Training Programme on FE Analysis …

1. Training Programme on FE Analysis … DAY - 1: Introduction to Structural Analysis and FEM DAY - 2: Introduction to ANSYS structure classic GUI: DAY - 3: Pre-processing and creation of model: DAY - 4: Pre-processing and creation of model DAY - 5: Analysis result and post-processing: DAY - 6: Analysis result and post-processing

2. Introduction to Finite Element Analysis Presented by – Rakesh Roy

3. Layout • What is FEA ?? • Theory behind FEA • Types of FEA or Usage • Working with FEA tools • Advantage/Limitations of FEA • Scope in Marine & Offshore industry

4. Engineering Problem Solving

5. Structural Problem Solving

6. FEA… Finite Element Analysis • Finite element method – approximates the physics - numerical procedure for solving a continuum mechanics problem with acceptable accuracy • Subdivide a large problem into small elements connected by nodes • Adjacent element share DOF at connecting nodes

7. FEA… Theory • Assume a simple polynomial behavior in each element • Works on equilibrium at nodes → matrix equations →solve for nodal values (disp.)

8. DOF… Degree of Freedom • DOF = Elemental Degrees of Freedom (typically 2 – 6 depending on the element) • 2D Bar/Spar/Truss = 2 Node, 2 DOF (Translation) • Spring = 2 Node, 2 DOF (1 Translational + 1 Rotational) • 3D Beam = 3 Node, 6 DOF (3 Translational + 3 Rotational) • Shell4 = 4 Node, 6 DOF (3 Translational + 3 Rotational) • Solid = (8 – 20 Node) 3 DOF (3 Translational)

9. Types of FEA • Linear (small displacement, linear materials) • Nonlinear (large displacement, nonlinear material properties) • Static or yield stress analysis • Linear or nonlinear Dynamics • Frequency analysis • Random vibration analysis • Buckling • Thermal and heat transfer • Fluid mechanics • Electromagnetics • Optimization

10. Working with FEA tools..

11. Preprocessor…

12. Preprocessor….

13. Process & Postprocessor….

14. Advantage of FEA • Can handle very complex geometry – the power of FEM • Can handle wide variety of engineering problems with inter-dependency • Solid mechanics • Dynamics • Heat problems • Fluids • Electrostatic problems • Can handle complex restraints – indeterminate structures • Can handle complex loading • Nodal load (point load) • Element load (pressure, thermal, inertia) • Time or frequency dependent loading

15. Limitations of FEA • Approximate Solution • Field quantities are assumed to be polynomial, which is not true

16. Limitations of FEA • Finite number of digits • Numerical difficulties – very large stiffness difference

17. Possible mistakes by user • Wrong element selection • Distorted elements or meshing problem • Insufficient support/improper boundary condition • Inconsistent units (e.g. E=200GPa, Force= 1 lbs) • Decoding the result – fancy, colourful result but wrong

18. Scope in Marine industry.. • Complex structures • Impossible to make prototype • Difficult to scale down all details to model level • Complex problem… non-linear load, heat, fluid, vibration • Huge cost advantage with reduction in material (optimisation)

19. Stress analysis…Global • Global hull • 3 Cargo Hold • Offshore structure • MODU • Jacket Leg Structure

20. Stress analysis… local • Foundation of heavy equipment • Crane • Helideck • Windlass • Offshore • Top side foundations • Pipe line • Drilling unit

21. Special analysis… • Buckling • Rupture/Failure Analysis • Vibration/Modal analysis • Impact Analysis • Fatigue

22. Fluid Structure Interaction… FSI • Slamming • Sloshing • Propeller Induced load

23. In short… Marine design can’t live without FEA

24. THANK YOU