Rib Tread Sipe Depth Variation for Shear Strain Dispersion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic tires with rib patterns experience uneven wear and inferior wet performance, particularly in heavy-duty vehicles like trucks and buses, due to localized ground contact pressure and reduced grip on wet surfaces.
Innovation Solution
The tire features a tread surface with circumferential grooves and ribs that include a continuous circumferential sipe and widthwise sipes, with varying depths to disperse shear strain and enhance grip, reducing uneven wear and improving wet performance by moderating ground contact pressure and providing longer edge distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rib patterns are used for heavy duty vehicles traveling at high speed, then productivity is improved, but the end portions of ribs experience greater shear strain leading to uneven wear
Solution Approach 1:
The rib structure is divided into multiple segments by circumferential sipes extending continuously in the circumferential direction and widthwise sipes disposed at prescribed intervals. This segmentation allows shear strain to be distributed across multiple smaller units rather than concentrated at the rib ends, enabling high-speed travel while preventing uneven wear
Solution Approach 2:
The sipe depth is optimized for different rib regions: depthwise sipes in the end regions are deeper to specifically address the high shear strain at rib ends, while widthwise sipes in the middle regions are shallower. This localized quality differentiation protects against uneven wear at critical areas while maintaining overall rib performance at high speeds
2Reliability
If the depth of widthwise sipes is increased in the center region and end regions, then shear strain dispersion is improved and uneven wear is reduced, but manufacturing complexity increases
Solution Approach 1:
The widthwise sipes are designed with depth variations tailored to specific rib regions: deeper in the center and end regions where shear strain is highest, and shallower in the middle regions. This localized quality approach optimizes wear resistance at critical areas while minimizing overall manufacturing complexity compared to uniformly deep sipes throughout
Data Source
AI summary
A circumferential sipe extends continuously in the circumferential direction of the tire in the center region of the tread surface section of a rib defined between circumferential grooves. Widthwise sipes are disposed at prescribed intervals in the circumferential direction of the tire in the tread surface section, the widthwise sipes extending in the widthwise direction of the tire in crossing relationship to the circumferential sipe, the widthwise sipes each having opposing terminal ends open to the circumferential grooves. The circumferential sipe changes in depth periodically in such a manner that the circumferential sipe is shallow between adjacent widthwise sipes. The widthwise sipes changes in depth in such a manner that they are greater in depth in the center region and end regions of the tread surface section.