Integrity Evaluation for 3D Cracked Structures(II)

Three Surface cracks are among the more common flaws in aircraft and pressure vessel components. Accurate stress intensity analyses and crack growth rate data of surface-cracked components are needed for reliable prediction of their fatigue life and fracture strengths. Three Dimensional finite element method (FEM) was used to obtain the stress intensity factor for surface cracks existing in structures. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Nodes are generated by bucket method, and quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. To examine accuracy and efficiency of the present system, the stress intensity factor for a semi-elliptical surface crack in cylindrical structures subjected to pressure is calculated. Analysis results by present system showed good agreement with those by ASME equation and Raju-Newman`s equation.

[1]  S. Lo.  A NEW MESH GENERATION SCHEME FOR ARBITRARY PLANAR DOMAINS , 1985 .

[2]  Joon-Seong Lee,et al.  Fracture analysis for ceramic disk with semi-elliptical crack and pore , 2014 .

[3]  Hiroshi Noguchi,et al.  Tension of a finite-thickness plate with a pair of semi-elliptical surface cracks , 1990 .

[4]  James C. Newman,et al.  Stress-Intensity Factors for Internal and External Surface Cracks in Cylindrical Vessels , 1982 .

[5]  李準晟.  Automated CAE System for Three-Dimensional Complex Geometry(3次元複雑形状の自動CAEシステム) , 1995 .

[6]  Sang-Log Kwak,et al.  Probabilistic Integrity Assessment of Axial Flaw in CANDU Pressure Tube Due to the Diameter and Thickness Variation , 2002 .

[7]  Albert S. Kobayashi,et al.  Stress intensity factor for an elliptical crack under arbitrary normal loading , 1971 .

[8]  William H. Frey,et al.  An apporach to automatic three‐dimensional finite element mesh generation , 1985 .

[9]  D. F. Watson.  Computing the n-Dimensional Delaunay Tesselation with Application to Voronoi Polytopes , 1981, Comput. J..

[10]  Moon-Jung Kim,et al.  The Korea Academia-Industrial cooperation Society , 2012 .

[11]  M. Iri,et al.  Practical use of Bucketing Techniques in Computational Geometry , 1985 .

[12]  James C. Newman,et al.  Stress-intensity factors for a wide range of semi-elliptical surface cracks in finite-thickness plates , 1979 .

[13]  Tony C. Woo,et al.  AN ALGORITHM FOR GENERATING SOLID ELEMENTS IN OBJECTS WITH HOLES , 1984 .

[14]  Joon-Seong Lee,et al.  Domain Decomposition Method for Elasto-Plastic Problem , 2011 .

[15]  Joon-Seong Lee,et al.  Automatic Mesh Generation System for FE Analysis of 3D Crack , 2009 .