Challenge

Week - 3 Drop test Challenge

Aim:

To Setup the given problem by using LS Prepost, solve by LS Run and Post process the results using LS Prepost.

Procedure:

First open the given input file. Click on File > Open > LS Dyna Keyword file. Open the file with .k extension.
Then the given input file is opened as shown in figure.

Fig: 1 Showing Initial model.

After click on the Keyword manager option in Model tab. This will displays the No of elements, Nodes, Parts details.

Fig: 2 Showing the initial model details ( no of elements and nodes)

After Define material for various parts. This can be done by clicking on Keyword manager option > All > MAT. This will display different types of materials. Examples like Elastic, Piecewise Linear Plasticity materials, Rigid etc. After selecting particular material type , key in all the material properties like density, poissons ratio, E etc. After Definition of the materials , these needs to be assigned to specific parts.

Fig:3 Showing the MAT input requirements.

Next step is to define the sectional properties which includes thickness assignment to Shell elements , ELFORM etc. Assign proper ELFORM depending upon whether it is shell or solid.

Fig:4 Showing the Sectional properties definition window

Next step is to assign the Defined materials and sectional properties to the various parts. This can be done by clicking on Keyword manager > model > part. Assign material and section properties to each and every part.Mat Rigid to be assigned to the wall to make it rigid.

Fig: 5 Showing the Mat and Sectional assignment to parts

After define the boundary conditions. In this case Mobile should be assigned with some initial velocity and floor should be rigid.
For giving initial velocity to the mobile, Click on Model and part > Keyword manager > create entity. In that click on initial > velocity. Check the direction in which velocity needs to be assigned to the model i.e., X or Y or Z. Click on create and given the velocity value in the Specific direction. In this case it is -Z direction and select the model by using box selection. Velocity is assigned for the model.

Fig :6 Showing the Entity creation tab for initial velocity.

Next step is to define contact between the two parts. This can be done by clicking Model and part > Keyword manager > Contact. In contact select Automatic surface to surface and select the wall as master and mobile as slave part.
Next step is to define the control cards. This can be done by clicking on Model and part > Keyword manager > ALL. In that click on control > Termination. A window will pop up in that end time needs to be given as input.
Last step is to call for OUTPUT. This can be done by clicking Model and part > Keyword manager > ALL > Database. Click on the d3plot and specify the timestep.

Fig :7 Showing the Output D3plot window

After all the parameters are assigned properly, Model check can be performed to find any errors in assigning anything.
The model should be run using LS-Run. After completion of Run, it should be opened in LS prepost for view the results. i.e., Post- processing.

Conclusion:

The given initial model is solved by assigning proper materials, boundary conditions and solved using LS-Run. The obtained are post processed using LS-Prepost.

Fig: 8 Showing the Initial model. Fig:9 Showing the final output file (showing stress in Z-direction)

Learning Outcomes:

Ship work like this
in your own course.