The comparison of the base setup simulation results and different kinematic condition simulation results

Objective:

To compare the base setup simulation results and different kinematic condition simulation results and run the simulations as per the below cases,

1. Run the crash tube model.
2. Change the value of Inacti=6 and run it.
3. Create the type 11 contact and run.
4. Remove both notches and remove boundary conditions on a rigid body node then run.
5. Create a new notch in the middle, select the whole section and run.
6. Create a new notch with nodes only from opposing 2 faces and run.
7. Mesh the Bumper Assembly with element size is 6mm.

Case and report:

INTERFACE:

The interface is defined to model how parts interact when they come into contact with each other.

The interface is consists of many interface types and we gonna look after some of the majorly used interface types and they are,

• TYPE 2 – Tide node to surface.
• TYPE 7 – General node to surface.
• TYPE 11 – Edge to Edge.
• TYPE 19 – TYPE 7 + TYPE 11.
• TYPE 24 – General node and surface to surface.

Case 1 ­: Run the crash tube model

• Initially, Crash_tube_0000.rad file opened in HyperWorks to run the simulation.
• The base simulation is run without changing any material properties then send it radioss profile.
• After that simulation to check the energy Rwall forces, internal and kinematic energy, Contact forces and time history, %of energy error and mass error.

FIG 1a Comparision of Global variables

FIG 1b Comparision of Node/TH Node

FIG 1c Comparision of Rigid wall/ rigid wall Force

FIG 1d Simulation of initial run_1

Report:

1. running the simulation crash tube strike the rigid wall at the dynamic max. values of 29.685 joules with the dynamic min. values starting from 0. and internal energy was increase through the simulation with max. values are 87.830 joules noticed in 30ms.
2. kinematic energy decrease with time 27ms and values is 27.689 joules after it increased slowly. the contact energy was high during the crash tube and the wall was in total energy observed directly.

Case 2 : Change the Inacti value

• This time to change the inacti value and run the simulation. The base simulation is run with changed the values of Inacti=6 then send it into radioss profile and simulation is runs.
• After that simulation to check the energy Rwall forces, internal and kinematic energy, Contact forces and time history, %of energy error and mass error.

FIG 2a Comparision of global variables

FIG 2b Comparision of Node/TH Node

FIG 2c Comparision of Rigid wall/ rigid wall Force

FIG 2d Simulation of run_2

Report:

1. Inacti has been set 6 running the simulation of the crash tube strike to get the max. dynamic values are 34.710 joules with starting the min values is 0.
2. The internal energy was increase through the simulation with max. values are 87.830 joules noticed in 30ms.
3. kinematic energy decrease with time 27ms and values is 28.689 joules after it increased slowly. the contact energy was high during the crash tube and wall were in total energy observed directly.

Case 3 : Create the type 11 contact and run

• In this case, it is to create a Type 11 contact interface in HyperWorks to run the simulation.
• Type 11 is identifying master node and slave node it means edge to edge contacts.
• After that simulation to check the energy Rwall forces, internal and kinematic energy, Contact forces and time history, %of energy error and mass error.

FIG 3a Comparision of global variables

FIG 3b Comparision of Node/TH Node

FIG 3c Comparision of Rigid wall/ rigid wall Force

FIG 3d Simulation of run_3

Report:

1. Edge to edge contact interface is a major role in penetrating the element from the beginning to the end of the simulation. The internal energy was increasing at the simulation in 30ms.
2. kinematic energy decrease with time 27ms and values is 28.689 joules after it increased slowly. the contact energy was high during the crash tube and the wall was in total energy observed directly.

Case 4 : Remove both notches and remove boundary condition on rigid body

• This case is the nodes in the crash tube nodes are aligned in a way to make sure there are no notches in the component.
• The base simulation is run to remove the notches and remove the boundary condition and align the nodes, then send it radioss profile.
• After that simulation to check the energy Rwall forces, internal and kinematic energy, Contact forces and time history, %of energy error and mass error.

FIG 4a Comparision of global variables

FIG 4b Comparision of Node/TH Node

FIG 4c Comparision of Rigid wall/ rigid wall Force

FIG 4d Simulation of run_4

Report:

1. The notches are removed at the component then running the simulation, the results is less energy is required for the crash tube to hits against the wall. The internal energy was increasing through maximum energy at 30ms.
2. Kinematics energy decrease 27ms the value is 27 joules. the change in energy has been observed from the above cases.the contact energy was high during the crash tube and wall were in total energy observed directly.

Case 5 : Create a new notch in the middle

• This case is the nodes in the crash tubes are aligned in the way there are no notches in the component.
• And new notch is created in some elements by doing the element offset on the selected elements and align the nodes, then send it radioss profile.
• After that simulation to check the energy Rwall forces, internal and kinematic energy, Contact forces and time history, %of energy error and mass error.

FIG 5a Comparision of global variables

FIG 5b Comparision of Node/TH Node

FIG 5c Comparision of Rigid wall/ rigid wall Force

FIG 5d Simulation of run_5

Report:

1. The notch was created in the middle by removing the default notch, and clear change in energy has been observed during the simulation. The internal energy was increasing through maximum energy at 30ms.
2. Kinematics energy decrease 27ms the value is 28.059 joules. the change in energy has been observed from the above cases. The contact energy was high during the crash tube and the wall was in total energy observed directly.

Case 6 : Create a new notch in the opposite faces and run

• In this case, a new notch in some elements its followed in the opposite faces by doing the element offset on the selected elements then send it radioss profile.
• After that simulation to check the energy Rwall forces, internal and kinematic energy, Contact forces and time history, %of energy error and mass error.

FIG 6a Comparision of global variables

FIG 6b Comparision of Node/TH Node

FIG 6c Comparision of Rigid wall/ rigid wall Force

FIG 6d Comparision of contact forces

FIG 6d Simulation of run_6

Report:

1. The notch was created in opposite faces on the selected elements in master segments, so change the energy has been clearly noticed while running the simulation. The internal energy was increasing through maximum energy at 30ms.
2. Kinematics energy decrease 27ms the value is 28.059 joules. the change in energy has been observed from the above cases.the contact energy was high during the crash tube and wall were in total energy observed directly.

Case 7 : Mesh the Bumper Assembly:

• Open the Bumper_system.hm file.
• Then meshed that components with elements size are 6mm
• And connection has been made between the components using 1D connectors.

FIG 7a Meshed component Bumper assembly

FIG 7b Meshed component is connected with each other using 1D Connector

Conclusion:

1. simulation of all the six cases mentioned below are simulated by the required parameters,
   1. Run the crash tube model.
   2. Change the value of Inacti=6 and run it.
   3. Create the type 11 contact and run.
   4. Remove both notches and remove boundary conditions on a rigid body node then run.
   5. Create a new notch in the middle, select the whole section and run.
   6. Create a new notch with nodes only from opposing 2 faces and run.
   7. Mesh the Bumper Assembly with element size is 6mm.
2. And each case in the simulation where some effects on the notches are particularly interpolated in the results.
3. Type 11 contact interface created an edge to edge contact between the surface.