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

santosh maharana_21480

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

 

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

 

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 

 

 

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 

 

Simon Križnik

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.