Week-7 Head Impact

AIM:

To create a simulation between various models and claluate the HIC value under various below mentioned cases.

1.) between a simple head form and a rigid wall

2.) between a standard developed pedestrian headform and a rigid wall.

3.) atlast between the pedestrian headform and the meshed hood model.

PROCEDURE

CASE 1: SIMPLE HEAD MODEL IMPACT AGAINST RIGID WALL

import the model simple headform into lsprepost

create the rigidwall under create entity, it is set with distance of 15mm from the bottom surface of the head.

assign the boundary conditions by setting the motion free in the z direction.

create a automatic single surface card under contact keyword and set the head form as the slave part.

provide the initial velocity of impact in the -ve z direction.

input the material properties into the keyword mat 24 piecewise linear plasticity

assign the shell section property for the headform

the termination time is set as 20 ms and the d3 plot is set as wanted for eg:0.5ms

the value of dt for the ascii options such as nodout, glstat, rwforce are provided as 0.5

after the model check the model is set to run in the ls program manager, by obtaining a normal termination the d3plot is set to animation and the graph is ploted.

EFFECTIVE STRAIN

EFFECTIVE STRESS

CASE 2: IMPACT OF PEDESTRIAN HEADFORM WITH RIGIDWALL

Import the pedestrian headform and create the rigidwall

the keyword define transformation is used to rotate the headform into to an angle suitable for impact. As it would depict a real life simulation as per the automotive indian standard.

the keyword include transformation is used to include the file which needs to subjected to transformation and it is assigned by the tranid

create the rigid wall normal to the bottom face of the rotated headform

create the control termination card and assign the ascii keywords required such as nodout, glstat, rwforce.

the database history node id is set as shown below

after the model check the model is set to run in the ls program manager, by obtaining a normal termination the d3plot is set to animation and the graph is ploted.

EFFECTIVE STRAIN

RESULTANT ACCLERATION

HIC

CASE3: PEDESTRIAN HEAD FORM IMPACT MESHED HOOD.

Import the model into lspre post

do not alter any other control files and include the meshed hood file using include keyword as shown below

material properties of aluminium is provided to the hood

create an automatic surface to surface contact card stating the headform as the slave part and the hood as master part

set the initial velocites and the degrees of freedom as required.

create the control termination card and assign the ascii keywords required such as nodout, glstat, rwforce.

after the model check the model is set to run in the ls program manager, by obtaining a normal termination the d3plot is set to animation and the graph is ploted.

EFFECTIVE STRAIN

RESULTANT ACCLERATION

HIC

CONCLUSION:

Hence all the geometric models are subjected to simulation and the results where submittted in the form of graphs

All the three cases where analysed and report has been filed for information.