Компьютерное моделирование разрушения твердого аргона

• Автор: Горги Наджах Юсиф
• Шифр специальности: 01.04.07
• Научная степень: Кандидатская
• Год защиты: 2000
• Место защиты: Барнаул
• Количество страниц: 165 с. : ил.

Contents
Introduction
Chapter One
1.1. From the history of fracture
1.2. Macroscopic and microscopic view of fracture
1.3. Fracture modes
1.4. Review of experimental fracture studies
1.5. Finite element method
1.6. Atomistic computer simulation
1.7. Review of computer simulation of fracture studies
1.8. Mixed fracture modes
Chapter Two
2. The computer simulation model
Chapter Three
3.1. Computer simulation fracture experiments under tension
deformation (mode I)
3.1.1. Deformation interval from 0 to 15%
3.1.2. Deformation equal to the 15%
3.1.3. Deformation equal to the 20%
3.1.4. Deformation equal to the 28%
3.1.5. Deformation equal to the 34%
3.2. Observations of the full fracture mode I process stages
3.3. Computer simulation under mixed mode loading (I+II)
3.3.1 Applied deformation ratio (si/sn) is <1
3.3.1.1. The simulation result at applied deformation ratio equal to
3.3.1.2. The simulation result at applied deformation ratio equal to
3.3.1.3. The simulation result at applied deformation ratio equal to
3.3.2. Applied deformation ratio (si/sn) is >1
3.3.2.1. The simulation result at applied deformation ratio equal to
3.3.2.2. The simulation result at applied deformation ratio equal to
3.3.2.3. The simulation result at applied deformation ratio equal to
3.4. Fracture simulations of crystal with different crack distance
3.4.1. Crack length equal to 10 atomic spacings
3.4.2. Crack length equal to 30 atomic spacings
3.4.3. Crack length equal to 10 atomic spacings
3.4.4. Crack length equal to 10 atomic spacings
Conclusion
Reference

Fracture studies in solid Ar using computer simulation
One of the most important and key concepts in the entire field of materials science and engineering is fracture. Research efforts in the field of fracture mechanics since early 1950’s have resulted in many applications and use of many parameters to predict the instability condition in a wide spectrum of materials under the influence of load.
Fracture is a very complex process which involves the nucleation and growth of dislocations, micro and macro voids and cracks. From the point of view of mechanics, fracture in its simplest definition; a single body begins to separate into pieces by an imposed stress. From the point of view of microscopic focus, fracture is simply the breaking of atomic bonds between atoms.
For analytical purpose a crack line has been idealized as one-dimensional defect on a flat cleavage plane. That is why there are three modes of cracks corresponding to the different orientations of external stress with respect to the fracture plane and they are distinguished by indices I, II and III.
Many research efforts have been confined to investigation and understanding of both materials and structure response under a mode I loading condition. However, in practice, materials are often subjected to either a mode I/II or mode I/III loading.
As the fracture in materials is very complex process and diverse, it is

Fig.5. Undeformed crystal model, consisting of a crack