American Institute of Aeronautics and Astronautics 1 Some of the Topics in Composites Research Projects in Japan Takahira Aoki 1 and Tomohiro Yokozeki 2 University of Tokyo, Tokyo, Japan 113-8656 This paper presents an overview of the recent research activities on composite materials conducted in Japan. The main focus is on the projects related to carbon fiber reinforced plastics (CFRP) composites for the aerospace applications that are funded by the government or other public grants. The projects include those on: low cost composite materials manufacturing, advanced materials and process development for next generation aircraft structures, structural health monitoring of smart composite system, nanomaterial reinforced composites, advanced composite database system, and R&D of carbon fiber- reinforced composite materials to reduce automobile weight. I. Introduction here have been several projects, including relatively small ones, carried out in Japan that are related to the composite materials and their structures. Among these projects, some of them put intensive effort into high performance, advanced composites. In the following, the projects that are mainly led by the Japanese government or other public agencies, and focus on the advanced composite materials and their structures are briefly introduced. As the direct and potential application areas of these composites are aerospace field, most of them can be considered to be targeted on the structures of aerospace vehicles. Composites in air-breathing engines are not included, although propellant and fuel cell tank applications are not intended to be excluded. The organizations in parentheses following the project titles are the major funding bodies. II. Overview of the Research Projects A. Low Cost Composite Materials Manufacturing 1-3 (JAXA, Aviation Program Group) The project has pursued the development of manufacturing technology of the low cost composite material structure applicable to the primary structures of small passenger aircrafts. Although the existing composite applications are aiming at the overall manufacturing cost reduction as well as the weight reduction, no practical application to large monolithic or integral structures including main-wings have been realized. The cost reduction achieved by the current applications is mainly through the simplification of the maintenance procedures owing to the durable material characteristics of the CFRP. In these structures, prepregs are used in combination with the autoclaves that cause the cost increase. Integral structure can also reduce the manufacturing cost at an additional expense of inspections of the cured structures. Resin Transfer Molding (RTM) is the low cost manufacturing technology of the composites widely used to the industrial structures. This eliminates the need for large investment in facilities, and thus makes it possible for many smaller-scale manufacturers to fabricate the composite components. Vacuum assisted RTM (VaRTM) is the refined technology of the RTM with resin impregnation at lower temperature and pressure. One of the objectives of this project was to develop the technology to achieve increased manufacturing quality with less void content and no shortage of resin impregnation. The other objective was to clarify the subjects of type certification procurement of 1 Professor, Department of Aeronautics and Astronautics, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, Member, AIAA. 2 Associate Professor, Department of Aeronautics and Astronautics, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, Member, AIAA. T 50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference <br>17th 4 - 7 May 2009, Palm Springs, California AIAA 2009-2347 Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.