3D Analysis of Crack Behavior Using XFEM

2015 ◽  
Vol 789-790 ◽  
pp. 278-281
Author(s):  
Sung Hyun Lee ◽  
Insu Jeon
Keyword(s):  
Crack Growth ◽  
Model Simulation ◽  
Fe Model ◽  
3D Analysis ◽  
Ideal Model ◽  
The Real ◽  
Crack Behavior ◽  
Growth Test ◽  
Real Model ◽  
3D Crack Growth

It is important to evaluate the 3D crack behavior in the structures. In this study, a Crack-growth test and two simulations namely, Real-model simulation and Ideal-model simulation were performed using eXtended Finite Element Method (XFEM) to evaluate crack behavior three-dimensionally. In the Crack-growth test, crack behavior was observed for a notched metal specimen. In the Real-model simulation, the FE model was constructed using a 3D reconstruction model of the specimen, and crack growth was simulated. In the Ideal-model simulation, the simulation was performed using the FE model that involved ideal notch. The obtained crack growth simulation results were compared with tension test result. Crack growth in the specimen was evaluated three-dimensionally. It was shown that modeling the real shape of a structure with a crack may be essential for accurately evaluating 3D crack growth.

Comparison of Computational Crack Path Predictions with Experimental Findings for a Quarter-Circular Surface Crack in a Shaft under Torsion

2007 ◽  
Vol 348-349 ◽  
pp. 161-164 ◽  
Author(s):  
Friedrich G. Buchholz ◽  
J. Wiebesiek ◽  
M. Fulland ◽  
Hans A. Richard
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Front ◽  
Fracture Criterion ◽  
Circular Crack ◽  
Fe Model ◽  
Crack Growth Behaviour ◽  
3D Crack Growth ◽  
Experimental Findings

In this paper the rather complex 3D fatigue crack growth behaviour in a shaft with a quarter-circular crack under torsion is investigated by the aid of the programme ADAPCRACK3D and by application of a recently developed 3D fracture criterion. It will be shown that the computationally simulated results of fatigue crack growth in the FE-model of the shaft are in good agreement with experimental findings for the development of two anti-symmetric cracks, which originate from the two crack front corner points, that is where the crack front intersects the free surface of the cylindrical laboratory test-specimens. Consequently, also for this case with a rather complex 3D crack growth of two anti-symmetric cracks, the functionality of the ADAPCRACK3Dprogramme and the validity of the proposed 3D fracture criterion can be stated.

Comparison of DBEM and FEM Crack Path Predictions with Experimental Findings for a SEN-Specimen under Anti-Plane Shear Loading

2007 ◽  
Vol 348-349 ◽  
pp. 129-132 ◽  
Author(s):  
Roberto G. Citarella ◽  
Friedrich G. Buchholz
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Front ◽  
Crack Path ◽  
Shear Loading ◽  
Crack Growth Behaviour ◽  
3D Crack Growth ◽  
Corner Points ◽  
Experimental Findings

In this paper detailed results of computational 3D fatigue crack growth simulations will be presented. The simulations for the crack path assessment are based on the DBEM code BEASY, and the FEM code ADAPCRACK 3D. The specimen under investigation is a SEN-specimen subject to pure anti-plane or out-of-plane four-point shear loading. The computational 3D fracture analyses deliver variable mixed mode II and III conditions along the crack front. Special interest is taken in this mode coupling effect to be found in stress intensity factor (SIF) results along the crack front. Further interest is taken in a 3D effect which is effective in particular at and adjacent to the two crack front corner points, that is where the crack front intersects the two free side surfaces of the specimen. Exactly at these crack front corner points fatigue crack growth initiates in the experimental laboratory test specimens, and develops into two separate anti-symmetric cracks with complex shapes, somehow similar to bird wings. The computational DBEM results are found to be in good agreement with these experimental findings and with FEM results previously obtained. Consequently, also for this new case, with complex 3D crack growth behaviour of two cracks, the functionality of the proposed DBEM and FEM approaches can be stated.

Surrogate modeling of 3D crack growth

2013 ◽  
Vol 47 ◽  
pp. 90-99 ◽  
Author(s):  
V.K. Hombal ◽  
S. Mahadevan
Keyword(s):  
Crack Growth ◽  
Surrogate Modeling ◽  
3D Crack Growth

System Identification and Pseudo-Earthquake Excitation of a Real-Scaled 5 Story Steel Frame Structure

2008 ◽  
Author(s):  
Eunchurn Park ◽  
Sang-Hyun Lee ◽  
Sung-Kyung Lee ◽  
Hee-San Chung ◽  
Kyung-Won Min
Keyword(s):  
System Identification ◽  
Forced Vibration ◽  
Structural Information ◽  
Frame Structure ◽  
Fe Model ◽  
Building Structure ◽  
Earthquake Excitation ◽  
Accurate Identification ◽  
The Real ◽  
Response Characteristics

The accurate identification of the dynamic response characteristics of a building structure excited by input signals such as real earthquake or wind load is essential not only for the evaluation of the safety and serviceability of the building structure, but for the verification of an analytical model used in the seismic or wind design. In the field of system identification (SI) which constructs system matrices describing the accurate input/output relationship, it is critical that input should have enough energy to excite fundamental structural modes and a good quality of output containing structural information should be measured. In this study forced vibration testing which is important for correlating the mathematical model of a structure with the real one and for evaluating the performance of the real structure was implemented. There exist various techniques available for evaluating the seismic performance using dynamic and static measurements. In this paper, full scale forced vibration tests simulating earthquake response are implemented by using a hybrid mass damper. The finite element (FE) model of the structure was analytically constructed using ANSYS and the model was updated using the results experimentally measured by the forced vibration test. Pseudo-earthquake excitation tests showed that HMD induced floor responses coincided with the earthquake induced ones which was numerically calculated based on the updated FE model.

scholarly journals Creep Crack Growth Test Method and Creep Crack Growth Properties for TiAl Intermetallic Compound.

2000 ◽  
Vol 49 (1) ◽  
pp. 80-85 ◽  
Author(s):  
Masaaki TABUCHI ◽  
Toshimitu YOKOBORI ◽  
Akio FUJI ◽  
Kiyoshi KUBO ◽  
Koichi YAGI ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
Crack Growth ◽  
Creep Crack Growth ◽  
Test Method ◽  
Creep Crack ◽  
Growth Test ◽  
Tial Intermetallic Compound ◽  
Growth Properties

scholarly journals 3D Finite Element Model Simulating the Behaviour of Filling Soils Used to Set Up a New Placement Method for Separate Sewer Systems

2019 ◽  
Vol 8 (3) ◽  
pp. 87-98
Author(s):  
Alaa Abbas ◽  
Felicite Ruddock ◽  
Rafid Alkhaddar ◽  
Glynn Rothwell ◽  
Iacopo Carnacina ◽  
...  
Keyword(s):  
Finite Element ◽  
Soil Properties ◽  
Model Simulation ◽  
New Method ◽  
Traffic Load ◽  
Scale Model ◽  
Fe Model ◽  
Fe Method ◽  
Buried Pipes ◽  
The Impact

The use of a finite element (FE) method and selection of the appropriate model to simulate soil elastoplastic behaviour has confirmed the importance and sensitivity of the soil properties on the accuracy when compared with experimental data. The properties of the filling soil play a significant role in determining levels of deformation and displacement of both the soil and subterranean structures when using the FE model simulation. This paper investigates the impact of the traffic load on the filling soil deformation when using the traditional method, one pipe in a trench, and a new method, two pipes in a single trench one over the other, for setting up a separate sewer system. The interaction between the buried pipes and the filling soils has been simulated using an elastoplastic FE model. A modified Drucker–Prager cap constitutive model was used to simulate the stress-strain behaviours of the soil. A series of laboratory tests were conducted to identify the elastoplastic properties of the composite soil used to bury the pipes. The FE models were calibrated using a physical lab model for testing the buried pipes under applied load. This allows the FE model to be confidently upgraded to a full-scale model. The pipe-soil interactions were found to be significantly influenced by the soil properties, the method of placing the pipes in the trench and the diameters of the buried pipes. The deformation of the surface soil was decreased by approximately 10% when using the new method of setting up the separate sewer.

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