Week - 3 Drop test Challenge

 Drop test Challenge

Aim: - To create a complete simulation file to perform a drop test from a given basic .k file consisting of only nodes and elements. Essential keywords should be added to create a basic solver deck to simulate a drop test.

 Given: -

Procedure: -

Open the LS-PrePost and open the given keyword file.

Parts: -

1. The given input file consists of three different parts the bottom plate of shell elements, the mobile phone of solid elements, and the bottom plate of solid elements. We can either model the test with a bottom plate as a shell or solid elements.

For this analysis, we have to consider the mobile phone and bottom plate with solid elements formulation and deleted the extra part ‘bottom plate’ which was modeled with shell elements.

Material: -

1. Now, define the material for both parts. Select 020-MAT_RIGID material to define for the bottom plate. Select 024-PIECEWISE_LINEAR_PLASTICITY material card for defining the mobile phone.

2. Define material properties like mass density, Young’s modulus, Poisson’s ratio, and other required quantities for both the material cards.

Section: -

1. Similarly, define section card for assigning element type as solid. Select *SECTION_SOLID card and define the required properties.

Boundary: - 

1. Now, assign proper boundary conditions to the parts. This can be done by going through creating an entity and selecting the required boundary conditions.

2. The bottom plate is fixed by constraining the boundary elements of the plate in all degree of freedom. The selection of nodes is done by area. Boundary>Spc(Single point constraint) option is utilized for defining this boundary condition.

Initial Velocity: - 

1. Similarly, the velocity of -13mm/ms is given through the *INITIAL_VELOCITY card available in create entity toolbar. The mobile phone is selected by picking the part option.

Contact: - 

1. The contact between the two parts is an important parameter. This is defined by the *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE card. The slave segment (SSTYP) and master segment (MSTYP) set type is defined as part ID. The slave segment is defined as a mobile phone and the master segment is defined as the bottom plate.

 Control Termination Card: - 

1. The termination time for the problem is defined by the *CONTROL_TERMINATION card. The distance between the mobile phone and the bottom plate is calculated and the approximate time taken to hit the bottom plate and some additional time after the impact is calculated. This cumulative time (2 s) is defined as termination time in the card.

Database: - 

Now after all conditions and termination details, we can generate output requests or results that we want from the analysis.

For that, we have to create cards for output. For animation and other part-related data, create “BINARY_D3PLOT”, from the database and “GLSTAT”, and “MATSUM”, from ASCII_option in the database.

Here we have given the time 0.1 ms for reporting all the data at each 0.1 ms from 0 to 20 ms for accuracy.

After the creation of all necessary cards, save the Keyword file with the “.K” extension.

Calculation:

Timing Information:

Results:

Open the Binary “d3plot” file in LS-PrePost and check the results.

Effective Von-mises Stress:

Global Energies:

From the above image, we can say that, when the Phone touches the Rigid Wall, Kinetic energy decreases and Internal Energy Increases.

Conclusion: -

The complete simulation file (keyword file) has been generated from the given primary file. A solver deck has been created to perform the mobile phone drop test with post-processing data.