ADAMS - Project - Hardpoint tuning to achieve pitch gradient targets using suspension “anti” characteristics

ANTI CHARACTERISTICS-

Anti-Geometry consists of anti-dive, anti-squat, anti-lift. Anti-geometry refers to the front and rear wheels that controls the amount of the travel in spring due to acceleration or braking conditions.

The anti-geometry doesn't alter the amount of longitudinal load transfer that occurs in braking or accelerating as the load transfer is function of wheel base, accelerating or braking force, height of CG.

What is squat?
When the car is accelerating, a longitudinal force is applied, due to the acceleration there is a load transfer in which the front wheel is lightly loaded and the rear wheel are heavily loaded. The front wheels will be in rebound and the rear wheel will be in compression.

What is dive?
When the car is deceleration or braking, a longitudinal force is applied, due to braking there is a load transfer in which the front wheel is heavily loaded and the rear wheels are lightly loaded. The front wheels will be in compression and the rear wheels will be in rebound.

The objective is to perform hardpoint tuning to achieve the target acceleration and braking pitch gradients.

The link for the excel sheet(manual calculations) is mention below-

https://docs.google.com/spreadsheets/d/1HWGllH2qrCps0q8zX5PJ1oGzBWsHRcSt0S-IAY1U9FM/edit?usp=sharing

Lets import both double wishbone suspension and rear multi link suspension for carrying out our Hardpoint tuning.

The inputs are given in the question to build front and rear suspension adams models.
so those values are used to for our suspension assembly, before performing parallel wheel travel.

Then parallel wheel travel simulation is run for both the assemblies, which is considered as the initial/ original values with no changes in hardpoints. and then after this hardpoints were changed accordingly several times to achieve the values.

After the hardpoints were changed, graphs were ploted for wheel travel vs ride rate for both Sla and multilink, And these new tuned hardpoint graphs are compared with initial/original values to compare the difference. The plots are mention below-

The hardpoints are modified again slightly, to find out the swing arm length and swing arm angle for both double wishbone suspension and rear multilink suspension.

The plot are mentioned below-

Hence by tuning the hardpoints the mention targets in the question are achieved..

Anti characteristics-

Braking-

front end anti dive=

Rear end anti lift=

ACCELERATION-

Front end anti lift=

Rear end anti squat-

All the values we get in the adams are mentioned in the excel sheet mentioned above.
Hence the target is achieved..