Basic problems on the design of fiberglass reinforced plastic (FRP) ship hull structures are considered. The design procedures of FRP structures are considerably different from the conventional method of metal structures. FRP is a kind of composite materials and is inherently heterogeneous anisotropic, and the FRP structural design is closely connected with the FRP material design (in particular, the lamination design of FRP). Composite constructions such as stiffened panels and sandwich panels are important in FRP structural design, in order to compensate the low rigidity of FRP (one of the main faults of the material). In part I, the rigidity of FRP laminated plates (using chopped strand mats and woven rovings) are considered on the basis of classical theory of anisotropic laminates. Further, the large deflections of orthotropic membranes are considered by the energy method taking into consideration the initial small deflections, and compared with the hydrostatic pressure test results of FRP laminates. In part II, the rigidity and strength of FRP sandwich constructions with FRP faces and plastic foam core are discussed. Basic equations of rotation angles and deflection of sandwich plates with orthotropic membrane faces under lateral load are derived by the application of Cheng's theory (orthotropic core). The closed-form solutions are given in the case of simply supported edges and the finite difference solutions are given in the case of fixed edges. The latter are compared with the hydrostatic pressure test results of FRP sandwich panels. Typical examples of shear fracture modes of core after test are shown and discussed. Further, the bending behavior of FRP sandwich beams cut from the panels are discussed experimentally. In part III, seven kinds of simplified FRP composite structural models are fabricated and tested, in order to grasp the complex behavior of the actual FRP composite constructions. The bending behavior of these models are discussed from the view-point of the structural effectiveness. Simplified analyses are made on the effects of the shear deflection, the incomplete interaction of the stiffeners and the main beam, and the fall of effectiveness of the compression-side flange due to local deflections. Finally, the test results of these models are compared and discussed, defining the structural efficiency as the ratio of the so-called structural Young's modulus and that of the material.

  • Corporate Authors:

    Society of Naval Architects of Japan

    23 Shiba-kotohiracho, Minato-ku
    Tokyo 135,   Japan 
  • Authors:
    • Takehana, M
    • Kimpara, I
  • Publication Date: 1971

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Filing Info

  • Accession Number: 00035100
  • Record Type: Publication
  • Source Agency: Society of Naval Architects of Japan
  • Files: TRIS
  • Created Date: Oct 27 1973 12:00AM