Challenge

Week 4-1D Element Creation Challenge

ABSTRACT:

Mesh the Given component with the Size of 5 Units. Create 1D elements on the following component with given cross-section and DOF

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

d. & e. Apply the mass of magnitude 10 with the RBE2 link

f. Join the two components with Spring elements

PROCEDURE:

Geometry clean-up and Mid surface generation:

Then clean up the geometry manually and check whether the components are connected properly and the surface is filled or not.
After checking geometry, proceed with the model to the mid surface by selecting Geometry > mid surface > and select the elements that you want to take mid surface.
In this model, we have two brackets and both are the same as each other while we taking the mid surface in hypermesh there are 4 options available to us. They are shown below in the picture.

Now remove all the solids using the delete option. Also, remove all the remaining components other than mid surface 1 and mid surface 2.

Organizing components in hypermesh:

After the mid surface is generated for the whole component. We can divide mid surfaces into n number of components.
1^st we need to create the components. I have created mid-surface 1 and mid-surface 2.
I will make mid surface 1 as the current component (right-click on the component and make it as current). Now go to tools > organize > select surfaces > click on the move.

Similarly, organize the 2^nd mid to mid surface 2 (component).
Create a washer split at the holes as these splits give us better mesh flow and rigidness at the holes.
Geometry > quick edit > washer split and enter the offset values as 5mm > click that hole to create the washer around the hole

Assigning Properties and Materials in hypermesh:

We can create properties and materials simply by right click > create > property or material.
I have selected card image as MAT1 for material, which is nothing but steel.
For properties, I have selected card images as PSHELL, as these are surfaces, and also assigned steel as their material.
Now go to the component section and assign property, then it will automatically take the material. Therefore, materials and properties are assigned to mid-surface 1 and mid-surface 2.

Mesh generation for components:

Now create the mesh for the two brackets by selecting 2D > auto-mesh > enter element size as 5mm> select the surface to create mesh on that surface

Connections:

Rigid elements are basically RBE2 elements. These elements have infinite stiffness. These elements never bend, rotate, or move. In RBE2, the load distribution is uniform irrespective of the position of the load.
I have created RBE2 elements at a, d & e respectively.
Similarly, create RBE2 elements at d & e.
In RBE3 elements, the load distribution depends on the distance from the load. Load distribution is more on the nodes closer to the load.
Now create RBE3 elements at b (all dof’s constrained)

Creating 1D elements in hypermesh:

1st create rod element at “a”. go to 1D > rods > select nodes > select element type as CROD

Similarly create bars at “b” and “c”. go to 1D > bars > select nodes > orientation > element type (CBEAM or CBAR)

Creating sections using hyper beam:

Now create Box Section at “a” with given dimensions (a= 12 mm, b=10 mm, Thickness t= 0.75 mm)
Go to 1D > Hyper beam > Standard section > select section library and type > Create
Then it will take you to hyper beam, where you can edit all the dimensions of the section which we have given.

Similarly create I section and X section according to the required dimensions. (create > standard selection > optistruct > CROSS for X section)

Assigning hyper beam sections to 1D elements(connections):

Create 3 separate properties for CROD, CBEAM, and CBAR.
Now assign the box, I, X sections to the required 1D elements. This process is shown below figures.