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ABAQUS_UMAT_STATEV

Submitted by Marina Trajkovic on Mon, 04/13/2009 - 11:33

Dear all,

do you know does any entry stored is STATEV, used in UMAT subroutine,
should remain unchanged for the next increment for the case of finite
deformation?

I know that STRESS and STRAN will be rotated by ABAQUS but what about the STATEV?

I want to protect STATEV from any rotation by ABAQUS in order to rotate
it in UMAT by my rotation matrix but I am experiencing that it is
different value at the beginning of new increment in comparison the one
as output from previous increment.

Thanks in advance,

Marina.

2009 Gordon Research Conference on Adhesion

Submitted by Anonymous (not verified) on Mon, 04/13/2009 - 00:30

conference

adhesion

Location: Colby-Sawyer College, New London, NH, United States

Sunday, July 26, 2009 - Friday, July 31, 2009

Chair: Jeffrey T Koberstein (Columbia University)

Vice Chair: Chung-Yuen Hui (Cornell University)

Web Site: http://www.grc.org/programs.aspx?year=2009&program=adhesion

Online Application: http://www.grc.org/application.aspx?id=13784

Learning temperature, pressure, and chemical potential

Submitted by Zhigang Suo on Sun, 04/12/2009 - 13:48

education

thermodynamics

I have updated sections of my notes on thermodynamics. A few thoughts on learning are collected here. Of our world the following facts are known:

Hertz contact question

Submitted by Mikael Öhman on Sat, 04/11/2009 - 14:58

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Hertz contact

Dear all

I'm doing an analysis where i need to evaluate the contact area acoording to hertz theory.

I have a book which shows me every step, except for how to calculate two coefficients, and insteads gives me a table of calculated values.

For the contact patch dimensions a and b, i get the expression

where i need to determine m and n. My book (A swedish book without ISBN) simply states that m and n are functions of theta,

and writes a large table with m and n for different angles

Lecturer Positions in Mechanics/Materials at Univ of Mich-Shanghai Jiao Tong Univ Joint Institute

Submitted by Robert G. Parker on Sat, 04/11/2009 - 10:40

Lecturers - University of Michigan-Shanghai Jiao Tong University Joint Institute

Optimal structural design against elastic instability

Submitted by Jim Barber on Fri, 04/10/2009 - 18:15

research

In the classical Euler buckling problem, the critical buckling load can be increased by a factor of four if the first mode is suppressed by placing an additional simple support at the mid-point.

The issue of the computation of the deformation gradient in Abaqus

Submitted by Malik Ait-Bachir on Fri, 04/10/2009 - 09:42

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Abaqus deformation gradient polar decomposition

Hi everybody,

I am trying to model an anisotropic hyperelastic material in plane stress under uniaxial tension

where W=Wiso +Wani= C₁₀*(I₁-3)+C₄*(I₄-1)² .

When the load is parallel or perpendicular to the fiber direction, the deformation gradient returned by Abaqus matches the theoretical expression obtained after derivation of W.

However, when the fiber direction is neither parallel nor perpendicular to the load, the deformation gradient returned by Abaqus differs

modelling of axisymmetric cold extrusion die by abaqus

Submitted by Anonymous (not verified) on Fri, 04/10/2009 - 09:08

research

my problem is simulation of axisymmetric cold extrusion die. the die is conical, i have to determine die pressure, ram force and temprature in billet as well in die, plz see attached file and see simulation figure, my problem is same as in file,i have facing interaction problem in abaqus while solving this problem. plz help me