iMechanica - homework - Comments

Actually the displacement

Yuhang Hu — Tue, 21 Oct 2008 21:16:54 -0400

Actually the displacement condition in the hint is consistent with the traction boundary condition. The displacement condition w=τy/μ is derived from the traction condition if ignoring the exist of the hole.

Boundary conditions in Problem22

Kejie Zhao — Mon, 20 Oct 2008 21:26:51 -0400

I feel a little confused that at infinity, could the displacement boundary condition w=Ty/U and stress boundary condition Tzx=Tzy=T be satisfied simultaneously?

Problem20

Kejie Zhao — Wed, 15 Oct 2008 15:27:11 -0400

A small mistake in Hooke's Law as stress component matrix is missed. Also should the subscript be unform, ie. 123 or xyz

pdf file of homework is attached

Zhigang Suo — Mon, 06 Oct 2008 09:13:13 -0400

John: The pdf file is attched. I'll remeber to do so in future.

OOo

Mike Graham — Sun, 05 Oct 2008 19:15:58 -0400

You might try installing OpeOoffice, a free/open-source office suite. It seems to dislay all the math and such properly for me and could make it easier for you to read Word documents people paste in the future.

http://www.openoffice.org/

pdf file?

John M. Kolinski — Sun, 05 Oct 2008 18:50:27 -0400

Prof. Suo, would you mind posting the .pdf file for the hw assignments? I don't have word on my computer, and google docs doesn't read some of the symbols used in the assigments.

Gauthier Chevallard's self introduction

Gauthier Chevallard — Mon, 12 May 2008 15:59:34 -0400

I am a Masters student in Engineering Mechanics

Student from Ecole Centrale

I am working for Dr Liechti and Dr Ravi Chandar

I have to characterize the non linear viscoelastic behavior of a polymer

Xuefeng Zhang's Self Introduction

zhangxuefeng — Sun, 27 Jan 2008 23:36:41 -0500

Sorry for the late post due to my back injury. My name is Xuefeng Zhang, a graduate student from Materials Science & Engineering working on packaging and interconnect reliability. I got my Bachelor/Master degree from the Department of Civil Engineering at Tianjin University, China. I am now working in Dr. Ho's research group (http://www.mrc.utexas.edu/ho.html, http://imechanica.org/user/224). I have taken Solid Mechanics I & II and learned some knowledge of Mechanics. My research involves the characterization of the thermo-mechanical behavior of various of packages used in semiconductor industry. I also study the the mechanical reliability problems in the package and interconnects caused by crack and interfacial delamination under thermal load. So fracture mechanics is very necessary for my research. It can help me better understand the crack behavior in electronic packages and how it will affect their mechanical reliabilities. I have some basic understandings of fracture mechanics and hope to learn more by taking this course. I believe it will be very helpful to my research.

Kuan Lu's self introduction

Kuan Lu — Wed, 23 Jan 2008 10:08:33 -0500

I am a graduate student in Materials Science & Engineering. I got my Bachelor/Master degree from the Department of Materials Science & Engineering at National Tsing Hua University, Taiwan. My Master thesis was about the nano-oxide layer in Giant Magnetoresistance devices. I am now working in Dr. Ho's research group (http://www.mrc.utexas.edu/ho.html, http://imechanica.org/user/224). My prior relative courses are Solid Mechanics I and Thin Film Mechanics. My current research topic is thermomechanical behavior of 3D packaging in semiconductor devices. The failure modes of 3D packaging will be an interesting study, and I hope I can expand my knowledge in fracture mechanics by taking this course.

Thank you I updated.

Huai Huang — Wed, 23 Jan 2008 00:29:07 -0500

Thank you

I updated.

Naoto Sakakibara's Self Introduction

Naoto Sakakibara — Tue, 22 Jan 2008 01:24:12 -0500

Which department or graduate program are you currently enrolled in?

I'm currently enrolled in Engineering Mechnics program.

• Your prior courses in solid mechanics.

Before this coursrm, I have taken Solids Mechanics, Micromechanics, and so on.

• Your undergraduate major and where you were enrolled.

I was enrolled in Arospace and Mechanical engineering, Mechatronics course in Nagoya University in Japan.

• What might be your strength and weakness related to this course.

I don't know a lot about fracture mechancs, therefore I don't know what is my strength. However I think I'm good at mathematics so probably that would help me in this course.

• Your research group if you already belong to one (please give a link to the web page of your group).

Professor Kyriakides

• Your likely research direction(s).

My research topic is Buckling and collapse of internaly defected pipe with external pressure.

• How do you think fracture mechanics will contribute to your education in general?

At this point, I'm not sure how this topic will help my education. However, I think to learn the fracture mechnics will make me understood more about behavior of the material and I'll have more knowlege about mechanics of the material.

Hello, this is Hualiang

hualiang shi — Mon, 21 Jan 2008 00:56:48 -0500

Hello, this is Hualiang Shi, one PhD candidate from the Physics department of UT.

From 1998 to 2003, I was studying at the Physics Department in the University of Science and Technology of China (USTC). My major was condensed matter physics and my Bachelor thesis was about the growth of p-diamond on the p-GaN by using hot filament chemical vapor deposition (HFCVD).

After I got my Bachelor degree at 2003, I entered the Physics Department at UT. During the semester of Fall, 2004, I was really lucky to get the opportunity to join Dr. Ho's group (http://imechanica.org/user/224, http://www.mrc.utexas.edu/ho.html ). The main objective of my research is to study the properties of low-k dielectrics by using Quantum Chemistry Calculation. It includes two parts. The first part is to study the mechanism of plasma damages to low-k dielectrics by using Quantum Chemsitry calculation such as Gaussian or VASP and by using experimental techniques such as FTIR,SE,XPS,XPS depth profile,XRR,Raman,AFM,Contact angle measurement, C-V/I-V measurement,FIB/SEM,and EELS/TEM. The second part is to study the subcritical crack of low-k dielectrics by using Quantum Chemistry calcultion. Other students in my group can measure the energy release rate by using FPB and I can calculate the bonding energy and reaction activation energy. In this way, we can determine how many water molecules are needed for the subcritical crack. It's very clear that the knowledge of Solid Mechanics is very important for my second objective. So during the Fall 2005, I took Solid Mechanics I given by Dr. Huang. That class was wonderful and I learned a lot from it. In order to further enhance my knowledge of solid mechanics, I take Fracture Mechanics this semester. As a Physics student, my background of Mathematics and Physics are very solid and strong. It might be helpful for my study of Fracture Mechanics. But I do need to know more about Mechanics. In the future, I will benefit from Fracture Mechanics. For example, if I want to work in the field of Packaging or Interconnect such as air-gap or 3D interconnect, Fracture Mechanics will help me a lot.

Justin Babcock's Self Introduction

justin.babcock — Wed, 16 Jan 2008 15:42:58 -0500

I am currently enrolled in the Aerospace Engineering MSc program, though for all intents and purpuses I am in the Engineerimg Mechainics program. I have taken Solids I, Advanced Strength of Materials, Mechanics of Composite Materials, Structural Dynamics, and Applications of finite element methods. My strength in this course is going to be that I have been working on my research project for the past year and it is a fracture mechanics based project. My weakness for the course will probably come about from having already learned some of the material in a ceartain way; ie ceartain names for variables, ceartain symbols, etc. I am a part of the center for mechanics of solids, structures and materials. As stated already, I am working on a project that involves fracture mechanics. To be more specific, I am using a double catalivered beam specimen to determine the toughness of PC-3 canter cells. This course is going to help me in my research by giving me a formal traing in the subject. Up to this point I hve been picking up only the details that I need. I will leave this course with a broader understanding of the subject. As far as this course's contribution to my education in general, I think it will provide me with a better insight into solid mechanics. Fracture is a very important subject from a theoretical point of view, in addition to a more applied point of veiw.

Suk-Kyu' Self-Introduction

Suk-kyu Ryu — Wed, 16 Jan 2008 15:11:42 -0500

Hello. I'm a graduate student at Aerospace Engineering Dept. After obtaining Master degree in Republic of Korea, I had worked for almost 7 years. However, I’m enrolled here in 2006 Fall since I felt the necessity of refreshing me. Until now, I’ve taken Solids I, Continuum Mechanics and I’m currently taking Solids II and Plasticity.

Now I’m working with Dr. Huang and supporting Dr. Ho in Material Science Dept.

http://www.ae.utexas.edu/~ruihuang/RHuangGroup.html

Especially, I’m researching the reliability in advanced interconnects and packaging with Tokyo Electron Inc,. Thus, this fracture class is necessarily required for my research. I hope this class helps me catch the concept of fracture mechanics.

Julian Hallai's Self Introduction

Julian Hallai — Wed, 16 Jan 2008 00:01:04 -0500

I’m enrolled in the Engineering Mechanics Graduate Program.

I’ve taken Solids I, Continuum Mechanics, Plasticity and I’m currently taking Solids II.

My undergraduate major was in Naval Architecture and Ocean Engineering at USP in Brazil, where I also got my Master’s degree. Before I enrolled at UT, I worked for four years at INTEC Engineering and at PETROBRAS .

Although very interested about fracture mechanics, I’ve never taken any course on the subject. I’m very happy I’m finally taking this course.

I’m working with Professor Kyriakides and I’m currently researching Lüder Bands in tubes under bending.

I think fracture mechanics is going to be great for this work with tubes and also as background for my future endeavors in Mechanics.