First, we must calculate the force acting on each A-Arm before designing the A-Arm. There are three types of force acting on the A-Arm: Vertical force (Bumping force), Lateral force (Cornering force), and Longitudinal force (Acceleration and Braking). Each parameter has its dynamic load factor. Each dynamic load factor value is based on a paper from Perlis University Malaysia, which calculated various forces in the suspension system. The dynamic load factor is determined as follows.

• Vertical dynamic load factor:   2.5G

• Lateral dynamic load factor:   2.0G   (Design spec average 1.6G)

• Longitudinal dynamic load factor:   1.5G   (Design spec average 1.1G)

vehicle parameter

Vertical force (bumping force)

From a vertical dynamic load factor of 2.5G, we can derive the following:

• Maximum instantaneous dynamic front wheel load = 1240 x 2.5 = 3100 N

• Maximum instantaneous dynamic rear wheel load = 1550 x 2.5 = 3875 N

Lateral force (cornering force)

From a lateral dynamic load factor of 2.0G, we can derive the following:

• Maximum instantaneous dynamic front axle load = 3100 x 0.4 x 2.0 = 2480 N

• Maximum instantaneous dynamic rear axle load = 3100 x 0.6 x 2.0 = 3720 N

longitudinal force (acceleration & Braking)

From a longitudinal dynamic load factor of 1.5G, we can derive the following:

• Maximum instantaneous braking force = 3100 x 1.5 = 4650 N

• Maximum instantaneous acceleration force = 3100 x 1.5 = 4650 N

• C.G. position distance from front axle (b) = 0.6 x 1560 = 936 mm

• C.G. position distance from rear axle (b) = 0.4 x 1560 = 624 mm

force summary table