SimScale CAE Forum

FE Simulation on F1 Halo

** Abstract:**
The halo is a driver crash protection system used in open-wheel racing series which consists of a curved bar placed to protect the driver’s head. The system was introduced in 2015 and became mandatory according to FIA homologation and regulation from 2018. The first tests with the prototypes equipped with the system were carried out in 2016 and in July 2017. Since the 2018 season, the FIA has made the halo mandatory on every vehicle in Formula 1, Formula 2 and Formula 3 as a new safety measure. In this project, F1 halo is simulated in two different static load condition and trying to find stress and total displacement on the surface.

Construction:-
The system consists of a bracket that surrounds the driver’s head and is connected at three points to the vehicle frame. The component is made of titanium and weighed around 7 kilograms in the version presented in 2016. The weight rose to 9 kilograms in 2017. The system is not developed by the teams, but is manufactured by three approved external manufacturers chosen by the FIA and is the same specification for all vehicles. In a simulation performed by the FIA, using the data of 40 real incidents, the use of the system led to a 17% theoretical increase in the survival rate of the driver.
02e63aea263ea7cbfe77cbe5338a73b9_edited
fig:- halo image


Fig:- Cad Model of halo

MESH:-
Meshing type =Tet-Dominant
sizing = Automatic mesh sizing
Fineness = very fine


Fig: meshing of F1 Halo

Material :
It all starts with titanium. Lots of titanium.

“We had to buy about 10 tonnes of high-strength titanium within one-and-a-half months, and receive it all in time and in perfect quality,” says Steffen Zacharias of Germany’s CP Autosport, one of the three manufacturers chosen by the FIA as official suppliers of the new Halo safety device.


Fig: material apply to f1 Halo part

Boundary Condition:

  1. fixed support:- in halo there is total 3 part which is connected to the frame of the car.


    Fig: fixed support

  2. Static Test 1:
    A load equivalent to 116kN vertically downward and 46kN longitudinally rearward must be applied at a position 190mm rearward of the front fixing axis and 170mm above the front fixing axis and positioned on the AFP center plane.

  • There must be no structural failure of any
    part of the structure.
  • When the applied load on the structure
    has reached 125kN, the deflection must
    not exceed 17.5mm.
  • Permanent deformation of the structure
    must be less than 3mm after the applied
    load has been released for 1 minute.
    Permanent deformation will be assessed
    by an appropriate dimensional
    inspection



Fig: Static Test 1

3)Static Test 2:
A load shall be applied laterally inward and longitudinally rearward in an initial ratio of 1.12:1 respectively. This load must be horizontally applied at a position 385mm rearward of the front fixing axis and 150mm above the front fixing axis to the outer surface of the structure.

  • The peak load must not be less than
    125kN.

  • There must be no structural failure before
    125kN.

  • The deflection must not exceed 45mm
    before 125kN.


Fig: - Static Test 2

SIMULATION RESULTS:
1) Static Test 1:
F1 HAlo was practically simulated by the organization.
PNG
Fig: Halo on a Test bench.
Total Displacements results1:

2)Static Test 2:
PNG
fig: Halo on a Test bench.

Total Displacements results 2:

Conclusion:
In Quasi-static Test 1 rule set by FIA was said “Permanent deformation of the structure must be less than 3mm after the applied load”. and from the above FEA Simulation static Test 1, the Maximum displacement of the object was 2.032 mm which was under the limit.
For Quasi-static Test 2 the maximum displacement of the part was 7.7577 mm which was under the limit of 45 mm before 125 KN load.

Impormants of F1 Halo:
4F6B987400000578-0-image-m-21_1535362326291


Fig: Leclerc car after crash
References :
1)https://en.wikipedia.org/wiki/Halo_(safety_device)
2)https://www.fia.com/news/how-make-f1-halo
3)https://www.fia.com/sites/default/files/fia_standard_8869-2018_afp_v1_0.pdf
4)https://www.autosport.com/f1/news/138440/fia-working-on-better-looking-halo-for-2021

6 Likes

Wow Rohit, I am impressed!! Very good job buddy :hushed: :slight_smile:

1 Like

Thank You sir :star_struck:
but there was problem, when I click on form same page open again. @jousefm help me.
thank you,
rohit.

I see you have used a fixed support for the front joint to the frame but the testing image shows more like a pinned joint. Why the inconsistency?

hi @DaleKramer sir,
I was used fixed support because only I was found the only one bc related to the application(testing image).
Screenshot%20(278)
you can also suggest me another thing to do pinned joint.
thank you for this suggestion :raised_hands:

Sorry, I have not much FEA knowledge, but I am sure there is a way.

Perhaps @BenLewis could help here …

Hi Rohit,

my colleague Sebastian fixed the form, it should work now :slight_smile:

Cheers!

Jousef

1 Like

thank you sir :grinning:

Nice project @ROHIT_SR!

For the “pinned support” you can use a “remote displacement” . Just set the remote point into the center of the pin and free the rotation around the axis direction.

One additional hint: instead of using a “very fine” 1st order mesh, you could increase the result accuracy by getting a bit coarser on the fineness and use a 2nd order mesh instead.

Best,
Richard

2 Likes

Hi @ROHIT_SR,

@rszoeke bet me to it, but for what it’s worth I have copied your project and modified it to demonstrate how to model a pin joint. You can see my modified project here:

https://www.simscale.com/projects/BenLewis/f1_halo_-_custom_machines/

Please take a look at the following simulations:

  • Static test 1 - Run 2 D_z fixed
  • Static test 1 - Run 3 D_z free
  • Static test 2 - Run 3 D_z fixed
  • Static test 2 - Run 4 D_z free

The “D_z fixed” runs have the front pin translation in the z-direction fixed.
The “D_z free” runs have the front pin translation in the z-direction unconstrained.

How the pin translates in real life depends on how stiff the cockpit structure is relative to the halo structure. If the cockpit is much stiffer than the halo then the front pin will act as though its translation is fixed. If the cockpit is much more flexible than the halo then the front pin will act as though its translation is free. If the stiffnesses are about the same then the front pin will partially resist translation but not completely. In this case the stiffness of the cockpit structure will need to be modeled to get accurate results.

As a guide the front pin translates by about 12 mm under 116 kN of longitudinal load when it is unconstrained.

6 Likes

Gut feeling says the test setup looks pretty rigid and would translate much less than 12mm and that is a setup used to approve different manufacturers I suppose :wink:

1 Like

Agreed, but I suspect that the cockpit on the vehicle would be significantly more flexible than the test rig.

1 Like

hi sir,
SORRY FOR LATE RESPONSE. :sweat_smile:
all point are rigidly attached to the cockpit.
f1

so, I don’t think there is any pinned joint in the cockpit BECAUSE the total displacement should be less than the 3 mm in case 1 and less than 45 mm in case 2.
(correct me if it’s wrong) @DaleKramer @rszoeke @jousefm

LINK

THANK YOU,
ROHIT

2 Likes

Hi ROHIT, @ROHIT_SR

I think there is very much room left for interpretation of that document.

If I were trying to have my halo approved by the committee, I would want to know specifically, the rigidity of the test structure that the test halo would be mounted to in order to measure the required deflection of the halo under load.

The document does not specify that.

I do believe that they intend the rear joint to be rigidly fixed in all degrees of freedom to the vehicle.

However, I think that the front joint described in 3.5 is a pinned joint on the test fixture (if that is the actual test fixture that they have shown us in the document and which is used for approval testing).

  • 3.5 Front Fixing Axis
    The cylindrical joint connecting the Central Pylon
    to the Front Bracket.

I think that sometimes specification documents fail to fully specify what is intended :wink:

Dale

2 Likes

HI @DaleKramer sir,
you are right. there is info in detail about this project. only 3 company in the have permission to manufacture this f1 halo.

so, FINALLY, can I used pinned joint or fixed join for this project? @rszoeke @jousefm @DaleKramer @BenLewis
if it’s pinned THAN I will change the results image in this post.

THANK YOU
ROHIT.

With all the supplied info, I personally would use a pinned point…

1 Like

But how is he gonna decide the dimension of the hole :thinking:? Its not mentioned in the pdf

OK SIR ,
I WILL CHANGE THE RESULTS
i am waiting for other thought also.
thank you,
rohit

Call the people who test it, or take a few guesses and see how the diameter affects results ???

According to me, there is no need to give a pin joint as if you closely look at the front end of the halo, you will realize that the contour on the halo’s surface fit perfectly into the clamping surface(like soul mates :rofl:) thus restricting all the 6 DOFs. So I don’t think that there will be a drastic affect of changing the current configuration and assigning new constraints.

4 Likes