viscoelasticity

dear Imechanica friends here is an apparent paradox: for a sliding flat punch on a viscoelastic halfspace, friction is zero or not?  Certainly there seems to be viscoelastic dissipation, but the pressure is also normal to dispacements, so am I missing something obvious here?

Dear all,

I would like to ask you for advice. I am about to simulate a pull-through test (see attached picture) of a cladding panel made of a material with highly viscoelastic behaviour. I have parameters for Maxwell model (Prony series) obtained from test. I expect large deformation and probably cone failure (or tearing of the cladding panel). Therefore I would like to use Abaqus/Explicit. The problem is that I cannot use *visco step together with Explicit. Is there any way to solve it?

Hello everone

I am recently interested in viscoelastic composite materials with ageing effect. I will be very pleased if someone can advise me how to find a constitutive law with ageing effect. 

sincerely

Dear All, 

We (the NanoBIO Node at Illinois ) have a preliminary release of an online finite element analysis of nanoindentation (indentation) tool using FEAP . 

This preliminary release is limited to linear elastic material, axisymmetric geometry, spherical rigid indenter, and various boundary conditions. 

Hi All,

I am a student working on a project involving the effect of residual stresses in elastic and viscoealstic materials. I have a related question: When an easltic body is heated to a certain temperature (say 400 deg C) and then cooled uniformly to room temperature (20 deg C) with a constant cooling rate "q", does this generate any "un-desirable" (residual) stresses within the elastic body? i.e at a steady state - room temperature, does the final stress state within the body would be non-zero? Else, it would eventually reach a state of zero stresses? How?  

The Nanobrücken 2014
Nanomechanical Testing Workshop will take place March 26-28, 2014 at INM -
Leibniz Institute for New Materials in Saarbrücken, Germany. This will be the
4th edition of the now-annual Nanobrücken workshop series. This year's Keynote Speaker will be Andrew Minor (University of California, Berkeley).

Hello All:

I have written a UMAT code to predict the viscoelastic behaviour within a shape adaptive structure. I have followed similar steps used in Abaqus subroutine manual, I have applied this UMAT to a single quad element and it works as predicted. But when I apply it multiple elements model it breaks down. 

Is there any special command i need to put in UMAT subroutine to account multi element analysis? I will appreciate all related comments, 

Thanks