Zhigang Suo's blog

I have updated my notes on "Energe Release Rate.  Fracture Energy".  I will use my twitter account to update my teaching, research, and reading.  You will get an automatic update if you subscribe to my twitter account.

I have updated my notes on the Griffith paper.  I added more description on the experimental determination of surface tension of solids.  Griiffith himself determined the surface tension of glass by an experimental setup.  Udin et al (1949) described a setup based on the same principle.  This setup is now known as the zero creep experiment.

The class started today.  I'll be teaching fracture mechanics this semester.  I'll be mostly using the class notes I wrote in 2010, but will post updated ones. 

In today's class I covered "Trouble with linear elastic theory of strength."  I have just posted updated notes of the lecture.  The new notes begin with the follwoing paragraphs.

Apples and oranges. Each element in a set is a pile containing some number of apples and some number of oranges.  Adding two piles means putting them together, resulting in a pile in the set. Multiplying a pile and a real number r means finding in the set a pile r times the amount.  We model each pile as a vector, and the set as a two-dimensional vector space over the field of real numbers.

Update on 9 April 2016.  At the bottom of this post, I attach a pdf file of my notes on scalar.

Notes on scalars now forms part of my notes on linear algebra.

Linear algebra is significant to many aspects of mechanics.  For some years I have been using the book by Shilov.  But this book may or may not be a good one to recommend to a student, depending on his or her prior experience.  On StackExchange Mathematics, there are several excellent threads discussing textbooks of linear algebra.  A particular recommendation was made for

It might be fun for us to work together to collect phenomena of large elastic deformation.  These phenomena will enliven teaching and motivate research.  As inspiration, here are two albums of fluid motion

Caltech has made the Feynman Lectures on Physics, Vol I, freely accessible online.  The quality of the HTML file is exceptionally high.  Take a look at the preface to learn how this electronic version was produced.

A single strand of polymer is a chain of a large number of monomers.  The monomers are joined by covalent bonds, and two bonded monomers may rotate relative to each other.  At a finite temperature, the polymer rapidly changes from one configuration to another.  When the two ends of the polymer are pulled by a force, the distance between the two ends changes.  The polymer is known as an entropic spring.

These notes may serve as a reminder of tensor algebra.  The notes supplement the course on advanced elasticity.  Several books are listed at the end of the notes.

Update on 17 April.  I am now breaking up the notes on tensors, cleaning them up, and posting them as sections on linear algebra.

In the notes on the general theory of finite deformation, we have left the free energy function unspecified. The notes here describe free energy function commonly used to describe the elasticity of rubber-like materials.  These notes are part of a course on advanced elasticity

These notes are part of a course on advanced elasticity.  The notes recall several phenomena where both elasticity and surface energy are significant, including

• Griffith crack
• Adhesion of flexible structures
• Wafer bonding
• Contraction of a soft elastic sheet 

The notes also contain a formulation of combined surface energy and elasticity of finite deformation.  

This classic paper is attached

Reading PDF files of papers and textbooks on computers has long been difficult for me.  The resolution of the screens has been too low.  The computers have been too heavy for reading in couches and beds. 

Full announcement of the meeting (in both Chinese and English) 

申请条件. 具有海外博士学历(5年以内)或者2013年即将毕业的博士。或者具有国内博士学历，已在海外工作或学习2-4年。在本学科领域取得突出成绩或在领域内发表有高水平学术论文。具备工作经验或博士后研究经验更佳。通过资格审查者，由主办单位邮件通知具体参会事宜.

John Hutchinson has just pointed out to me the website, shellbuckling.com.  The site is devoted to the mechanics of buckled shells, with downloadable photos, slides, papers, and computer codes.  The site also has a section on buckling people.  The site is created by a veteran buckling person, Dr. David Bushnell, formerly of Lockheed Martin.  Check the site out, and enjoy. 

（本招聘广告有效期至2012年12月31日）PDF of this file

为了更好地聚集海外优秀人才、培养国际一流的青年学者、及借此加快建设世界高水平大学的进程，西安交通大学建立了一个新型的、采用美国先进的用人和科研体制管理的研究中心---“国际应用力学中心” International Center for Applied Mechanics (ICAM)。该中心的目标是聚集和培养一流人才，产出一流学术成果，打造国际一流的力学学科。ICAM以独立的tenure-track PI为本，将重点研究国际力学前沿问题及国家重大需求中的关键力学问题，承担国家级的重点和重大项目，并开展高层次国际合作与交流。

Sukumar pointed out a Google service to retrieve your papers.  Here are a few examples:

I have divided the old notes on temperature into three parts:

• Principle of the conservation of energy
• Empirical observations of temperature (this part)
• Energy and fundamental postulate 

Our feeling of hotness comes from everyday experiences. These experiences indicate that many levels of hotness exist, and that all levels of hotness can be mapped to a real variable.