FSD3400 Advanced Design of Welded Joints 6.0 credits

This course discuss different advanced methods for fatigue design of welded structures; Nominal stress method, Hot Spot (geometric/structural) Stress method, Effective Notch Stress method and applied linear elastic fracture mechanics (LEFM).  Influence of different factors that effect the fatigue life and breakdown is discussed, such as; stress concentrations, weld defects, welding residual stresses, multiaxial  stresses, etc.. Different post weld improvement  techniques in order to increase the quality and the fatigue strength of welded structures is discussed. Different weld class system in order to assure the weld quality of welded joints in the design and during production is discussed and compared.  Different design codes, guidelines for practice and recommendations for welded jonits are discussed e.g. IIW:s “recommendations for fatigue design of welded jonits and components”.  Evaluation and fatigue design of welded structures using FEM is treated regarding; boundary conditions, accuracy, non-linearity, sub-modelling techniques, 3D effects. Different state-of-the-art applied fracture mechanical softwares for prediction of  the fatigue life of welded jonits is presented, discussed and utilized.

FEM (ANSYS), Linear elastic fracture mechanics (LEFM) and basic knowledge in solid mechanics, material mechanics and fatigue.

Ett för ändamålet nyskrivet kurskompendium kommer att delas ut. Utdelade artiklar. Utdrag ur standarder, koder och normer. Rekommendation av litteratur för ytterligare studier kommer att meddelas vid kursstart.

A special written course compendium will be handed out. Extract from Articles, standard and design codes will be handed out. Recommended literature for further reading will be announced at the course start.

If the course is discontinued, students may request to be examined during the following two academic years.

• INL1 - Assignment, 3.0 credits, grading scale: G
• LAB1 - Laboratory work, 3.0 credits, grading scale: G

Based on recommendation from KTH’s coordinator for disabilities, the examiner will decide how to adapt an examination for students with documented disability.

The examiner may apply another examination format when re-examining individual students.

3 exercises on fatigue design with FEM: examination; results presented at the lab occasion.

1 extended home assignment/casestudy: fatigue design of welded structures: examination; written report.

2 extended home assignment in fatigue design of welded structures using LEFM and FEM: examination; written report.

Zuheir Barsoum

• All members of a group are responsible for the group's work.
• In any assessment, every student shall honestly disclose any help received and sources used.
• In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.