Week 4-1D Element Creation Challenge

The report of the challenge in ms word doc is attaching herewith.Pls go through.

WEEK 4 1D ELEMENT CREATION CHALLENGE

REPORT

Objective

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

1. 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

1. 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

1. Bar element:-  Constrain only xand 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

1. & e. Apply the massof magnitude 10 with the RBE2 link
2. Join the two components with Spring elements

Procedure

1.Import the model to hypermesh software.

2.The midsurface of the solid bracket model is extracted for both top and bottom brackets separately and named as top bracket and bottom bracket separately and 1D element was created.

3.Using the geometry topology and cleanup tools,some geometry clean-ups were done and the below model was obtained.

Figure 1:Midsurface created on top and bottom brackets

4.Using Automesh in 2D surface ,create the mesh of element size 5 ,starting from the stress concentration element areas like around the holes.

Figure 2: Meshed after geometrical cleanup

5.RBE 2 link was created around the first hole and a link was created and assigned rod to that element and the required translational degrees of freedom was assigned.

Figure 3: RBE2 link created with constrained translational dof

6.Similarly, RBE3 link was created around the second hole and a link was created and assigned bar element to that.

Figure 4: RBE3 link created with all dof constrained in all directions

7.Similarly, for the third hole, RBE3 link was again created and a link was created and beam element was assigned to it as per the question.

Figure 5: RBE3 Link created with dof constrained in x and y directions

8.Inorder to give the cross sections to the 1D elements, we took hyper beam, and in that the cross sections of each was provided as per question.

9.Now by using Bar and Rod tools in 1D, the corresponding cross sections were assigned.

Figure 6: I section from optistruct standard I section for beam element

Figure 7:Thin walled box section from hypermesh standard section for rod element

Figure 8:Cross section from optistruct cross for bar element

10.The respective cross sections were attached to the beam sections.

11.Mass of 10kg is asked to attach to sections D and E,which is done by selecting masses from 1D and then masses are attached to the respective nodes on both brackets as shown below.This is done using CMASS1 element.

Figure 9: mass allocation

12. The springs are connected at the F part of the model and the stiffness is provided in Y direction using CELAS1.

Figure 10: Spring element defined

13.Now the final model was made as below.

Figure 11: Final views of the model

Inference and Result

The above model was finally obtained.

 And the main study objective of forming 1D elements with specified cross sections and dof was fulfilled.