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  1. pirs

    shell element types

    Yes, this is absolutely true. S4R - nodes have rotational d.o.f. SC8R - nodes have displacement d.o.f. only. However, I don't think this explains the differences I am observing, since my mesh is significantly small (large number of elements) in the areas where deformation is expected to occur.
  2. pirs

    solid part with shell properites

    If I am understanding your issue correctly, I think you should try to use a continuum shell element (SC8R/SC6R). These are shell elements, which are defined similarly to solids/bricks. Give it a try...
  3. pirs

    shell element types

    Hello everyone, I have tried to find some answers to this particular question in the theory manual/user manual, but I haven't been successful. My issue lies with the modelling of a simple cold-formed steel structure, i.e. I used shell finite elements since the thickness is considerably smaller...
  4. pirs

    Initial conditions, type=hardening - defining backstresses

    ...looking for some information regarding the inclusion of hardening in cold-formed steel beams. First of all, I have defined my material as follows: *MATERIAL, NAME=steel_corner *DENSITY 7850e-9 *ELASTIC, TYPE=ISOTROPIC 202870, 0.3 *PLASTIC, HARDENING=KINEMATIC 220, 0 398.73, 0.18637574...
  5. pirs

    explicit analysis + standard subroutines - is it possible in any way?

    ...my explicit approach. I have been looking into this further and I think I have realized I might not really need to use the SIGINI subroutine. I just started doing some easy examples, but I think I might be able to get my model to work by using the *INITIAL CONDITIONS, TYPE=STRESS, SECTION...
  6. pirs

    explicit analysis + standard subroutines - is it possible in any way?

    Hello everyone, I am hoping someone out there might have some insight for me regarding this subject. First of all, I am fully aware that the standard subroutines, such as SIGINI, are restricted in abaqus explicit. However, i figured it might be possible to run an initial stress state using the...
  7. pirs

    ABAQUS Explicit - define rotary inertia for a rigid body reference node

    ...I realize that my question was not too clear. So, let me try again... I have defined a rotary inertia element set (1 ROTARYI element, 1 node) with *ROTARY INERTIA. Now I want to associate this element with a rigid plate reference node, which is a well defined node set in my model. Does...
  8. pirs

    Static General analysis and Dynamic Explicit analysis in ABAQUS

    Hi Sutham, I have used both Static General and Dynamic Explicit to model the same event in ABAQUS. In my particular case, I have decided that using explicit provides a much better approach to the results, since I wanted to model time dependent events, even though the time scale is rather long...
  9. pirs

    ABAQUS Explicit - define rotary inertia for a rigid body reference node

    ...requires the definition of a rotary inertia. My idea is that I need to define a ROTARYI element, which contains my rigid plate reference node. *RIGID BODY, REF NODE=SupportPlate.40, ELSET=SupportPlate.SupportPlateElements *ROTARY INERTIA, ELSET=?? I11, I22, I33, I12, I13, I23 My question...
  10. pirs

    rotary inertia - how to define the elset?

    ...requires the definition of a rotary inertia. My idea is that I need to define a ROTARYI element, which contains my rigid plate reference node. *RIGID BODY, REF NODE=SupportPlate.40, ELSET=SupportPlate.SupportPlateElements *ROTARY INERTIA, ELSET=?? I11, I22, I33, I12, I13, I23 My question...
  11. pirs

    abaqus subroutine SIGINI

    ...analysis in ABAQUS/Explicit, which obviously does not support the SIGINI subroutine. However, considering I want to input an initial stress/strain state, is it possible to run a *static step prior to the explicit dynamic step to run SIGINI? Thanks in advance for any possible input on the...
  12. pirs

    Bilinear Isptropic Hardening ? Please Help.

    Adding to my previous answer, eu is defined as the plastic strain, so you should subtract your yield strain from the ultimate strain. Pirs
  13. pirs

    Bilinear Isptropic Hardening ? Please Help.

    ...branch to your material constitutive relation, which would correspond to hardening. I think the answer is to simply add a second line to the *Plastic command, where you introduce the ultimate strength and strain (which you don't mention in your question, i'll name it eu). Example: *Plastic...
  14. pirs

    ABAQUS/Explicit - Thickness Adjustement??

    I think the following additional information might be relevant: shell finite element model - element S4R. element thickness = 4.72mm smallest element facet ~= 1mm (some very small elements are used to model a rounded corner) could this be the problem ? The fact that the element size is...
  15. pirs

    ABAQUS/Explicit - Thickness Adjustement??

    ...general contact algorithm and this formulation has worked successfully on different cases where only some of the geometric dimensions are changed. ***WARNING: In step 1, some facet thicknesses for general contact were reduced from the parent element or specified values due to a...
  16. pirs

    ABAQUS/Explicit - Excess Kinematic Energy

    Just to add something else to my previous post: Modelling the rigid plates is important since I want to observe the behaviour of the beam's web-flange corner near both rigid plates. If I apply a simple displacement to the top flange and constrain the bottom flange I will most probably have to...
  17. pirs

    ABAQUS/Explicit - Excess Kinematic Energy

    Well, it is indeed a compression analysis. I don't necessary need to model the support and load plates, but to some extent the contact interaction between the load application plate and the support plate with the beam are relevant, thus I decided to include them in the model. I have tried many...
  18. pirs

    ABAQUS/Explicit - Excess Kinematic Energy

    ...15-20% of total energy. This is what I have found to be unacceptable, as you pointed out. For the amplitude function I have defined as follows: *AMPLITUDE, NAME=Ramp 0., 0., 100, 1, Given this, the dynamic step is also 100s long: *DYNAMIC, EXPLICIT , 100 *BULK VISCOSITY 0.06, 1.2 As for...
  19. pirs

    ABAQUS/Explicit - Excess Kinematic Energy

    ...which contacts with two rigid plates: one acting as a support and the other acting as a loading plate through applied displacement. I am using the *contact algorythm to perform a quasi-static analysis. However, when observing the results, several sudden increases on the support reaction...
  20. pirs

    ABAQUS/Explicit v6.9 - contact penalty algorythm

    ...a rigid plate. I want to try and use the penalty constraint enforcement method but the processor seems to give an error when I use the following: *Surface Interaction, name=ContactProperties *Surface Behavior, Penalty=Linear Using Direct, or Penalty=Nonlinear seems to give the exact same...

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