A computational approach for fatigue crack propagation in ship structures under random sequence of clustered loading

• Okawa, T.

• Sumi, Yoichi

抄録

The authors have developed a simulation program, CP-System, for multiple cracks propagating in a three-dimensional stiffened panel structure, where through-the-thickness crack propagation is formulated as a two-dimensional in-plane problem, and the crack propagation behavior is simulated by step-by-step finite element analyses. In order to evaluate the fatigue lives of marine structures accurately, it is necessary to take into account the load histories induced by sea waves, which may be composed of a random sequence of certain clustered loads with variable stress range. In the proposed crack growth model, the crack opening and closure behavior is simulated by using the modified strip yielding model, and the effective tensile plastic stress intensity range, Delta K (RP), is calculated by considering the contact of plastic wake along the crack surfaces. The adequacy of the proposed crack growth model is examined by comparison with fatigue tests under non-constant-amplitude loading. The usefulness of the developed method is demonstrated for a ship structural detail under certain simulated load sequences. It is shown that the fatigue crack growth of a ship structure is significantly retarded due to the load interaction effects, so that the conventional method for fatigue life assessment may predict a relatively conservative fatigue life of a structure.

収録刊行物

• Journal of Marine Science and Technology

  Journal of Marine Science and Technology 13 (4), 416-427, 2008-11

  Springer Japan

キーワード

• Fatigue crack propagation
• Ship structures
• Clustered random loading
• Plastic stress intensity range

詳細情報

• CRID: 1050845762669241728
• NII論文ID: 10024487229
• NII書誌ID: AA11098465
• ISSN: 09484280
• Web Site: http://hdl.handle.net/10131/3867
• 本文言語コード: en
• 資料種別: journal article
• データソース種別:
  • IRDB
  • CiNii Articles
  • KAKEN