- #1

- 1

- 0

## Main Question or Discussion Point

I have to do some dataacquisition from a car with some accelerometers.

4 accelerometers is placed on the wheels before the shock absorber. And i need to calculate the maximum applied G-force on the accelerometers.

Just an approximately value, not taking in account the type of wheel, airpressure in wheel etc.

Scenario 1:

Steady speed of the car driving on normal tarmac is 110km/h.

Weight of car is 2000kg

The car is driving over a small bump with a height of 5cm

Scenario 2:

Steady speed is 50km/h

Weight 2000kg

The car is driving over a regular speedbump, approximately height of 30cm

Seeing the bump on the wheel as if was a regular spring, i would calculate acceleration from

A=5cm

ω=sqrt(k/m) (not knowing the spring constant, i just took some samples from 0-500Hz as a value, whats realistic here?)

a=-ω^2*A*cos(ω*t)

with a.max being -ω^2*A

and then divide final max acceleration with 9.8m/s^2. But this seem to give me abnorm large value of g-force.

Any help, to how to calculate this the right way?

4 accelerometers is placed on the wheels before the shock absorber. And i need to calculate the maximum applied G-force on the accelerometers.

Just an approximately value, not taking in account the type of wheel, airpressure in wheel etc.

Scenario 1:

Steady speed of the car driving on normal tarmac is 110km/h.

Weight of car is 2000kg

The car is driving over a small bump with a height of 5cm

Scenario 2:

Steady speed is 50km/h

Weight 2000kg

The car is driving over a regular speedbump, approximately height of 30cm

Seeing the bump on the wheel as if was a regular spring, i would calculate acceleration from

A=5cm

ω=sqrt(k/m) (not knowing the spring constant, i just took some samples from 0-500Hz as a value, whats realistic here?)

a=-ω^2*A*cos(ω*t)

with a.max being -ω^2*A

and then divide final max acceleration with 9.8m/s^2. But this seem to give me abnorm large value of g-force.

Any help, to how to calculate this the right way?