How to Calculate forces coming on Knuckle

Steering knuckle is the most stress sustaining and critical component of All Terrain Vehicle (ATV). Steering knuckle is the pivot point of the steering and suspension system, which allows the front wheels to turn and also allow the movement of suspension arms motion. The light weight and high strength component is always in demanding for racecar application.
Lightweight and optimized design of steering knuckle is proposed to use for a BAJA SAE INDIA off road racecar. Due to the failure in knuckle in terrain vehicle after some instances, it has to be modified for better performance. The 3D CAD model created by using CATIA V5 and static as well as model analysis carried out in ANSYS 12 to understand its behavior under operating conditions. All test for frame was carried out on aluminum alloys 6061-T6 & for spindle EN8. The paper discusses the FE analysis of existing and modified Steering Knuckle.

Calculation of Load:

Axial Loads
The two major loads acting on the knuckle are Tensile and
Compressive loads. The stresses due to these loads can be
determined using the following formulas
Tensile Load (Pt) = Tensile Stress X Area
Compressive Load (Pc) = Compressive Stress X Area
Inertia Load
This load is due to the inertia of the moving parts. To calculate
the inertia force, first two harmonies are taken into
consideration. It is given by,