ANALYSIS OF DYNAMIC STRESS INTENSITY FACTORS FOR CRACKED STIFFENED PLATES BASED ON EXTENDED FE METHOD

2021 ◽  
Vol 162 (A1) ◽  
Author(s):  
Y Peng ◽  
P Yang
Keyword(s):  
Stress Intensity ◽  
Crack Length ◽  
Stress Intensity Factors ◽  
Dynamic Stress ◽  
Mesh Size ◽  
Stiffened Plates ◽  
Intensity Factors ◽  
Time Step ◽  
Dynamic Stress Intensity Factors ◽  
Crack Location

The dynamic stress intensity factors (DSIFs) for cracked stiffened plates considering the actual boundary conditions in ship structures are analyzed by the extended finite element method (XFEM). The sensitivity of numerical results with respect to mesh size and time step is discussed. Some other influential parameters including stiffener height, crack location and crack length are also analyzed. The numerical results show that the convergence is affected by mesh size and time step. By using XFEM, singular elements are not needed at the crack front and moderately refined meshes can achieve good accuracy. The height of the stiffener and crack location significantly effect DSIFs, while the crack length slightly influences the DSIFs.

Analysis of Dynamic Stress Intensity Factors for Cracked Stiffened Plates Based on Extended FE Method

2020 ◽  
Vol 162 (A1) ◽  
Author(s):  
Y Peng ◽  
P Yang
Keyword(s):  
Stress Intensity ◽  
Crack Length ◽  
Stress Intensity Factors ◽  
Dynamic Stress ◽  
Mesh Size ◽  
Stiffened Plates ◽  
Intensity Factors ◽  
Time Step ◽  
Dynamic Stress Intensity Factors ◽  
Crack Location

The dynamic stress intensity factors (DSIFs) for cracked stiffened plates considering the actual boundary conditions in ship structures are analyzed by the extended finite element method (XFEM). The sensitivity of numerical results with respect to mesh size and time step is discussed. Some other influential parameters including stiffener height, crack location and crack length are also analyzed. The numerical results show that the convergence is affected by mesh size and time step. By using XFEM, singular elements are not needed at the crack front and moderately refined meshes can achieve good accuracy. The height of the stiffener and crack location significantly effect DSIFs, while the crack length slightly influences the DSIFs.

Elastodynamic Fracture Analysis of Multiple Cracks by Laplace Finite Element Alternating Method

1999 ◽  
Vol 67 (3) ◽  
pp. 606-615 ◽  
Author(s):  
W.-H. Chen ◽  
C.-L. Chang ◽  
C.-H. Tsai
Keyword(s):  
Finite Element ◽  
Stress Intensity ◽  
Laplace Transform ◽  
Stress Intensity Factors ◽  
Dynamic Stress ◽  
Multiple Cracks ◽  
Intensity Factors ◽  
Dynamic Stress Intensity Factors ◽  
Alternating Method ◽  
The Laplace Transform

The Laplace finite element alternating method, which combines the Laplace transform technique and the finite element alternating method, is developed to deal with the elastodynamic analysis of a finite plate with multiple cracks. By the Laplace transform technique, the complicated elastodynamic fracture problem is first transformed into an equivalent static fracture problem in the Laplace transform domain and then solved by the finite element alternating method developed. To do this, an analytical solution by Tsai and Ma for an infinite plate with a semi-infinite crack subjected to exponentially distributed loadings on crack surfaces in the Laplace transform domain is adopted. Finally, the real-time response can be computed by a numerical Laplace inversion algorithm. The technique established is applicable to the calculation of dynamic stress intensity factors of a finite plate with arbitrarily distributed edge cracks or symmetrically distributed central cracks. Only a simple finite element mesh with very limited number of regular elements is necessary. Since the solutions are independent of the size of time increment taken, the dynamic stress intensity factors at any specific instant can even be computed by a single time-step instead of step-by-step computations. The interaction among the cracks and finite geometrical boundaries on the dynamic stress intensity factors is also discussed in detail. [S0021-8936(00)02103-6]

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