Tham khảo tài liệu 'marine_structural_design episode 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Part I Structural Design Principles Chapter 6 Offshore Structural Analysis Introduction General This chapter describes the primary considerations that the design engineer should bear in mind during the initial design and subsequent structural analysis. In this chapter the notation Structures refers to all types of marine units ranging from floating ship-shaped vessels to bottom founded platforms. Emphasis has been placed on ship shaped structures. However consideration is also given to column supported structures . semi-submersibles tension leg platforms TLPs spars and mooring buoys and also to steel bottom founded offshore structures such as fixed steel jackets. The UK HSE completed a study on offshore structures in the North Sea which estimated that around 10-15 of failures were related to inadequate design either at the initial design phase or a subsequent upgrade in the design. Inadequacy in design includes lack of operational considerations failure to evaluate all structural elements and incorrect use of the design formulae. In the process of design the primary concerns for the designer are risks to life the structure the environment and project economy. Hence the relevant design codes and standards employ the appropriate safety factors in order to minimize these risks without being excessively conservative. Throughout this chapter emphasis is placed on the design process where the finite element analysis will be employed. Reference is made to the formulae used in the design of marine structures although these are not reproduced within this Chapter. These formulae may be found from Part n and Part in of this book together with the background information. Design Codes The designer is faced with a large number of rules codes standards and specifications describing the general policy for structure systems and the detailed design of structural components. These documents are produced and distributed by National Governments Certification .
