DESIGN AND MODELING OF A DISCRETE VARIABLE STIFFNESSCOMPLIANT LINK AND ITS INTEGRATION WITH FOUR-BAR MECHANISMS FOR MULTIPLE OUTPUT TRAJECTORIES

The study investigated an innovative design and modeling approach for a compliant four-bar mechanism incorporating a variable stiffness link (VSL), which enabled multiple end-effector trajectories without requiring structural modifications. Conventional four-bar mechanisms have limited adaptability due to fixed configurations, constraining their applications in environments demanding flexible motion paths. The integrated VSL, serving as the output link, permitted trajectory versatility under consistent load conditions by allowing stiffness adjustments. The research involved analyzing both single-beam and multi-sectional configurations of the VSL, utilizing a large deflection model (LDM) and a pseudo-rigid-body model (PRBM) to simulate compliant behavior accurately. Comprehensive validation of the theoretical model included numerical simulations, finite element analysis (FEA), and physical testing with a 3D-printed prototype. Findings demonstrated that VSL significantly broadened the application potential of four-bar mechanisms, offering enhanced adaptability, efficient performance, and resilience across dynamic environments. The study contributed to the advancement of compliant mechanism design, providing valuable insights for applications in robotics, automotive systems, and biomedical devices where adaptable trajectories improve functionality and durability.