Blog posts
How to explain the limit load by stiffness matrix using finite element analysis?
I always have a question about the convergence problem: when a structure reaches its maximum load-bearing ability, the solution will end if the newton method is used in the finite element analysis. Then which form the stiffness stiffness in the finite element analysis takes on? Singular or ill-conditioning? How to explain the appearance of maximum load by variable stiffness matrix?
Multiscale Modeling and Simulation
There is an academeic group on Facebook called "Multiscale Modeling and Simulation"( http://www.facebook.com/home.php?#/group.php?gid=51889855338). The provided information is very helpful.
Young's modulus
Hi all,
I have this confusing thought for a quite long time.
Is there any relation between the time-independent Young's modulus with the time-dependent Young's modulus (instantaneous and equilibrium moduli or loss and storage moduli)?
If yes, what is the equation to relate them?
So many terminologies which make this confusion!
Please help.
Wanbot
UMAT subroutine in ABAQUS for elasto-plastic cyclic loadings
I want to implement the elasto-plastic model for cyclic loadings (I suppose
something like chaboche) into the UMAT subroutine in my ABAQUS model ,
but I haven't enough knowldge for do this. I read some book like mechanichs of solid materials but i don't understand how to implement my constitutive law into the subroutine. until the load is static i don't have many problems, but when i work with cyclic load I'm non able to generate a cyclic increments of plastic behaviou.
Modelling Hyper-elastic Plate Using ABAQUS
Dear All,
For months, I have tried to model a plate with circular hole which has the properties of hyper-elastic material (Ogden) but the results are still not promising compared to literature (Y Basar 1998). The main problems are:
1. The maximum load I succeeded to apply was q=26, while literature had applied load up to 90. For q > 26, the analysis will terminate with errors such as too many attempt, excessive distortion etc.
2. The results I get for q<26 are not the same as literature.
I attach my best result for your viewing.
Abaqus: equally space amplitude
Hi,
I've been trying to apply a displacement to a body in an implicit model using equally spaced amplitudes.
Abaqus implicit, rigid body-deformable body contact, negative dot product
Hello,
I am running a simulation where I have a rigid body (shell elements) pushing into a deformable part. Unfortunately, the simulation aborts with the following error:
The dot product -0.19758 cannot be negative for element 30050 instance xzy with record ID 844 at step 2 inc 1 kitgen 5.
This element (C3D4H) belongs to the deformable part and is within the body, so no not close to the contact at all. At the point where the simulation aborts, this element is not deformed and the stress is basically 0 (E-6).