Assignment 3

Object: The main objective is to run the base simulation and compare the base simulation with the improved simulation by applying shell element properties.

Hourglass energy:

Hourglass ( HG ) modes are nonphysical, zero-energy modes of deformation that produce zero strain and no stress. Hourglass modes occur only in under-integrated (single integration point) solid, shell, and thick shell elements.

Two methods used to control the formation of hourglass energy.

1. Perturbation (Q4 elements)

2. Physical stabilization (QEPH elements)

Internal energy:

The internal energy of a system is the energy contained within the system.

The internal energy of a system can be increased by the introduction of matter, by heat, or by doing thermodynamic work on the system. When matter transfer is prevented by impermeable containing walls, the system is said to be closed and the first law of thermodynamics defines the change in internal energy is the sum of the heat added to the system and the thermodynamic work done by the surroundings on the system. 

Kinetic energy:

the kinetic energy (KE) of an object is the energy that it possesses due to its motion.

 It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. 

 The kinetic energy of an object of mass m traveling at a speed v is  .

The below procedure we are following to run the base simulation.

1.Using the crash beam file from the previous assignment, change the run time to 55 ms.

/VERS/120
/RUN/First_Run/1/
55.0000000000000
/ANIM/VECT/DISP
/ANIM/VECT/VEL
/ANIM/ELEM/EPSP
/ANIM/ELEM/ENER
/ANIM/ELEM/VONM
/ANIM/ELEM/HOURG
/ANIM/DT
0.000000000000000 1.00000000000000
/PRINT/-10
/TFILE/0
0.100000000000000
/RFILE
5000
/ANIM/NODA/DMAS
/DT/NODA/0
0.900000000000000 0.000000000000000

2. Change the number of animation steps during simulation to a minimum of 25 and maximum of 60.

The above figure shows we are changing the number of animation steps during simulation to a minimum of 25.

3. Run the base simulation without any modification to element properties.

The process starts with the importing starter 000rad file by using import solver disk.

Without changing the element properties we run the simulation by using -nt 4.

After running the simulation the data is generated animation file, to1, and .h3 file, etc all the information is saved in the new file.

After running the simulation we move to Hyperview window in that case we are importing the .h3 rad file. This file contains the simulation data.

After simulating the process we move to the Hypergraph 2D panel. In this, we are creating the graph according to the given boundary conditions like Internal energy, Kinetic energy, Hourglass energy, and contact energy. After applying the conditions we run the simulation, we get the graphs as shown below.

Displacement:

After running the simulation without applying the boundary conditions we get the displacement of maximum 8.193e+2 and the minimum is 0.

Time VS Time step:

Time VS IE, KE, HE & TE Graph.

The above graph shows the time VS IE, HE,& TE. in the graph shows the with respect time internal energy and hourless energy increasing from o at the same time KE and TE decreasing from 6.0 e+7.

1. The rigid body fixed at one end. So the initial velocity starts from the rigid body which hits the rigid wall at the other end.

2. The internal energy stored in the body after heating the other end of the rigid body. The internal energy starts increasing from the 0.

3.  The kinetic energy starts with the 6.e+7 before hitting the rigid body & strat\'s gradually decreasing after hitting the rigid body. 

4.  Hourglass energy (zero energy deformation nodes) is increasing with time resultant force is more obtained.

5. Initial deformation of the rigid body is more goes on decreasing. 

4. At the end of the simulation, do the energy error and mass error checks and determine whether results would be acceptable.

At the end of the simulation, we get the energy error is -11.0%.

The actual limit energy error value should be - ve and < 5% is good.

At the end of the simulation, we get the mass error is 0.1659E-03.

The actual limit mass error value within 10% is good.

Comparing both values with the standard value this simulation is good.

6. Change all the shell elements properties to recommended properties, save this as separate, rad files and run the simulation.

This simulation process is similar to the previous process in this case we are adding the properties to the components. The below image shows the given properties.

After applying the properties to the components as shown in the below images.

Displacement graph:

After running the simulation with applying the boundary conditions we get the displacement of the maximum of 7.868e+2 and the minimum is 0.

Time VS Time step:

Time VS IE, KE, HE & TE Graph.

The above graph shows the time VS IE, HE,& TE. in the graph shows the with respect time internal energy and hourless energy increasing from o at the same time KE and TE decreasing from 6.0 e+7.

1. The parameters of the element are changed according to the given parameters.

2. In this case, hourglass energy and total energy are not changing with the global variable after 40\'s the hourglass energy start varying.

3.The internal energy stored in the body after heating the other end of the rigid body. The internal energy starts increasing from the 0.

4. The kinetic energy starts with the 6.e+7 before hitting the rigid body & strat\'s gradually decreasing after hitting the rigid body. 

5. The displacement at the free end is more.

At the end of the simulation, do the energy error and mass error checks and determine whether results would be acceptable.

At the end of the simulation, we get the energy error is -6.0%.

The actual limit energy error value should be - ve and < 5% is good.

At the end of the simulation, we get the mass error is 0.1659E-03.

The actual limit mass error value within 10% is good.

Comparing both values with the standard value this simulation is good.

Result:

1. After applying the parameters in the second case we are getting better simulation results. 

2. Comparing both simulations the HE & TE are changing with global varials in the first case. 

3. The resultant force is very high in the critical area as compare to the normal area.

4. The curved section in a beam not deforming suddenly.