Week 4-1D Element Creation Challenge

Challenge4:- To create 1D element on the given component.

OBJECTIVE:- To create 1D element such as ROD,BAR,BEAM on the given component and apply mass on the given component with given dimension and Degree of freedom(DOF).

img1:create 1D element on the given component.

PROCEDURE:

• Import the STEP file by clicking FILE→IMPORT→GEOMETRY→PARALLEL BRACKET(FILE) and click Import.
• generate the Mid surface on the upper bracket:GEOMETRY→MID-SURFACE and select the upper part ,choose automesh option and click extract.
• Once the mid surface is extract on the upper bracket,name the midsurface on the tree as BRACKET_1 and select any colour for diffrentiate the upper bracket.
• Same thing is done for the lower bracket.

img2:midsuface extraction on the upper bracket

img3:midsurface extraction on the lower bracket

• Once the midsurface extraction is done, delete the solid part,.by clicking this icon and select the solid and click delete entity.And also delete the component in the model view.
• Create component and move the lower bracket midsurface onto the component and name the component as BRACKET_2 delete the previous midsurface file,now we have two separate midsurface file.

img4:deletion of the solid part

• After removal of solid part, give washer for every hole and create material,property for the given component.Give the material as MAT1 and assign the thickness in the property.
• click the each component and insert the property and the material.

img:creating washer around the hole

• mesh the entire component with element size of 5mm with mixed type of element:2D→ Automesh →surf→ return

img:meshing of the entiure component.

• Next step is to create RBE2 and RBE3 elements.
• the diffrence between the RBE2 and RBE3 is that:

RBE2	RBE3
The element have infinite stifness means it never bend and translate	The element can be moved
load distribution will be equal(uniform)	The load can be varied means it will not be uniform.

• The links and dimesion are given to the resperctive hole as per the problem statement.

• a. Rod element:- Translational DOF should be Constrained with RBE2 link

  Cross-Section: BOX- Dimension a= 12 mm

  dimension b=10 mm

  Thickness t= 0.75 mm

• b. Beam element:- All DOF should be constrained with RBE3 link

  Cross-Section: I Section- Dimension a= 8 mm

  Dimension b= 10 mm

  Dimension c= 8.5 mm

  Thickness t1= 0.75 mm

  Thickness t2= .6 mm

  Thickness t3= .6 mm

• c. Bar element:- Constrain only x and y DOFs With RBE3 link

  Cross-section: X section- Dimension DIM1= 5 mm

  Thickness DIM2= 1.2 mm

  Dimension DIM3= 10 mm

  Thickness DIM4= 1.2mm
  
  

• For create rod element go to the HYPERBEAM→STANDARD SECTION→THIN WALLED BOX→CREATE.
• give the dimesnion for the thin walled box as per the given statement.

img:thin walled tube(rod)

• same like, create the remaining model BEAM and BAR,go to the hyperbeam view window click left mouse button and choose create→standard section→hypermesh→standard I section.And give the dimesnion.

img:I-cross section beam element

• for bar go to create→standard section→optistruct→cross.And give the dimesnion.

img:cross bar element

• we have to create the RBE2 element on the first hole(a):1D→Rigid→ and select the nodes and element in where we want to create ROD element.
• we have to create the RBE3 element on the first hole(b):1D→RBE3 → and select the nodes and element in where we want to create BEAM element.
• we have to create the RBE3 element on the first hole(c):1D→RBE3 → and select the nodes and element in where we want to create BAR element.

img:after creating RBE2 and RBE3

• after creating the RBE2 and RBE3 links cfeate the element to connect the two nodes inbetween each hole inorder to create the ROD,BAR,BEAM.
• Go to rod→ node(select the each node on the either side of the bracket)→ element type(CROD) and then click tab button.
• for second hole(b),go to bar→ node(select the each node on the either side of the bracket)→ element type(CBEAM) and then click tab button.
• for third hole(c),go to the bar→ node(select the each node on the either side of the bracket)→ element type(CBAR)and then click tab button.

img:elements are creted by joing two nodes.

• once the element has been created,assign property to each of the element,By right click on the model view,go to create→ property→ and select the card image and select material for each element.

img:property assign to the each element

• Card name for ROD : CROD
• Card name for BEAM: CBEAM
• Card name for BAR : CBAR

img:property for BAR element

img:property for BEAM element

img:property for BAR element

• once the property has been assigned we can see the cross section for each of the element by clicking I-D detailed element representation.

img:after assign the property for the elements.

• we have to create the RBE2 element on the hole(d,e,f) and apply mass of magnitude 10.

img:creating RBE2 element on the hole(d,e,f)

• after creating RBE2 element assign the mass of magnitude 10 on the node of each element:geometry→masses→create→enter the mass→select thre property→element type→create.

img:adding mass on the each node

• create spring element in between RBE2 link on the either side of the bracket.go to 1D→springs→select the node on the each (parallel side) on the bracket→property→element type and click tab button.

img:spring created on the right side of the parallel bracket

img:spring created on the left side off the paralle bracket.

img:Final model of the parallel bracket

Result and conclusion:

• extracted the mid surface on the either side of the bracket.
• Created material and the property for each bracket and assigned.
• Created RBE2 and RBE3 on (e,d,b,c) and (a).
• Created 1D element such as BAR,BEAM,ROD on the top of the three holes(a,b,and c)
• All the three 1D element are created as per the given dimension and Degree of freedom(DOF).
• Added mass of magnitude of 10 each on the either side(d and e) cross section of the bracket.
• Added spring element on either side og the bracket(e,d)

outcome:

• learned to create 1D elements such as rod,beam,bar and also learn how to extract the midsurface and meshing on the mid surface.
• learned how to assign material and property for each component.