Project 1 - Impact of Ball on Wall

Aim:

To observe the collision of aluminum alloy plate with steel ball at different velocities and find out the total deformation.

Solution:

Step 1:

Model a plate with dimension 100*100*5 mm and a steel ball of diameter 10mm which are 10mm apart. Mesh these components using ANSA and output as key file.

Step 2:

Open LS Prepost and import the key file. Kg/mm/ms unit system has been used. Create material cards.

Ball material:

density = 7850 kg/m3 = 7.850e-6 kg/mm3

E = 210 kg/mm.ms2

Poisson ratio = 0.3

Mat elastic material card is used to create structural steel material.

Plate:

density = 2.77e-6 kg/mm3

E = 71 kg/mm.ms2

Poisson ratio = 0.33

Yield strength = 0.28 kg/mm.ms2

Tangent modulus = 0.5 kg/mm.ms2

Failure stress = 0.47 kg/mm.ms2

Mat 24 - Piecewise linear plasticity material card is used to define the plastic region in addition to elastic region.

Step 2 :

Define the section,

As the box is converted to mid shell mesh, thickness is assigned as 5mm. For the ball the thickness is assigned as 1mm (default for outer mesh).

Step 3: Boundary condition:

Create node set to constrain the edges of the plate using model>create entities>set>set nodes.

Now go to keywork>boundary>spc_set>select the node set>constrain all six degrees of freedom.

Applying velocity to the ball:

case 1:

velocity = 50 mm/ms

Create node set to apply velocity at all nodes of the ball using model>create entities>set>set nodes.

go to keyword>initial>velocity>enter the value.

Step 4: Contact:

Automatic surface to surface contact is defined between the plate and the ball select plate as surface A as it is deformable and ball as surface B as master below.

Automatic single surface contact is defined to avoid internal penetration of the ball.

Step 5:

Control Termination :

time of impact = distance/speed = 10/50 = 1/5 ms - Thus end time must be greater than the impact time.

Step 6:

Database > ascii card> Select GLSTAT, Nodout, Eleout and Binary_D3PLOT to record the animation.

Result:

Resultant displacement = 0.703mm

Effective plastic strain:

For Case 2:
Velocity of the ball = 250 mm/ms

Resultant displacement = 4.17 mm

Effective plastic strain:

Case 3:
Velocity of the ball = 500 mm/ms

Resultant displacement = 11.2 mm

Effective plastic strain:

Conclusion:

Thus the simulation of collision of ball with plate at different velocity has been performed and the total displacement has been recorded at each case.