![Results
RATIO (b/a) ANSYS SCF THEROTICAL SCF [Ref4]
1 circular hole 3.76 3
. . .
. . .
0.75 4.44 3.66
. . .
. . .
0.5 5.8628 5
. . .
. . .
0.25
. . .
. . .
0.02 Flat Elliptical Hole 110.83 101](https://image.slidesharecdn.com/final-121029054741-phpapp02/85/Revisiting-Inglis-Theory-in-Finite-Element-Analysis-and-ANSYS-15-320.jpg)
Revisiting Inglis Theory in Finite Element Analysis and ANSYS
- 1. REVISITING INGLIS THEORY BASED ON FINITE ELEMENT METHOD Presented by, Sachin shewale Sanket kasar Amey Deshpande Under the guidance of, Mr.Vinay Patil
- 2. Background of the presentation • Project deals with calculation of SIF under influence of various parameters. • SIF is the concept evolved during the development of fracture mechanics. • Fracture mechanics treats crack as a discontinuity and early work on discontinuity is related with stress concentration factor.
- 3. Evolution of SCF • Leonardo Da Vinci proposed flaws to be the root cause of failure. • Presence of flaw in a material focuses the stress at particular portion and this stress concentration causes failure. • This concept was extended by Inglis giving a mathematical formula for stress concentration factor.
- 4. Mathematical model for elliptical hole developed by Inglis • Inglis approximated crack as an extremely flat ellipse. • His analysis began with circular hole and then compressing it to form an ellipse . Fig. Elliptical hole in flat plate
- 5. Inadequate Meshing PROBLEM SOLUTION MESHING
- 6. Improved Meshing Since we are more concerned about stress distribution at the vicinity of circular hole, ring is modeled around the hole and regular mesh is generated in that ring zone as shown in fig. Sec A-A Section A-A Fine mesh Zoomed view of sec A-A
- 10. Flow chart of If-Do loop start C=number of refinements yes Is C=0 Exit No i=1 C=1 C=2 yes erefine, all do No i=i+1 IsIs i>C C=3
- 11. Genuine peak plot Genuine peak
- 12. Predicted Peak Predicted peak value = 39.544 MPa 35.846 2.21 1/2.2 38.056 0.999 1/2.8 39.055 0.357 1/3.4 39.412 0.105 1/4 39.517 0.027
- 13. ANSYS Plot σ ( y)max (SCF)ansys= (σy)max/ (σ)applied = 18.8/5 = 3.76
- 14. Team Work • 6 Engineers • Time Span of 14 days • No. of Analysis = 400
- 15. Results RATIO (b/a) ANSYS SCF THEROTICAL SCF [Ref4] 1 circular hole 3.76 3 . . . . . . 0.75 4.44 3.66 . . . . . . 0.5 5.8628 5 . . . . . . 0.25 . . . . . . 0.02 Flat Elliptical Hole 110.83 101
- 16. Graph showing variation in SCF
- 17. VARIATION IN ANSYS AND THEROTICAL VALUES? • Theoretical stress values Engg. Stress Engg. Stress = Applied Load/Area • ANSYS stress values True Stress True Stress = Applied Load/Instantaneous Area
- 18. Estimated value for sigma y
- 19. Conclusion
- 20. • From the graph value of stress at x=0, is 12360 MPa it is clearly shows that estimated values of Stress in y direction are increasing as we collapse circle to ellipse to form crack . • Hence reaching stress singularity and our work is correlating with Inglis theory.
- 21. Future work • 2-D crack modelling and SIF calculation. • 2-D Inclined crack modelling and SIF calculation. • 3-D crack modelling and SIF calculation • 3-D Inclined crack modelling and SIF calculation.(if time permits). • Crack Tip Plasticity.
- 22. THANK YOU