iMechanica - EM 388F - Comments

Traction-separation law

Sergej Tarasov — Sun, 27 Jul 2008 08:07:22 -0400

From my experience, the shape of traction-separation curve has little effect on the load-displacement curve for linear materials. The initial stiffness of the cohesive elements should affect the slope of the first part of load-displacement curve, and the "sharpness" of the peak load value depends on the strength (maximal traction) of the elements. As the crack propagates all curves should practically coincide, as we see in Case 3. But results for Case 1 look quite strange.

Excellent work

yanyabin — Sat, 26 Jul 2008 10:00:23 -0400

You have done an excellent work!

Here what I want to say is that I am also working on using cohesive elements to simulate the delamination process in pizeoelectric thin films. Layers in this kind of thin films are in micrometer or even nanometer scale. What's more, my simulation is also based on a sandwiched-cantilever experiment.

In my simulation, some different kinds of cohesive zone models are used and their traction-separation laws are programmed in the user subroutine in ABAQUS. By reading your paper attached in your blog, I know that the bilinear cohesive zone model was used in your simulation. So, did you applly other kinds of cohesive zone models in your simulation? Did you code their constitutive relations in the user subroutine?

Therefore, I am very interested in communicating with you about the cohesive zone models. Do you have spare time to have this kind of communication with me?

PS: My e-mail: yanyabin@gmail.com.

regards

yanyabin

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

note

Huai Huang — Sun, 11 May 2008 08:21:26 -0400

changed some incorrect notes in ppt, maybe need more polish

term paper uploaded

Masayuki Wakamatsu — Fri, 09 May 2008 14:42:43 -0400

imechanicians & Dr. Huang,

Please find the attached EM 388F term paper.

If anyone is struggling to have cohesive element to work, please feel free to contact me.

I couldn't have made numerical analysis without generous support from fellow phd. student.

regards,

masa

Good work

Rui Huang — Fri, 09 May 2008 14:10:26 -0400

It is interesting to see how the shape of traction-separation curve affects the load-displacement response as well as the crack growth behavior.

Thanks!

Chen Shi — Mon, 05 May 2008 21:56:35 -0400

Thanks!

Presentation File Updated

Masayuki Wakamatsu — Wed, 30 Apr 2008 18:38:05 -0400

imechanicians,

Please find the attached presentation file.

masa

Term Paper Presentations on Wednesday, April 30, 2008

Rui Huang — Mon, 28 Apr 2008 18:42:34 -0400

1. The effect of free surface on stress intensity factor in 3D crack problem

2. Subcritical Cracking of Low-k Dielectrics

3. Low-Cycle Fatigue Behavior of a Lead-Free Solder

4. Fracture of Orthotropic Materials under Mixed Mode Loading

5. Numerical Method in Fracture Mechanics

6. Crack growth in linear viscoelastic media

7. Theory and analysis of a DCB specimen for determining the toughness of PC-3 Prostate Cancer

Term Paper Presentations on Monday, April 28, 2008

Rui Huang — Mon, 28 Apr 2008 15:58:26 -0400

1. Fracture Mechanics of Delamination Buckling and Growth in Laminated Composites

2. Fatigue analysis of Deepwater Risers

3. Channel Cracking in Low-k Interconnect Structures

4. Discussion of fracture criterions with the crack surface boundary conditions of piezoelectric materials

5. Application of Fracture Mechanics on Cortical Bone Studies

6. Interface Fracture – Analysis and Numerical Assessment of SAM-SAM Fracture with ABAQUS

7. Nanoindentation in experimental fracure mechanics

your title and tags

Rui Huang — Mon, 07 Apr 2008 22:29:39 -0400

Rong,

Please add "EM 388F" to the beginning of your title and correct your tags separated by semicolons.

your title

Rui Huang — Mon, 07 Apr 2008 22:27:28 -0400

Suk-kyu,

Please add "EM 388F Term Paper:" at the beginning of your title.

shorten your title

Rui Huang — Mon, 07 Apr 2008 22:24:01 -0400

Justin,

Please shorten your title so that it can be properly displayed.

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.