Assignment 5-RADIOSS Interfaces & Study of Effect of Notches Challenge

Aim :

This challenge is about the study of notches in a component and comparing it with the component without notches.

Objective :

The study of notches in a component explains about the behaviour of component with notch and without notch.

In Hypermesh it is asked to perform basic operations like pasting the material by using proper command and to apply connections at the required places.

In the given component the few parts are not attached to the crash box for that we use the basic option project point and replace point.

After making a proper crash box geometry we have to make connections which is very important during analysis. We have connected the crash box to the bumper by spot weld and the gap between crash box is connected using seam weld.

Case 1

To run the simulation in RADIOSS and to select the required output while processing the analysis.

And save the results as case 1 to visualise and to get the plots that required for the result.

The given model is a type7 interface. Which is a general pupose interface can simulate all types of impact between a set of nodes and surface.

From the graph we can notice that the Internal energy increases when the kinetic energy decreases. Total energy reduces when contact energy increases. In rigid wall force there is sudden raise in graph where the tube is completely crushed.

Case 2

In this case we change the value for Inacti = 6 and run the file to get the changes that happens in the analysis.

Here we set the value for Inacti = 6 this will remove initial penetration and it will reduce the defined gap. There is no changes made in the crash tube so the result graphs are similar to the case 1.

Case 3

In this case we create the Type 11 contact for that we create a new contact and we define the default values requried for the simulation.

Here also the geometry is same and we have changed the contact to type 11 and we ran the analysis and got the result files similar to the above cases. In rigid wall force graph we can notice a higher value to crush the crash box.

Case 4

Here it is asked to make the geometry aligned flat in all side of surfaces and we uncheck all the boundry conditions to run the simulation.

In this case the result graphs which we got are similar to the previous cases.

Case 5

Here it is asked to create a middle notch throughout the tube and run the simulation.

Case 6

Here in this case it is asked to perform the simulation with opposite face notchs and run the analysis.

Conclusion :

For all the six cases we did't apply any external value load from our end it is automated so all the output graphs are similar to each other and due to the changes that we made in the geometry of the crash tube we can notice a change in von mises stress values that is tabulated below.

Case	Stress values
Case 1	6.949e-01 Kg/mm^2 (Given model) (0.06 Mpa)
Case 2	6.949e-01 Kg/mm^2 (Inact =6)
Case 3	6.451e-01 Kg/mm^2 (Type 11)
Case 4	6.076e-01 Kg/mm^2 (Flat surface with zero dof)
Case 5	6.923e-01 Kg/mm^2 (Middle notch in all the faces)
Case 6	6.485e-01 Kg/mm^2 (Middle notch in two faces opposite to each other)