Tire Tread Band Lining Structure for Fatigue Resistance
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Solution Overview
Problem
Heavy-load vehicle tires suffer from premature decay due to uneven stress distribution and fatigue in the tread band, leading to anomalies, cracks, and reduced lifespan, particularly in the groove bottom area where stress concentration and localized temperature increases occur.
Innovation Solution
A tire design featuring a tread band with a lining structure comprising at least two radially overlapped layers with decreasing elastic moduli, providing a gradual decrement in elastic modulus from the tread band to the outermost layer to better distribute stress and strain, thereby enhancing fatigue resistance and preventing premature anomalies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a single-layer lining structure with uniform elastic modulus is used, then the manufacturing process is simple, but the stress distribution remains uneven and fatigue resistance is insufficient
Solution Approach 1:
The lining structure is divided into multiple layers with different elastic moduli. The first lining layer has a first elastic modulus and the second lining layer has a second elastic modulus that is lower than the first, creating a gradient structure that progressively distributes stress from the tread band outward, reducing stress concentration at the groove bottom while maintaining manufacturing feasibility through layered construction
Solution Approach 2:
The patent employs composite material construction by combining elastomeric materials with different elastic moduli in a layered configuration. This composite approach allows the lining structure to simultaneously provide stress distribution benefits of lower modulus materials and structural support of higher modulus materials, enhancing overall fatigue resistance without excessive complexity
2Stress or pressure
If the elastic modulus of the lining structure is uniformly low, then stress distribution improves, but the structural support and shape maintenance capability deteriorates
Solution Approach 1:
Different regions of the lining structure are assigned different elastic moduli to perform different functions. The first lining layer with higher elastic modulus provides structural support and shape maintenance near the tread band, while the second lining layer with lower elastic modulus provides stress distribution and fatigue resistance at the outer region, optimizing both structural support and stress distribution locally
Solution Approach 2:
The elastic modulus parameter is varied across the lining structure layers. By changing the elastic modulus from the first layer to the second layer, the patent creates a gradient that allows the structure to simultaneously achieve good stress distribution (lower modulus) and structural support (higher modulus) in different regions, resolving the contradiction between these two requirements
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces the occurrence of cracks and tears in the tread band, extending the tire's lifespan and maintaining performance by distributing stress more evenly across the elastomeric material, thus improving ride comfort and handling.
Implementation Method 1
providing a gradual decrement in elastic modulus from the tread band to the outermost layer to better distribute stress and strain
Implementation Method 2
said lining structure comprises at least one radially internal layer superimposed on the tread and having a second elastic modulus and at least one radially external layer having a third elastic modulus, lower than that of the second elastic modulus
Implementation Method 3
Generation of cyclically repeated strain and stresses due to the tread entering and exiting the footprint area, can cause arising of cracks and torn portions on the groove bottom, as well as localised temperature increases and phenomena of fatigue of the elastomeric material
Implementation Method 4
decreasing elastic moduli in direction radially away from the tread band, allowing for a better distribution of stress and strain and accordingly for a better dumping thereof inside the elastomeric materials
Data Source
Figure 1
Figure 2
AI summary
A tire for vehicle wheels comprises a tread band including a first elastomeric material having a first elastic modulus (Et) and comprising a plurality of circumferential grooves formed in said tread band, each of said circumferential grooves being defined by a couple of lateral walls separated by a bottom, at least one of said grooves including a lining structure superimposed on the tread band in at least the groove bottom, said lining structure comprises, at least one radially internal layer superimposed on the tread and having a second elastic modulus (E2) and at least one external layer joined to the internal layer and having a third elastic modulus (E3), lower than that of the second elastic modulus (E2).