Heavy Goods Vehicle Tyre Reinforcement for Fatigue Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tires with metal carcass reinforcement in heavy goods vehicles experience fatigue and 'zipper failure' due to cyclic bending stresses, especially when partially or totally deflated, leading to potential bursting and overpressure waves upon reinflation.
Innovation Solution
Incorporating a radial carcass reinforcement with additional textile reinforcements oriented at specific angles and a second reinforcement structure featuring alternating parts of different breaking strengths to limit deformation and rupture propagation, reducing the circumferential length of the opening and mitigating the blast effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the tire uses metal carcass reinforcement to resist internal inflation pressure, then the strength and load-bearing capacity are improved, but the metal reinforcements are subjected to cyclic bending stresses that cause fatigue and zipper failure
Solution Approach 1:
The patent combines metal carcass reinforcements with textile reinforcements (aramid, polyester, or polyamide) to create a composite structure. The textile reinforcements are arranged at angles of 80-90 degrees to the circumferential direction, providing resistance to cyclic bending stresses while the metal reinforcements maintain structural strength and pressure resistance. This composite approach allows the textile layer to absorb bending fatigue while the metal layer provides overall structural integrity.
2Adaptability or versatility
If the tire operates with partial or total deflation, then adaptability to severe driving conditions is improved, but the amplitude of curvature variations increases causing amplified bending stresses on the carcass reinforcement
Solution Approach 1:
The composite structure of metal and textile reinforcements works particularly effectively under deflated conditions. When the tire is partially or totally deflated, the textile reinforcements absorb the amplified bending stresses that occur due to increased curvature variations, protecting the metal reinforcements from fatigue damage while maintaining the tire's adaptability to severe driving conditions.
3Reliability
If the carcass reinforcement suffers fatigue from metal reinforcements, then resistance to rupture under tension decreases, but adding more metal reinforcement increases the harmful overpressure wave upon bursting
Solution Approach 1:
The textile reinforcements (aramid, polyester, or polyamide) arranged at 80-90 degrees to the circumferential direction provide additional resistance to rupture under tension without significantly increasing the overpressure wave upon bursting. The textile materials have different failure characteristics compared to metal, allowing energy absorption that reduces the harmful blast effect while maintaining structural integrity.
Data Source
Figure 1~2
Figure 3~5
AI summary
Tyre (10) comprising a radial carcass reinforcement (2) anchored in beads, the tyre (10) comprising two sidewalls (1), each sidewall (1) extending between a bead (4) and a crown (3), the two sidewalls comprising a first additional reinforcement (6) positioned either between the carcass reinforcement and the internal cavity of the tyre or axially on the outside of the carcass reinforcement, and at least one of the sidewalls comprising a second additional reinforcing reinforcement (5), this tyre being characterized in that the first additional reinforcement comprises a plurality of reinforcing elements of a textile nature directed at an angle of at least 80 degrees and at most 90 degrees with respect to the circumferential direction, and in that the second additional reinforcement (5) comprises, in the circumferential direction and alternating, a plurality of first parts (51) and of second parts (52), these second parts (52) having a mean width at least equal to 20 mm, these first and second parts having rupture strengths, that is to say rupture forces per unit width of reinforcement, which are such that the rupture strength of the second parts (52) is lower than the rupture strength of the first parts, and in that the first and second additional reinforcements are positioned on either side of the carcass reinforcement.