instability

Dear colleagues, 

I am writing to invite your contirbution to the mini-symposium on failure and instability in soft materials and geomaterials co-organized by myself, Joshua White, Pencheng Fu, Nikolaos Bouklas, Wei Wang and Christian Linder for the upcoming ICCM conference at Berkeley. More information can be found in the URL listed below. 

http://www.sci-en-tech.com/ICCM/index.php/iccm2016/2016/schedConf/track…

Because of the increasing need of energy, the plants installed by electricity supply utilities throughout the world are becoming larger and more highly stressed. Thus, the risk of turbogenerator shaft cracking is increasing also. The development and propagation of a crack represents the most common and trivial beginning of integrity losses in engineering structures.

Dear collegues

a quick question:- I am playing with continuum models of Contact (Hertz, Westergaard and so on) and friction laws. However, I prefer for my students to use ANSYS FEM code. In Ansys there is standard Coulomb, rate-dependence but not rate-state (unless one codes some user subroutines). See

https://www.sharcnet.ca/Software/Fluent14/help/ans_ctec/Hlp_ctec_realke…

Hi, my question is on the use of Riks and other Arc length methods when analysing  a system for gross plastic deformation. ASME B&PV code , in its investigation for Gross plastic deformation as a Load at which convergence does not take place. Now, as far as I understand, Newton Raphson method fails at locations of singularity in the stiffness matrix and also at Bifurcation points, it can trace the unstable primary paths. Both these issues can be overcome ( provided the limit point is not too sharp) by Riks and other Arc length methods.

Dear all,

 in commercial FE codes, such as ABAQUS, ANSYS, there is option to get convergence in quasi-static analysis by using artificial damping factor. I tried to dig their documentation about this method, but it is somewhat sparse. Could some body recommend me some literature about this topic so that I can gain a better understanding about it.

I thank you in advance.

Sincerely yours,

Ken