A Mechanical Performance Evaluation Framework for Adjustable Recliner Headrest Systems

Recliner headrest mechanisms are subjected to repeated mechanical loading that may cause excessive displacement, stress concentration in hinge regions, and fatigue degradation. Meanwhile, increased user demand for enhanced adjustability requires additional rotational freedom, often reducing structural stiffness. This study proposes a mechanical evaluation framework for recliner headrests integrating an additional ۱۵° of angular freedom while maintaining durability. Four quantitative criteria are defined: (i) maximum displacement under ۳۰۰ N load limited to ۱۰ mm, (ii) maximum von Mises stress limited to ۶۰% of yield strength, (iii) minimum fatigue life of ۱۰۰,۰۰۰ cycles, and (iv) functional angular enhancement. A simplified finite element model of the headrest arm and hinge assembly is developed. Static and high-cycle fatigue analyses are performed for baseline and modified configurations. Results show that although added adjustability increases displacement and stress levels targeted hinge reinforcement improves compliance with displacement, stress, and fatigue performance requirements. The proposed framework supports early-stage design decisions by linking functional enhancement with structural reliability.

کلیدواژه ها:

Recliner headrest ، fatigue life ، hinge reinforcement ، stress concentration ، finite element analysis