Overview

The welding process involves complex interaction of several mechanisms. The fundamental understanding relied on basic mechanisms such as heat transfer and/or fluid flow, and associated distortion and residual stress generation including the effect of metallurgical transformation for a welding process is the focus of this course. It helps to develop the numerical model, and makes the foundation for analysis and experimentation for the process. The development of computational models for welding process relies on mathematical expression of the governing mechanism. It helps to design relevant experiments and drives to find the data to be obtained. Mutual understanding between numerical and experimental results leads to better insight of the welding processes that impact on the improvement of existing process and directs to the development of new process. This course emphasized on the development of finite element based numerical model of both fusion and solid state welding processes. The development of FE-based model is presented in a simplified way to understand the subject at elementary level. The broad impact is that the students will be able to develop FE-based heat transfer, fluid flow and stress analysis model of welding process using standard commercial package. However, this course does not intend to cover the learning of the commercial software.INTENDED AUDIENCE :Bachelor/Master/PhD students having background in Mechanical/Material Science/Metallurgical engineering/ Production Engineering/Manufacturing Technology The faculty of different institutes can attend this course as a part of FDP.PREREQUISITES : NoneINDUSTRIES SUPPORT :None

Syllabus

Week 1-2:Introduction to welding processes
Classification, fusion welding, brazing and soldering, solid state welding processes, advanced welding processes, wire additive manufacturing processes Week 3-4: Fundamentals of finite element (FE) method
Elastic stress Analysis, Weighted residue technique, Material non-linearity, Heat conduction, Fluid flow, Structure of a FE model, Steps of a FE model,
Introduction FE solver, X-FEM and other interface tracking methods Week 5: Heat source model in conduction mode welding processes
Representation of heat source, Surface heat source model, Volumetric heat source model, Heat source model for solid state welding, Heat source model for keyhole mode laser and electron beam welding processes Week 6-7:Application of FEM to model welding processes
Fusion welding: laser, arc, electron beam and resistance spot Solid state welding: Friction, FSW and hybrid FSW Representation of welding processes by governing equations and boundary conditions, Incorporation of heat source, Difference between linear and spot welding, FE formulation, Incorporation of temperature dependent properties, Incorporation of latent heat of melting and solidifications
Demonstration of thermal model development using commercial software Week 8:FE-based fluid flow model in fusion welding processes
Surface active elements and fluid flow, Allied welding processes, Governing equations and boundary conditions, FE formulation, Solution strategy, Prediction of free surface profile
Week 9:FE-based elastic-plastic stress model of welding processes

Yield criteria, Hardening rule, Flow rule, Material models, FE formulation, Prediction of residual stress and distortion, Solution strategy, Incorporation of phase transformation effect
Demonstration of thermo-mechanical model development using commercial software Week 10:FE model of metal transfer in welding
Fundamentals of metal transfer in arc welding, FE-based modelling approaches Week 11:FE model of non-Fourier heat conduction
Ultra short pulse laser welding, Heating of nano-film, lattice distortion Week 12:FE model of wire-additive manufacturing processes
Fundamentals of wire additive manufacturing processes, Modelling approaches of additive manufacturing, FE formulation, Solution strategy