome contribution to the understanding of such structural features.
While the title of the conference may, in some ways, seem to be a misnomer in the light of the papers presented the contents of the proceedings are nevertheless a worthwhile contribution to the composites field generally. Overall, this is an interesting and quite varied collection of papers. It is understood that a second conference is to be organized in Belgium in two years time. This therefore appears to be the start of another useful series of conferences in what is, admittedly, an already overcrowded calendar.
Zhen and Brebbia contribute a paper on the boundary element analysis of composite materials. Boundary element analysis seems to be gaining in popularity and it is claimed to compare favourably with other techniques used to solve anisotropic plate problems. There is little doubt that the application of this type of analysis to composite materials is worthy of serious
R. L. King
\
/
Engineering Applications of Adhesives Papers from a one day seminar organised jointly by
The International Journal of Adhesion and Adhesives and RAPRA Technology Limited CONTENTS: Choice and change in fabrication • Adhesive selection • Solving cylindrical joint design problems with anaerobic adhesives • Liquid adhesive dispensing equipment • Robots for bonding • The use of structural adhesives in aerospace • Adhesives in the construction industry • Applications of electrically conductive adhesives in the electronics industry = Underwater applications of adhesives within the marine and offshore industries • Adhesives in the leisure industry • The use of adhesives in the automotive industry.
July 1988
88 pages
297 × 210ram
///ustrated
/SBN 0 408 26800 X
Softcover
£35.00
For further information complete and return the form below to Geraldine Hills, Butterworth Scientific Limited, PO Box 63, Westbury House, Bury Street, Guildford, Surrey GU2 5BH, UK .........................................................................................................................................
--~
.....................
..
Please send me further details on Engineering Applications of Adhesives Name
Address Postcode
\
92
Customers in Asia may order through: United Kingdom Butterworth & Co (Asia) Pie Ltd Butterworths, Borough Green Sevenoaks, Kent TN15 8PH 30 Robinson Road, Unit 12-01 Tuan Sing Towers England Singapore 0104, Republic of Singapore A-stralla & Papua New Guinea New Zealand Builerworths Pry Ltd, PO Box 345 Butterworths of New Zealand Lid North Ryde, New South Wales 2113 33-35Cumberland Place Australia Wellington 1, New Zealand
USA & Canada Butterworth Publishers 80 Montvale Avenue Stoneham, MA 02180, USA
]
COMPOSITES. JANUARY 198~