SUITABILITY OF HIGHER-STRENGTH STEELS FOR STRUCTURES SUBJECT TO FATIGUE STRESS

The Author reviews, in the light of current knowledge and published literature, the problem of whether it is advantageous to use a higher-strength steel, and if so of what type, in ship structures subject to fatigue stresses. The problem, which is complicated and has become more serious in recent years, is at present under investigation in ships in service and elsewhere. Methods (apart from reducing the fatigue loads) for improving the fatigue properties of ship structures include the development and careful fabrication of notch-free parts and connections; this is an essential measure, as only a limited improvement can result from the type of steel chosen. A higher-strength steel is often assumed to have higher fatigue strength, but such proportionality between static and dynamic strength is not applicable to hull structures. In such circumstances, the possibilities of using higher-strength steel to advantage in fatigue-stressed structures are few, but, from the point of view of the steel itself, the designer can follow certain principles. These principles, which are discussed in the article, include: unkilled steel should not be used; fatigue stresses through the material thickness should be avoided; reduced thickness of the higher-strength steel, and consequent change of stiffness and natural frequency of the components, will necessitate a resonance check; higher-strength steels should, in general, be avoided in the case of high-cycle alternating stresses, but can be advantageously used in certain other conditons; welded connections must receive special attention; and it should be noted that, in respect of corrosion fatigue, higher-strength steels have no advantage over ordinary steels. Order from: BSRA as No. 47,675.

  • Corporate Authors:

    VEB Autobahnbaukombinat

    Templinestrasse 19
    Potsdam,   Germany 
  • Authors:
    • Heider, F
  • Publication Date: 1977-9

Language

  • German

Media Info

  • Features: References;
  • Pagination: 3 p.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00173659
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Apr 26 1978 12:00AM