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fracture mechanics analysis on Smart-Cut~ technology.Part 1:Effects of stiffening wafer and defect interaction

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Acta Mechanica Sinica 2009年第1期25卷 73-81页

作者： Bin Gu Hongyuan Liu Yiu-Wing Mai Xi Qiao Feng Shou Wen Yu Centre for Advanced Materials Technology (CAMT) School of Aerospace Mechanical and MechatronicEngineering (AMME) J07 University of SydneySydney NSW 2006 Australia Department of Engineering mechanics Tsinghua University 100084 Beijing China

In the present paper, continuum fracture mechanics is used to analyze the Smart-Cut process, a recently established ion cut technology which enables highly efficient fabrication of various silicon-on-insulator （SOI） wafers of high uniformity in thickness. Using integral transform and Cauchy singular integral equation methods, the mode-I and mode-II stress intensity factors, energy release rate, and crack opening displacements are derived in order to examine several important fracture mechanisms involved in the Smart-Cut process. The effects of defect interaction and stiffening wafer on defect growth are investigated. The numerical results indi- cate that a stiffener/handle wafer can effectively prevent the donor wafer from blistering and exfoliation, but it slows down the defect growth by decreasing the magnitudes of SIF＇s. Defect interaction also plays an important role in the splitting process of SOI wafers, but its contribution depends strongly on the size, interval and internal pressure of defects. Finally, an analytical formula is derived to estimate the implantation dose required for splitting a SOI wafer.

关键词： Smart-Cut technology Silicon-on-insulatorwafer Crack growth fracture mechanics Stress intensityfactor

fracture mechanics analysis on Smart-Cut~technology.Part 2:Effect of bonding flaws

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Acta Mechanica Sinica 2009年第2期25卷 197-203页

作者： Bin Gu Hongyuan Liu Yiu-Wing Mai Xi Qiao Feng ShouWen Yu Centre for Advanced Materials Technology (CAMT) School of Aerospace Mechanical and MechatronicEngineering (AMME) J07 University of SydneySydney NSW 2006 Australia Department of Engineering mechanics Tsinghua University Beijing 100084 China

In Part 2 of the paper on the Smart-Cut process, the effects of bonding flaws characterized by the size and internal pressure before and after splitting are studied by using fracture mechanics models. It is found that the bonding flaws with large size are prone to cause severe deviation of defect growth, leading to a non-transferred area of thin layer when splitting. In a practical Smart-Cut process where the internal pressure of bonding flaws is very small, large interfacial defects always promote defect growth in the splitting process. Meanwhile, increasing the internal pressure of the bonding flaws decreases the defect growth and its deviation before splitting. The mechanism of relaxation of stiffener constraint is proposed to clarify the effect of bonding flaws. Moreover, the progress of the splitting process is analyzed when bonding flaws are present. After splitting, those bonding flaws with large size and high internal pressure are vulnerable for the blistering of the thin film during high-temperature annealing.

关键词： Smart-Cut technology fracture mechanics Stress intensity factor Interfacial defect

fracture mechanics and Its Application in the Fatigue Behavior of Reinforced Welded Hand-Holes in Aluminum Light Poles

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Open Journal of Civil Engineering 2023年第4期13卷 677-694页

作者： Cameron R. Rusnak Craig C. Menzemer Earthquake Engineering Laboratory Department of Civil and Environmental Engineering University of Nevada Reno Nevada USA Auburn Science and Engineering Center Department of Civil Engineering The University of Akron Akron Ohio USA

Predicting fatigue life of a given specimen using analytical methods can sometimes be challenging. An approach worth considering for this prediction involves employing fracture mechanics. fracture mechanics can complement both laboratory experiments and finite element analysis (FEA) in estimating fatigue life of a given specimen, if relevant. In the case of aluminum light poles containing a welded hand-hole, the fatigue life has not yet been thoroughly predicted. The University of Akron has conducted a comprehensive fatigue study on aluminum light poles through various means, albeit without of predicting of said fatigue life of the specimens. AFGROW (Air Force Growth) can be used as a fracture mechanics software to predict fatigue life. ABAQUS was used (for FEA) in conjunction with the AFGROW analysis. The purpose of this study was to ultimately predict the life of the specimens tested in the lab and was achieved with various models including hollow tube and plate models. The plate model process was ultimately found to be the best method for this prediction, yielding results that mimicked the data from the laboratory. Further application for this form of fracture mechanics analysis is still yet to be determined, but for the sake of aluminum light poles, it is possible to predict the fatigue life and utilize said prediction in the field.

关键词： fracture mechanics Finite Element Analysis AFGROW Fatigue Analysis Structural Analysis

General solutions of plane problem in one-dimensional quasicrystal piezoelectric materials and its application on fracture mechanics

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Applied Mathematics and mechanics(English Edition) 2015年第6期36卷 793-814页

作者： Jing YU Junhong GUO Ernian PAN Yongming XING School of Science Inner Mongolia University of Technology College of General Education Inner Mongolia Normal University Department of Civil Engineering University of Akron

Based on the fundamental equations of piezoelasticity of quasicrystals （QCs）, with the symmetry operations of point groups, the plane piezoelasticity theory of one- dimensional （1D） QCs with all point groups is investigated systematically. The gov- erning equations of the piezoelasticity problem for 1D QCs including monoclinic QCs, orthorhombic QCs, tetragonal QCs, and hexagonal QCs are deduced rigorously. The general solutions of the piezoelasticity problem for these QCs are derived by the opera- tor method and the complex variable function method. As an application, an antiplane crack problem is further considered by the semi-inverse method, and the closed-form so- lutions of the phonon, phason, and electric fields near the crack tip are obtained. The path-independent integral derived from the conservation integral equals the energy release rate.

关键词： quasicrystals （QCs） piezoelasticity fracture mechanics crack complexvariable method

ENRICHED GOAL-ORIENTED ERROR ESTIMATION APPLIED TO fracture mechanics PROBLEMS SOLVED BY XFEM

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Acta Mechanica Solida Sinica 2012年第4期25卷 393-403页

作者： Zhijia Lin Zhuo Zhuang Xiaochuan You Heng Wang Dandan Xu Applied mechanics Lab. School of AerospaceTsinghua UniversityBeijing 100084China

Based on the concept of constitutive relation error along with the residual of both origin and dual problems, a goal-oriented error estimation method with extended degrees of freedom is developed in this paper. It leads to high quality local error bounds in the problem of fracture mechanics simulation with extended finite element method （XFEM）, which involves enrichment to solve a stress singularity in the crack. Since goal-oriented error estimation with enriched degrees of freedom gives us a chance to evaluate the XFEM simulation, the stress intensity factor calculated by two kinds of XFEM programs developed by ourselves and by commercial code ABAQUS are compared in this work. By comparing the reliability of the stress intensity factor calculation, the accuracy of two programs in different cases is evaluated and the source of error is discussed. A 2-dimensional XFEM example is given to illustrate the computational procedure.

关键词： goal-oriented error estimation extended finite element method fracture mechanics error bounds

Life Prediction of Ball Grid Array Soldered Joints under Thermal Cycling Loading by fracture mechanics Method

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Journal of Materials Science & Technology 2001年第1期17卷 165-166页

作者： Hongyuan FANG Li WANG Yiyu QIAN National Key Laboratory of Advanced Welding Production Technology Harbin Institute of TechnologyHarbin 150001China

Fatigue crack propagation life of ball grid array (BGA) soldered joints during thermal cycling loading was investigated by fracture mechanics approach using finite element analysis. The relationships between the strain energy release rate (G) and crack size (a), thermal cycle numbers (N) can be derived.’ Based on the relationships, fatigue life of the soldered joints was determined. The results showed that crack propagation life was higher than crack initiation life. Therefore, it appears that it is more appropriate to predict the fatigue life of soldered joints using the fracture mechanics method.

关键词： fracture mechanics Thermal Cycling Soldered Joints soldered joints fracture mechanics crack propagation strain energy release rate fatigue life finite element analysis crack initiation thermal cycling ball grid array

fracture　mechanics　ANALYSIS　OF　THERMAL　STRAINFATIGUE　LIFE　FOR　THE　SINTERING　MACHINE　PALLET

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Acta Metallurgica Sinica(English Letters) 1996年第3期9卷 223-226页

作者： LI Zhenzi and LI Ming (Department of Architectnre Engineering, Central South University of Technology, Changsha 410083, China)LIAO Fuchang (Shenzhen School of Technology, Shenzhen 518029, China)

In recent years elastic-plastic fracture mechanics has developed rapidly and is widely used to solve various engineering problems. The application of elastic-plastic fracture mechanics on the pallet of sintering machine is approached in detail for the first time in the present study. The theoretical results were compared with the actual data determined from sintering machine pallet. Results show that good agreement was achieved between the method suggested by the author and the actual data. The basis of determining design of the sintering machine pallet in iron and steel engineering has been provided and it will result in great economic benefits.

关键词： pallet thermal strain fatigue life fracture mechanics

fracture mechanics analysis in frost breakage of reservoir revetment on cold regions

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Research in Cold and Arid Regions 2011年第4期3卷 319-324页

作者： XiaoZhou Liu Peng Liu Key Laboratory for Prediction ＆ Control on Complicated Structure System of the Education Department of Liaoning Province Dalian University Dalian Liaoning 116622 China State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental Engineering Research Institute Chinese Academy of Sciences Lanzhou Gansu 730000 China

Reservoir revetment in cold regions is often damaged by frost due to the joint action of low-temperatures and cryogenic environment in winter. This damage reduces or even eliminates the function ofthe reservoir revelrnent. In this paper, practical problems in engineering were analyzed for the drainage pumping station of Tuanjie Reservoir. Based on a tradifional method of analysis and calculalion, fiacture mechanics was iricorporated to provide quantitative analysis and calculation on the problem of anti-freeze damage from the viewpoint of fracture mechanics. Thus, a new idea is put forward to resolve anti-freefing ofreservoir slope proteclion in cold regions.

关键词： slope protection fracture mechanics low temperature ice stress

EXPERIMENTAL METHOD OF DYNAMIC CAUSTICS AND ITS APPLICATION IN fracture mechanics

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Acta Mechanica Sinica 1987年第2期3卷 160-172页

作者： Su Xianji Lei Zhihui (Dept.of Mech.,Peking University) Dept. of Mech. Peking University Beijing China

The equation of static and dynamic caustics,and the formulae determining the positionof crack tip and stress intensity factor are given.It is proven that for the case of low speed of crackpropagation the static formula is applicable in calculation.A simple method to measure the staticstress-optical constants is proposed.An Optical system which is suitable for the experiments ofdynamic caustics was set-up and used to study the fracture in beam and rings with initial crack underimpact loading.A series of dynamic caustics’ photographs and curves showing the variations ofcorresponding crack lengths and dynamic stress intensity factors with time,are presented.

关键词： dynamic caustic method fracture mechanics