Enhancing stress distribution in force sensors by optimizing relief hole placement

Accurate and reliable force measurement is critical in fields such as industrial automation and robotics. The performance of a force sensor is fundamentally linked to the stress distribution uniformity within its force-measuring structure. To address the issue of measurement inaccuracy caused by stress concentration in conventional sensors, this study introduces an innovative design that incorporates relief holes to optimize stress distribution. Using finite element analysis, this research systematically investigates the influence of varying the distance (d) of the relief holes from the structural center (d=14, 16, and 18 mm) on stress homogeneity. The degree of optimization was quantitatively assessed using defined absolute and relative non-uniformity indices. The results demonstrate that the configuration with d=16 mm yields the most significant improvement, reducing the relative stress non-uniformity in the near-center region to 65.3% of the original design under a 5000 N load, while maintaining minimal impact on the stress distribution in the near-edge region. This work provides a novel and validated strategy for enhancing force sensor performance through structural optimization.