Week-7 Head Impact

G-DRIVE URL:https://drive.google.com/drive/u/0/folders/1S18pT4BTUAOJ-_CcfmpdcvvKG5dY2Guq

EUROCAP_HEAD IMPACT PDF LINK:https://cdn.euroncap.com/media/41769/euro-ncap-pedestrian-testing-protocol-v85.201811091256001913.pdf

Aim:

Performing the head impact teat with various type of method such as simple shell sphere, head impacting with the rigid wall and head impacing with the car hood. from the analysis calculating the various HIC (head injury co-efficient).To estimate the potential risk of head injury in the event of a vehicle striking an adult or a child, a series of impact tests is carried out at 40 km/h using an adult or child head form impactor. Impact sites are then assessed and the protection offered is rated as good, adequate, marginal, weak or poor.

CASE-1 Simple sphere model

Model_setup

• Material assign
• section assign
• rwall creation
• velcoity assign

MATERIAL ASSIGN

• the material property is al99

SECTION ASSIGN

• Secting the elform as 2 an the thickness is 5

RWALL CREATION

VELCOITY CREATION

• the velcoity of sphere is -11.11 in z direction in mm/ms which equal to 36.6 km/hr

RESULT

CASE-2(HEAD HIT ON RWALL)

In case 2 we want to rotate the head in 45 degree with out disturbe the main head file. that is done by using such include transform cards in before using the include transform card we use the define transform

which trans id and define the type of transformation and its aixs

RWALL CRAETION

VELCOITY CREATION

• the velcoity of sphere is -11.11 in z direction in mm/ms which equal to 36.6 km/hr

CONTACT CREATION

• In contact defination the slave is head node

Result

• the HIC vakue is 8.179e4 at the time of 1.5 to 2.4 A HIC-36 (meaning a measure of impact over 15 milliseconds) of 700 is estimated to represent a 5 percent risk of a severe injury.At a HIC of 1000, there is an 18% probability of a severe head injury, a 55% probability of a serious injury and a 90% probability of a moderate head injury to the average adult.so from this value the injury is ver high
• The above graph explain is the time of upto t=0.90 there is no contact between the rwall and head so, it is stright horzontal line but the after the t=0.9 time step the head contact between the rwalll and head it indicate the graph line are increase t=0.99 at time slightyly decerese duto the deformation but still velcoity is acting the head same time the head still contact the rwall so, the head material is undergoing the stress contiunely.at t=2 ms the the head get peak stress which having the 0.0236gpa after that it rebounce and decerease get remains conatant.
• as same the strain increase the gradual and after impact the head is not get it orginal postion some of the deformation is occur so, thet the graph is t=3 the strain value0.006 is constatnt.the max strain is 0.013
• the graph shwing the the max accelaertion of the head form the max acceletaion is14.729 which include the gravity also. after impacting the energy is despating so, the acceleration also reduced

CASE-3(HEAD IMAPCTING THE HOOD )

In case 2 we want to rotate the head in 45 degree with out disturbe the main head file. that is done by using such include transform cards in before using the include transform card we use the define transform

which trans id and define the type of transformation and its aixs.and additionaly include the hood also..

the given mesh hood file is not in material property so, we first create the include file for mesh file from that we add the material property as aluminam so,we do not change the main file of mesh file and same as we rotate the head model

And we create the new file in the name of end file in that we adding the newly created file such like mat and rot file

• haed is rotated with 45 degeree with y axis
• the material al is added the sub system is mat file with out disturbing the main file

MAIN END FILE

• INCLUDE the such rotated head,mat hood files
• the velcoity of sphere is -11.11 in z direction in mm/ms which equal to 36.6 km/hr
• the automatic surf_surf_contact is created the slave is hood and the master is head. the slave and master descide in the form of which is hit and which is deform.

RESULT

• as per the euro ncap hic<650 is green that means there minor injury with the head and the HICd is 395.6
• for more information pls use the link:https://cdn.euroncap.com/media/41769/euro-ncap-pedestrian-testing-protocol-v85.201811091256001913.pdf
• the t=0.9 the stress is 0 that indicate the the head is not hitting the model after t=0.99 there contact between the head and hood so the head parts acting the fore so, that the stress in creased after some time it will very slightly reduced bet not in fully reduced with case-2 it indicate the hood is deformoing and the stress of the head still present in the head.the max is stress is 0.16gpa
• in this graph which clearly indicate the head not undergoing the any deformation but only deform the hood part
• the graph shows the time 1.6 there no contact between the hood and head so the accleration constant after t=4.40 the accleration is 530.56mm/ms2 the neagative is axis direction.

COMPARSION OF CASE_2(RWALL) AND CASE_3(HOOD)

NAMES	CASE-2	CASE-3	REMARKS
HIC VALUE	8.179e4	304	as per eurocap hic<650 is green (safe)
STRESS	0.0236gpa	0.16gpa	the hood deformation is high.
strain	0.013	0	in case-3 the deformation is hood only
ACCELERATION	14.9 mm/ms2	530.56mm/ms2

conculsion

in this assignment we learn the various case-3 of head impact test and obtaing the post processor result

in this assignment we learn the include cards define cards and transformation cards also

in this assignment we learn various hic calculating value and it protocals