DNV DNVGL-RU-SHIPS PART 3 CHAPTER 7 PDF

General

Introduction

This chapter describes modelling techniques, loads, acceptance criteria and required documentation for finite element(FE) analysis. See Ch.4 Sec.8 for definition of loading conditions and Pt.5 for ship type application when required.

Calculation methods

The rules cover four levels of finite element analysis (FEA):

a) Global direct strength analysis, to assess hull girder strength and to give correct boundary conditions to partial ship structural models and/or local FE models, when applicable.

b) Partial ship structural analysis, to assess the strength of longitudinal hull girder structural members, primary supporting structural members and bulkheads.

c) Local structure analysis, to assess local stress levels for ultimate limit state (ULS).

d) Very fine mesh analysis, to assess the local structural details for fatigue limit state (FLS), as described in Ch.9.

a) to c) are described in Sec.2 to Sec.4.

The objectives of the analyses together with their applicable acceptance criteria are described in Sec.2 to Sec.4.

For structures such as hatch covers, ramps etc., it will in general be sufficient to carry out a direct frame and girder analysis as described in Ch.6 Sec.6 [2].