Week 4-1D Element Creation Challenge

OBJECTIVE:- Take a mid surface & mesh the given component & create 1d element 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:

• Import the model by using geometry option in the form of IGES format and delete the wireframe.

Creating the mid surface for the given component

• As the thickness of the given component is uniform, Select the component and create a mid surface for the top component (bracket 1) by making it current selection and select OFFSET method for midsurface.

• Select the component and create a mid surface for the bottom component (bracket 2) by making its current selection, select OFFSET method for midsurface.

• Then we assign the Material & properties to the midsurface component in the model browser.

Create Material:-

• We select steel as the Material for this component.

Creating the properties:-

Meshing the component:-

• To mesh the given component, we need to create washer splits near the hole region for a smooth mesh. Washer split offset we selected is 5mm.
• Generate the mesh with element size as 5mm with mixed element type.

Create the rigid at points a,b,c & d:-

• Create the RBE2 and RBE3 at the respective holes with the given DOF.
• We create RBE2 elements using rigids in 1D module for the first holes in top & bottom & we restrict the element to transitional DOF in X,Y & Z axis as mentioned for the first case. similarly for case 2 and case 3.

• We create RBE3 elements using rigids in 1D module for the first holes in top & bottom & we restrict the element to all DOF in X,Y & Z axis as mentioned for the second case.
• At last created RBE3 elements using rigids in 1D module for the first holes in top & bottom & restricticting the element to all DOF in X & Y axis as mentioned for the third case.
• Hence after creating RBE2 & RBE3 elements, creating the rod, bar and beam 1D elements at the respective node points.

• Once RBE2 & RBE3 created, we should create mass with the magnitude of 10 & type of mass should be given as CMASS1 for case d & e.

Creating cross sections for Rod, Bar & Beam:-

• To create the 1D element, we need to go the hyper beam tool and select the respective cross-section for creating the 1D element and give the assigned dimension to the geometry as mentioned in the specification.
• creating cross sections for the ROD in the form of thin wall box which has been given for the first case.

• Creating cross section for the BEAM in the form of I-section which has been given for the second case.

• Creating cross sections for the BAR in the form of Cross-section which has been given for the third case.

• Once cross sections are created, we need to create property for Rod, Beam, Bar with property cards such as PROD, PBEAM, PBAR.

• Mass is applied with the magnitude of 10 in RBE2 & spring elements are joined as been mentioned.

2-D element detailed representation:

Conclusion:-

• Extracted the mid-surface for the given component and Created a Mesh on the mid-surface.
• Deployed suitable 1D Element ( RBE2, RBE3, ROD, BAR, BEAM , MASS, SPRING etc ) to the respective places.
• Assigned Cross-section and property to the 1D elements.
• Created Solid representations of 1D Element.