FB Misuse
Among load cases concerning vehicle suspension strength and durability, the misuse case is very special because of large obstacles. In normal rolling conditions, contact occurs between tire and road surface. To handle misuse deformations, the contact between the inner surface of the tire and the rim has to be dealt with. The model can be used together with mbs full vehicle models. One example is the determination of the critical test velocity, which generates the maximum of suspension stresses and can be found using RMOD-K 7.
Major obstacles:
- cleat (height 80 [mm])
- pothole (depth 120 [mm])
test vehicle (18 canals) with mounted complete passenger car rear axle
Contact algorithm extend to inner contact between tyre and rim.
boundary condition 1: no major effect on computational effort
boundary condition 2: small number of new parameters
model containing nonlinear unilateral stiffness elements
- gap data generate from cross section information (picture in the middle)
- principal drawing of contact elements at large tyre displacements (picture on the right)
- cleat dimension in the range of the tyre sidewall height (picture on the left)
- different rim stiffness left/right result in torque Mx
- inner contact starting at 78 [mm] displacement
- torque Mx will load suspension elements by 700 [Nm]
Test vehicle before cleat crossing:
- vehicle model in ADAMS/CAR
- rear axle tyres: RMOD-K 7 FB
- front axle tyres: MF
- nonlinear mbs elements (damper, bumps,…)
