PSI - Issue 77

Francisco Castro et al. / Procedia Structural Integrity 77 (2026) 611–630 Francisco Castro/ Structural Integrity Procedia 00 (2026) 000 – 000

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Figure 2 – Vehicle roll dynamics model (y-z cross section).

The suspension stiffness of each side of the vehicle which involves the superposition of front and rear springs in serial association with the tires’ stiffness is given by, = + (12) The focus now is on the evaluation of the vehicle roll moment due to the suspension elasticity (assuming that the spring characteristics, e.g., force/displacement represents a linear behavior). Considering that the vehicle rotates around its longitudinal principal inertia axis, passing through the centre of mass, if there are only horizontal forces acting along the transverse direction of the vehicle run, then it is physically realistic to expect the vehicle rotation about the longitudinal axis. Additionally, it is important to note that there is no additional displacement along the vehicle’s vertical direction at that principal axis of inertia. Considering point G as a centre of rotation, the distance from G to the spring line (of both sides of the vehicle) is 2 . Then, for a roll angle (as shown in the Figure 2) from one side, the suspension force is, _ = × × ( ⏟ 2) , (13) The corresponding moment due to force referred to point G is, 1 = × × ( 2 )×( 2 ) 1 = × × ( 2 ) 2 (14) The vehicle’s roll torque is the superposition of both moments described, one referring to the spring compression while the opposite side refers to the spring extension, =2×( × × 2 4 )