What is stress? Who has ever seen stress? Is stress a physical quantity?
Professor Yi-Heng Chen, Xi’an Jiaotong University, 710049, P.R.China
e-mail: yhchen2 [at] mail.xjtu.edu.cn (yhchen2[at]mail[dot]xjtu[dot]edu[dot]cn)
In fact, this question has been bothering the present author for more than 15 years.
As a consultant in computational mechanics, I currently help write some FEM-related code, and while doing this job, an episode from a recent past came to my mind. Let me go right on to the technical issue, keeping aside the (not so good) particulars of that episode. (In case you are curious: it happened outside of my current job, during a job interview.)
If you are a design engineer, FE analyst, researcher, or any professional dealing with stress analysis in your work, I seek answers to a couple of questions from you:
Question 1:
Dear All,
I think that many students are looking for some tutorials about writing a UMAT in ABAQUS.
You can find a comprehensive tutorial for elastic problems.
This file contains:
• Motivation
• Steps Required in Writing a UMAT or VUMAT
• UMAT Interface
• Examples
Example 1: UMAT for Isotropic Isothermal Elasticity
Example 2: UMAT for Non-Isothermal Elasticity
Example 3: UMAT for Neo-Hookean Hyperelasticity
If someone knows of books/articles dealing with the meaning of the concept of potential in physics (or concerning the physical bases underlying the energy methods of mechanics) then I would very much appreciate getting to know about these.
0. I was idly thinking about the current H1N1 flue pandemic, and the following things occurred to me. Please note, I know very little about this subject matter. So, please consider descriptions in the following as, at best, tentative.
1. There is a basic difference between how alcohol kills viruses and how salt-water kills bacteria. [Alcohol is used in the hand-cleaners they use in hospitals. Girgling with salt-water is the first line of defense (and an unexpectedly highly effective one) which is well known for millenia.]
hello,
I am doing research on the stresses that are produced when a retainer (a thermoplastic sheet) is placed on the teeth. We've designed the project so that we take an initial scan of the sheet and a final "shifted" scan of the sheet. We'd like to compare, find the strain, and calculate the stress neccessary to produce this strain.
I was hoping to use FEA for this...is it possible? I have access to Abaqus and Ansys, and where can i find the commands that allow me to do this.
Crack tip stress and formation of Plastic/influence zone for composite solid rocket propellants
The necessity to understand the crack behaviour of composite solid rocket propellants as it helps in analysis of service life of rocket motors. Experimental data reveals that a material’s microstructure at the crack tip can have a significant effect on the local damage near the crack tip and crack growth behaviour in particulate composites.
I was browsing the discussion page for Stress in Wikipedia when I came upon this interesting comment:
"
Refutation of Cauchy stress
The theory of stress based on Euler & Cauchy is now refuted. The profound incompatibility of this theory with the rest of physics, especially the theory of potentials and the theory of thermodynamics, has been documented in
