Department News
Cracks, Crack Propagation, and Simulations of Fracture in the Material Point
Seminar Date
2004-11-01
Author
임아주
Date
2004-11-01
Views
1758
1. 제 목 : Cracks, Crack Propagation, and Simulations of Fracture in the Material Point
Method
2. 연 사 : Professor John A. Nairn (University of Utah)
3. 일 시 : 2004년 11월 10일 (수) 16:30 ~ 17:30
4. 장 소 : 301동 1512호 세미나실
5. 내 용 :
The material point method (MPM) has recently been developed as a numerical method for solving problems in dynamic solid mechanics. MPM is a particle-based method that uses a background grid as mathematical scratch pad. Despite the use of a grid, MPM has more in common with meshless methods than it does with finite element analysis. We have recently extended MPM to handle explicit cracks in a new algorithm called CRAMP or “CRAcks with Material Points.” This new method has several advantages for numerical work on fracture. Compared to finite element analysis, CRAMP can handle cracks with similar algorithmic efficiency, but is better at handling crack surface contact and crack propagation in arbitrary directions. Compared to meshless methods, CRAMP can handle arbitrary crack propagation with similar ease, but is better at inclusion of explicit cracks. MPM/CRAMP also works well for calculating key fracture parameters such as J integral, stress intensity factors, or crack-opening displacements. The background grid in MPM was an important tool in fracture modeling. The grid facilitated the “exact” algorithmic inclusion of explicit cracks and the efficient calculation of fracture parameters. This talk will summarize the approach of the MPM/CRAMP method and illustrates it with several example calculations including 2D and 3D crack propagation.
Another application of MPM for fracture problems is an attempt to develop a new approach to numerical work on crack growth called “Fracture Simulations.” The difference between a fracture simulation and a more traditional fracture calculation is that a simulation attempts to model crack growth by an energy balance condition including all needed energy terms rather than by satisfaction of a specified failure criterion. In other words, there is no input of a fracture toughness into a simulation. Instead, the output of a simulation will be the energy dissipation that occurred during crack growth in the computer experiment. One application of fracture simulations is to study non-material effects on crack growth such as the effect of adhesive thickness on toughness or scaling effects in nanocomposite fracture.
6. 연사 경력 : Ph.D., Chemistry, University of California, Berkeley, 1981
B.A., Chemistry, Dartmouth College, 1977
7. 문 의: 기계항공공학부 조 맹 효 교수 (☎ 880-1693)
Method
2. 연 사 : Professor John A. Nairn (University of Utah)
3. 일 시 : 2004년 11월 10일 (수) 16:30 ~ 17:30
4. 장 소 : 301동 1512호 세미나실
5. 내 용 :
The material point method (MPM) has recently been developed as a numerical method for solving problems in dynamic solid mechanics. MPM is a particle-based method that uses a background grid as mathematical scratch pad. Despite the use of a grid, MPM has more in common with meshless methods than it does with finite element analysis. We have recently extended MPM to handle explicit cracks in a new algorithm called CRAMP or “CRAcks with Material Points.” This new method has several advantages for numerical work on fracture. Compared to finite element analysis, CRAMP can handle cracks with similar algorithmic efficiency, but is better at handling crack surface contact and crack propagation in arbitrary directions. Compared to meshless methods, CRAMP can handle arbitrary crack propagation with similar ease, but is better at inclusion of explicit cracks. MPM/CRAMP also works well for calculating key fracture parameters such as J integral, stress intensity factors, or crack-opening displacements. The background grid in MPM was an important tool in fracture modeling. The grid facilitated the “exact” algorithmic inclusion of explicit cracks and the efficient calculation of fracture parameters. This talk will summarize the approach of the MPM/CRAMP method and illustrates it with several example calculations including 2D and 3D crack propagation.
Another application of MPM for fracture problems is an attempt to develop a new approach to numerical work on crack growth called “Fracture Simulations.” The difference between a fracture simulation and a more traditional fracture calculation is that a simulation attempts to model crack growth by an energy balance condition including all needed energy terms rather than by satisfaction of a specified failure criterion. In other words, there is no input of a fracture toughness into a simulation. Instead, the output of a simulation will be the energy dissipation that occurred during crack growth in the computer experiment. One application of fracture simulations is to study non-material effects on crack growth such as the effect of adhesive thickness on toughness or scaling effects in nanocomposite fracture.
6. 연사 경력 : Ph.D., Chemistry, University of California, Berkeley, 1981
B.A., Chemistry, Dartmouth College, 1977
7. 문 의: 기계항공공학부 조 맹 효 교수 (☎ 880-1693)
