ES 242r

I was working on the problem set for and on question 16 and 17 refers to a paper by Charalmbides, Lund, Evans and McMeeking entitled 

"A Test Specimen for Determining the Fracture Resistance of Bimaterial Interfaces." (1989)

This set of homework is on mixed mode fracture and interfacial fracture

Buckling delamination, with two slides on 1D vonKarman plates.

• Z. Suo and J. W. Hutchinson, "Interface crack between two elastic layers," Int. J. Fracture, 43, 1-18 (1990).
• Section III in J.W.
  

• Williams singularity
• Energy release rate
• Mode angle
• Stress oscillation
• Small scale contact
• Example 1:  A small crack on the interface
• Example 2:  Thin film debonding
• Interfacial fracture energy
• Four-point bend specimen
• Double-cantilever beam
• The use of the interfacial fracture energy
  

Problem Set 2

I am working on my PhD in Biomedical Engineering at the University of Neb. and have enrolled inES 242r because failure modes of many orthopedic implants can be attributed to initial flaws & fractures of material coatings.  This course, albeit, focuses on ductile materials, the principles seem relevant.

Dear Students of ES 242r / ENGM 940:

You may be interested in reading about the self-introductions of your fellow students. 

The attached notes are written mainly for myself. Most figures are missing. I'll draw these figures in class. So please take good notes in class.

I am pretty new to having a class that is fully powerpoint presentations and am wondering how everyone else is coping with it. Does anyone have any pointers or useful ways they keep notes in powerpoint classes? Printing the notes before hand? Anotating directly on the notes? Having a seperate notebook for notes and seperate handouts of presentation, etc etc?

I am a PhD student at the University of Nebraska Lincoln. I obtained MS in Engineering Mechanics from the University of Nebraska Lincoln, where my thesis was focused on numerical simulation of elastic wave propagation in polycrystalline material, and Bachelor of Engineering in Mechanical from Pune University, India. At present I am working with Dr. Joseph A. Turner in the Ultrasonics and Vibration group. My research is primarily focused on the ultrasonic wave propagation in heterogeneous media using statistical approaches. My research has both theoretical/numerical and experimental aspects for materials characterization and nondestructive testing purposes.

Hi my name is Karla Polivka. I am working part-time on my PhD degree in Mechanical Engineering at the University of Nebraska-Lincoln (UNL). What I mean by part-time is that I have been taking one class a semester for the last 5 semesters. I also received my Bachelors and Masters degrees in Mechanical Engineering from UNL.

I'm Xuanhe Zhao, a first year PhD student working in Suo's Group, at Harvard University. Prior to coming to Harvard, I obtained a Master Degree in Materials Engineering from University of British Columbia.

My name is J. Alberto Ortega, and I am a PhD student in civil engineering at the Massachusetts Institute of Technology (MIT). My undergraduate education took place in Texas A&M University (I am a proud member of the Fightin’ Texas Aggie Class of 2002, WHOOP!), majoring in Structural Engineering. I recently obtained my Master of Science degree in Structures and Materials from MIT.

    I am Ashwani Kumar Goel, currently pursuing my Ph.D. from Engineering Mechanics Department, University of Nebraska Lincoln. I am from India. I have taken my Bachelors degree in Mechanical Engineering from HBTI, Kanpur,India and my Masters degree in Applied Mechanics from IIT, Delhi, India. I have taken lots of courses related to solid mechanics starting from my undergraduation. I have taken strength of materials ,applied mechanics, mechanics of solids during my undergraduate degree and applied elasticity, theory of plasticity, theory of plates and shells, continuum mechanics, linear viscoelasticity during my graduate degree. The group I work in focuses on theoretical, computational and experimental methods for the modeling and analysis of materials and the simulation of their response. I have been part of this group for about two and half years and focusing on theoretical and computational methods to extract material characteristics from novel experimental methods and in the implementation of these characteristics into simulations.

My name is Adrian Podpirka and I am a first year graduate student at Harvard studying Applied Physics. My undergraduate major was material science and engineering at Columbia University. Before taking fracture mechanics this semester I have taken Solid Mechanis (ES 240) with professor Suo.

Hi all,My name is Emmeline Lemos, I am a current Master student in Civil Engineering at University of Nebraska-Lincoln. I took my bachelor degree in Civil Engineering at my home country-Brazil. When I decided to leave my country and to come to graduate school,  I came with the great desire to learn more, and to try to absorb as much as possible from teachers, classmates and this new world that I'm surround by. Definitely, this desire to learn is one of my strengths and makes me overcome the challenges.  

As can be seen from my previous and current degree, most of my background is in Civil Engineering which give me not so much knowledge in Mechanics and been one of my weakness. But, Fracture Mechanics is not the first class that I’m taking in this field; I already took FEM and Continuum Mechanics.

My name is Jeff Chambers, I am a 1st year PhD candidate in the Department Aeronautics and Astronautics at MIT. I received my BS in Mechanical Engineering from the University of California, Santa Barbara. While at UCSB, I worked with Prof. Keith Kedward investigating impact of composites. I did my MS in Aero/Astro at MIT working with Prof. Brian Wardle on durability of structural health monitoring systems. My PhD project is investigating failure theories for traditional composites. I will be working with Prof. Paul Lagace. My research lab is the Technology Laboratory for Advanced Materials and Structures (TELAMS).

Lecture 7.  Stability of large scale yielding crack growth & fracture mechanisms

I am Nitin Sharma, enrolled as M.S. student in Mechanical Engg. at UNL. I did my B.Tech in Mechanical Engg. in India. Worked as an Application Engineer in CAE, for some years, before deciding to take sabbatical and head back to school. Other courses that I have taken in solid mechanics include Mechanics of Materials and Mechanics of Composite Materials (currently enrolled). I feel that my experience with Finite Element codes would help me simulate crack propogation numerically. However, coming back to school after a long time makes me little out of touch with some mathematical concepts.

My name is Ling Zhu and I am currently a PhD student in Mechanical Engineering of University of Nebraska Lincoln. I got my bachelor degree in Civil Engineering from Nanjing University of Science and Technology, China and master degree in Engineering Mechanics from Zhejiang University, China. The research group I am now in is called Midwest Roadside Safety Facility ( mwrsf.unl.edu ) and I am doing the research of simulation of material failure. We are using nonlinear FE software LS-DYNA to simulate the design before performing real-life physical test to reduce the cost.

Point by point, here's the goods:

• I am currently enrolled at the University of Nebraska-Lincoln.
• Prior mechanics courses include: Mechanics of Materials, Advanced Mechanics of Materials, and I'm currently taking Mechanics of Composite Materials
• I received my Undergraduate degree in Civil Engineering from the University of Nebraska Lincoln.
• My strengths for this class...
  

My name is Jamilla Lutif. I am up to finish my Master in the Civil Engineering Department at UNL. My BS degree is also in Civil Engineering, and I got the BS degree at the Universidade federal do Ceara, in Brazil.

Dear all:

Please post your self-introduction online, following the instruction, but turn in the rest of your homework on paper to your teaching assistants.

Students from Harvard and MIT turn in homework to
Zhen Zhang, (617)-384-7894, zhangz@deas.harvard.edu, Pierce Hall 406, Skype: flyinskypku.

My name is Nanshu Lu. I am a second year doctoral student in the Suo group at Harvard Engineering and Applied Science.

I obtained my B.S. in Solid Mechanics from the Department of Engineering Mechanics at Tsinghua University, China. You can see my resume here.

My course background includes Strength of Materials, Continuum Mechanics and Fundamental Elasticity taken at Tsinghua University and graduate level Elastisity (ES 240) taught by Prof. J. Rice, Deformation of Solids (APY 293) taught by Prof. F. Spaepen, Fracture (ES 247) and Plasticity (ES 246) taught by Prof. J. Vlassak and Zhigang's another course Advanced Elasticity (ES 241) this semester here at Harvard.

My first teaching experience was TFing Zhigang's ES 240 last semester.

Although I think I've indulged in a systematic cognition of solid mechanics with somewhat solid understanding of this subject, I sometimes do lack a spirit of digesting materials and making them my own. It indeed has occured to me that having a hard time to fish out the proper solution to a novel problem although I've owned all the needed tools and skills. Under the instruction of John and Zhigang I hope I will make the transformation from a student learner to a scholar learner.

Nonlinear fracture mechanics joints main parts of solid mechanics: fracture, elasticity and plasticity, the essential foundation to my research interests of mechanics in thin films, both theories and experiments. One of my subject is about chip packaging interaction. It is well known that nowadays a typical electronic package assembly consists of different materials which are attached together in a variety of ways. No other course will be more proper for this subject than this "Fracture mechanics of thin films and composit materials". Though I've read literatures specialized on thin film debonding I believe taking this course is the most efficient way for me to have profound and comprehensive understanding of fracture mechanics as a whole.