Section 1 Introduction
Clasification Society 2024 - Version 9.40
Clasifications Register Guidance Information - Guidance Notes for the Calculation of Stress Concentration Factors, Fatigue Enhancement Methods and Evaluation of Fatigue Tests for Crankshafts, July 2021 - Chapter 4 Guidance for Calculation of Stress Concentration Factors in the Oil Bore Outlets of crankshafts through utilisation of the Finite Element Method - Section 1 Introduction

Section 1 Introduction

Parent topic: Chapter 4 Guidance for Calculation of Stress Concentration Factors in the Oil Bore Outlets of crankshafts through utilisation of the Finite Element Method

1.1 General

1.1.1 The objective of the analysis described in this document is to substitute the analytical calculation of the stress concentration factor (SCF) at the oil bore outlet with suitable finite element method (FEM) calculated figures. The former method is based on empirical formulae developed from strain gauge readings or photo-elasticity measurements of various round bars. Because use of these formulae beyond any of the validity ranges can lead to erroneous results in either direction, the FEM-based method is highly recommended.

1.1.2 The SCF calculated according to the rules set forth in this document is defined as the ratio of FEM-calculated stresses to nominal stresses calculated analytically. In use in connection with the present method in Pt 5, Ch 2, 3 Crankshaft Design of the Rules and Regulations for the Classification of Ships, July 2022, principal stresses shall be calculated.

1.1.3 The analysis is to be conducted as linear elastic FE analysis, and unit loads of appropriate magnitude are to be applied for all load cases.

1.1.4 It is advisable to check the element accuracy of the FE solver in use, e.g. by modelling a simple geometry and comparing the FEM-obtained stresses with the analytical solution.

1.1.5 A boundary element method (BEM) approach may be used instead of FEM.

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