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santosh maharana

Error while creating .fem in optistruct and .h3d body for motionsolve/view in OptiStruct

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hello

i m trying to make h3d from .fem. i m doing as it is tutorial in MotionView/MotionSolve which are available @  http://www.altairuniversity.com/learning-library and search for motorcycle.

 

i created my own motor cycle frame in optistruct then i meshed it and created rigid components. 

like

image.png.077e4eace25e76f13c5545b9b2d8d230.png

 

then i followed the  Generating a Flexible Body for use in Altair MotionSolve - RD-4030

https://www.sharcnet.ca/Software/Hyperworks/help/hwsolvers/hwsolvers.htm?rd4030.htm

 

then i did optistruct and created .fem file

while importing that file

image.png.bc7f7bda37515bd7ed0126ade5d455aa.png

 

error message came:

 

  
 *** OptiStruct defaults set from:
   install config file: C:\Program Files\Altair\13.0\/hwsolvers/optistruct.cfg.
  

 NOTE # 9199
 MSGLMT=STRICT is active, all messages will be printed.
 You can suppress some less important warning messages by use of
  MSGLMT=BRIEF or UNREF (in config file or in the input data).

 2 PARAM(s) were set:
    COUPMASS,-1
    CHECKEL ,YES
  
  

 *** INFORMATION # 741
 No need to constrain the rotational d.o.f. of this dependent grid.
    RBE2 element id = 1309054
 independent grid id = 237100
   dependent grid id = 5
 This is because there isn't any stiffness and load on the rotational
 d.o.f. of the dependent grid.

 *** INFORMATION # 741
 No need to constrain the rotational d.o.f. of this dependent grid.
    RBE2 element id = 1309054
 independent grid id = 237100
   dependent grid id = 6
 This is because there isn't any stiffness and load on the rotational
 d.o.f. of the dependent grid.

 *** INFORMATION # 741
 No need to constrain the rotational d.o.f. of this dependent grid.
    RBE2 element id = 1309054
 independent grid id = 237100
   dependent grid id = 7
 This is because there isn't any stiffness and load on the rotational
 d.o.f. of the dependent grid.

 *** INFORMATION # 742
 The dependent rotational d.o.f. of this rigid element is removed.
     RBE2 element id =  1309055
 independent grid id =   237106
 a dependent grid id =    83333
 This is because there is no need to constrain the rotational d.o.f. of
 any of the dependent grids.

 *** INFORMATION # 742
 The dependent rotational d.o.f. of this rigid element is removed.
     RBE2 element id =  1309056
 independent grid id =   237103
 a dependent grid id =    14115

 *** INFORMATION # 743
 The total number of grids whose rotational d.o.f.s need not be
 constrained in RBE2 elements is 1468.

 *** INFORMATION # 743
 The total number of rigid elements, whose rotational dependent d.o.f.
 are removed because there is no need to constrain those d.o.f., is 2.

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 1 
      component = 1 
     SPC set id = 0

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 1 
      component = 2 
     SPC set id = 0

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 1 
      component = 3 
     SPC set id = 0

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 1 
      component = 4 
     SPC set id = 0

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 1 
      component = 5 
     SPC set id = 0

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 1 
      component = 6 
     SPC set id = 0

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 2 
      component = 1 
     SPC set id = 0

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 2 
      component = 2 
     SPC set id = 0

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 2 
      component = 3 
     SPC set id = 0

 *** ERROR # 176 ***
 A dependent d.o.f. of rigid elements is constrained in an SPC set.
        grid id = 2 
      component = 4 
     SPC set id = 0

 *** More of ERROR messages # 176 were suppressed...

 

then

.h3d not created

 

please help me  

my objective is do optimization of my motorcycle frame  

and to apply loading condition i want to use motion solve to extract loads 

then do topology optimization to get new optimized design.

exactly same as 

 

MC.PNG

 

my problem is i m not able to create h3d file 

i want to know what load steps i use to create successful result

 

 

regards

santosh 

 

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Hi Santosh Maharana,

 

The rigid elements used for Interface nodes of flexbody should be RBE2 type (not RBODY). 1D>rigids> to create rigid spiders set nodes multiple nodes for dependent, and calculate node for independent. Also, make sure to set the elem types to RBE2.

This tutorial might help you: MV-2010: Flexbody Generation using Flex Prep and Optistruct

 

ERROR # 176 is because SPC constraints were applied on dependant nodes of rigid elements, which is not allowed. 

My guess for INFORMATION # 741 is because the rotational d.o.f. were constrained on solid elements, which do not have rotational DOF. INFORMATION # 742 & 743 explain this is unnecessary and they were automatically corrected.

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18 minutes ago, santosh maharana said:

image.png.9f8b916aeff76bc003d1d042d1927963.pngwhat card i have to put and what load collector will i use to follow the above process.

image.png.65c4c2d7deed67a214dae903305fa015.png i corrected to RBE2. 

can you tell me what load collector and card i have to input to follow the above tutorials.

can you tell me the steps. @Ivan

Hi,

 

Do you want to convert to flex body for MBD analysis?

 

Did you follow the tutorial?

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For creating a flexbody you need material and property details. 

 

You can also refer to this MV-2021: Simulating an Automotive Door Closure Event

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@santosh maharana

 

If you want to create a flex body for MBD analysis which can be used by MotionSolve, please export the deck without any loadsteps and use FLEXPREP tool in MotionView.

 

Just retain Mesh, properties and material. No loads or BCs

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i know that one but i m need to do further optimization after analysis that why i imported my file to hyper mesh then mesh is generated and RBE2 created where i will join suspension in hyper view from where i get load .Mnf file then again i use this for optimization in Optistruct.

my objective

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@santosh maharana

 

If at all you are interested in load extraction, you can do that with a rigid body as well

 

If you want to study the deformation, you need a flexible body. Interface nodes are those where flexible body connects to the rest of the model.

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As suggested, 

 

Please don't have any loads or BCs for creating a flexible body. The Dofs of RBE2 has nothing to do with the SPCs and loads. 

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I m not able to get interface node automatically like explained in image.png.aeb884f232f388915749aff134887e03.png example

image.png.a6fa6a386d67b08738245f6aa0c318df.pngafter creating RBE2  spider

my computer won't able perform after 

image.png.f28b11d8497c4a8d99b8171fa76655c4.png

step3 save and exit

 

if i try manually input my interface nodes by tool>> find >> nodes >> number

image.png.d2b5577ce6456346eee4f6f840e722f3.png

 

image.png.7e495883ac29245fd2348fc4e73519a6.png

on clicking ok 

facing error on flex-preparation  

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As per our talk i m sending you my design space file of motor cycle.
i won't able to create  input my interface nodes while creating flex preparation
same thing i am trying in solidthinking inspire in motion, wont able get FEA analysis.

 

https://drive.google.com/file/d/1dN7enQkP2hVbMmvJynrDCX7VJBmhmVBT/view?usp=sharing

 

https://drive.google.com/file/d/0Bx_nUMIj4agbUmhyTUhvVGhYVFN2Z1h3TDlKNGhkbW5uY2c0/view?usp=sharing

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Hi @santosh maharana

 

As said, please delete the SPCs and also the mesh quality is also bad. Please refine the mesh and try again. 

 

I remeshed the model with element size of 10 and I am able to create a flexbody without any errors. But with the element size of 10, there are few areas which are not captured completely. 

 

You may have to mesh carefully.

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