Drafting Apron Contact Dynamics

This paper presents a detailed study of contact dynamics in drafting apron systems used in textile machinery. Using Hertzian contact theory, we derive the contact half-width, contact area, friction force, resistive torque, and energy loss for four surface configurations. A correction factor fₐ accounts for surface-texture effects on effective contact length. Sensitivity analysis (OAT) identifies friction coefficient μ and normal load P as the dominant design variables, while Monte Carlo simulation (N = 5,000) yields CV = 15.9% and a 90% torque interval of [0.125, 0.210] mN·m.