Weld assessments using FEM
The Finite Element Method (FEM) is a commonly used tool for structural analysis.
Despite this, it is difficult to find practical guidelines on how to build and evaluate the results from FE models of welded structures subjected to fatigue loads.
The purpose of the course is to provide such practical guidelines for how loading conditions, design of FE models, element selection, and evaluation methods should be chosen, managed and assessed. The course includes several examples and suggestions for appropriate modeling and evaluation methods.
In addition, several calculation standards in the field are compared, and the suitability of using these standards in FE analyses is discussed.
Course participants who wish to discuss their own design problems or analyze their own loading spectra are encouraged to submit them well before the start of the course, in order to use them as discussion material during the course.
Prerequisites: The course is intended for analysis and design engineers who work daily with FEM, possess strong general knowledge of structural mechanics, and have experience with EC3, EN 13001, DNV, IIW recommendations, or equivalent standards.
Program:
Day 1: General introduction to fatigue and FE analyses of welded structures.
- Fatigue of welded structures: Basic principles focused on FEM-based analysis.
- Evaluation methods: Brief overview.
- Modeling and element selection: When, where, and how to choose between beam,
shell, and solid elements? Substructures, boundary conditions, MPCs,
symmetry/antisymmetry.
- Quality assurance of FE analyses, handling of singular points in FE-models.
Day 2: Evaluation methods.
- In-depth look at modeling and evaluation methods: Nominal stress, Hot Spot method,
and Effective Notch method.
- Shell elements or solid elements? Tips, advices, and warnings.
- Distribution of practice examples.
Day 3: Application of methods.
- Solving practice examples.
- Fracture mechanics analysis of welded joints.
- Optimal weld throat size: How to analyze and optimize the throat size of fillet welds?
- Welded joints subjected to static loads / design for maximum loads in a load spectrum.
Day 4: Standards, life estimations, and multiaxial stresses
- Possibility of using different standards in FE analyses: Eurocode 3, EN 13001, DNVGL
and IIW recommendations are discussed.
- Life estimations in connection with FE analyses, sensitivity analyses.
- Multiaxial stresses in connection with FE analyses.
- Discussion on advantages/disadvantages of different evaluating methods.
- Supplementary literature and recommendations for further study.