DEVELOPMENT OF COMPUTER AIDED DESIGN AND MANUFACTURING SYSTEM FOR ADVANCED COMPOSITE MARINE STRUCTURES (2ND REPORT: DESIGN AND DEVELOPING CAD/CAE SYSTEMS FOR LAMINATED STRUCTURES)

The paper presents some basic concepts to develop a computer-aided design (CAD) systems for laminated materials for marine structures. A laminate is defined on surfaces with the use of surface-oriented coordinates, and compared with ordinary computer- aided engineering (CAE) defined laminates on finite elements. A mesh generator suitable for anisotropic materials and interfaces from CAD to CAE, and from CAD to computer-aided manufacturing are required in handling laminated composites. Some prototype CAD systems for laminated panel design are demonstrated, programmed by one of the object oriented languages, C++. It is shown that object oriented language is effective for defining laminate sequences, because of its function of class definition and its easiness to change classes. In the developed system, a layup sequence is defined on the surface with the use of a surface-oriented coordinate. Some prototypes of a CAE system for laminated panels are demonstrated, made up of preprocessor, analysis code and postprocessor. A general-purpose finite element analysis program MARC is used as the analysis code. The designed laminate panel is divided into finite elements concerned with material axis of anisotropic material, that is fibre direction. The analysis results are displayed on every layer of all regions and compared with ordinary post processor in which the results can be displayed on only one layer. It shows that the developed system is effective in designing and analysing laminated panels.