Home / Examples / Stress Analysis [Galileo] / Example 32: Elastic Collision

Example 32: Elastic Collision

General

An object with an initial velocity collides with another still object. Transient analysis is performed.
The stresses and the deformations are solved.
Unless specified in the list below, the default conditions will be applied.

The stress-transient analysis is available in an optional package.

Analysis Space

Item	Settings
Analysis Space	2D
Model Unit	mm

Analysis Conditions

To simplify the simulation, the 2D model is created and analyzed.

[Large deformation] is selected, as it is expected.

Item	Setting
Solver	Stress Analysis [Galileo]
Analysis Type	Transient Analysis
Large Deformation	Select Large displacement

The transient analysis is set up as follows.

The time steps after the collision are smaller than those before the collision.

Tab

Setting Item

Settings

Transient Analysis

Table

Number	Calculation Steps	Output Interval	Timestep [s]
1	10	1	0.1x10-4
2	80	1	0.025x10-4

Graphical Objects

Circular sheet bodies represent objects.

Each side periphery is set with a contact boundary (contactor or contactee face), and they are paired in the [Boundary Pair] dialog box.

Body Attributes and Materials

Body Number/Type	Body Attribute Name	Material Name
0/Sheet	Body_Attribute_001	005_Polyurethane *
1/Sheet	Body_Attribute_002	005_Polyurethane *

(*) Available from the material DB

The initial velocity of the right object is set as follows. That of the left object is 0 by default.

Body Attribute Name

Initial Velocity

Body_Attribute_002

X Component: -100 [m/s]

Y and Z Components: 0 [m/s]

Boundary Conditions

Boundary Condition Name/Topology	Tab	Boundary Condition Type	Setting
Contactor/Edge	Mechanical	Contact Surface	Select [Contactor Surface].
Target/Edge	Mechanical	Contact surface	Select [Contactee Surface].

The contactor and contactee surfaces are designated as a contact pair in the [Boundary Pair] dialog box. In contact analyses, the contact surfaces must be designated as a boundary pair.

Results

The principal stress distribution at 1.5e-4 [s] is shown on the displacement diagram below.

Large deformations and stresses are exhibited around the contact area.

The chart below shows the velocities of 2 objects over time.

The blue and red plots are for the right and left objects, respectively.

The velocity is transferred from the right object to the left from 1.0e-4 [s] over to 2.0e-4 [s].

This is explained by the theory of elastic collision in which exchange of velocity takes place before and after the elastic collision between objects of the same mass on the straight line.

While the results displayed, on the [Show Results] tab

, click [Create Animation] . The animation file (.avi) will be created.