Issue 59

M. Shariyat, Frattura ed Integrità Strutturale, 59 (2022) 423-443; DOI: 10.3221/IGF-ESIS.59.28

histories shown in Fig. 4. The time histories of the stress components have to be processed based on the proposed criteria to determine the critical elements which specify the fatigue life of the whole chassis frame. Some of the resulting stress analysis results [the equivalent stresses defined in Eqn. (27)] are depicted in Fig. 8.

Item

Quantity 2650 kg

GVW (Gross vehicle weight)

Front axle mass Rear-axle mass

95 kg 125 kg

The front suspension stiffness

60200 N/m 11600 Ns/m 74000 N/m 1105 Ns/m 402 kgm 2 4308 kgm 2

The front suspension damping coefficient

The rear suspension stiffness

The rear suspension damping coefficient Vehicle’s roll moment of the inertia Vehicle’s pith moment of the inertia Vehicle’s yaw moment of the inertia

3260 kgm 2 Table 4: Some of the dynamic parameters of the full vehicle finite element model.

(a)

(b) Figure 8: Typical contours of the  eq equivalent stress [Eqn. (27)] of the: (a) E-Glass/Epoxy and (b) Carbon/Epoxy chassis frames. The most critical elements are shown in Fig. 8 and are located in a region ahead of the front mount of the rear leaf spring of the chassis. The obtained fatigue lives in terms of kilometers of traveling are reported in Tab. 5, for the main fatigue

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