Design and analysis of mounting and pullout of auxetic dowel fasteners under quasi-static loadings

Abstract Fasteners are used in various industries to join two components mechanically or to fix an object and prevent its movement due to impact, pressure, vibration, or thermal effects. This research investigates the negative Poisson’s ratio auxetic lattice structure in polyamide 12 (PA12) dowel pins with standard geometries, with the objective of designing an optimized lightweight, non-permanent fastener that minimizes mounting force while maximizing grip strength, ensuring no damage or failure occurs to the pin during the pullout process. The pin geometries in solid and hollow configurations, together with the effects of cell number and size, cell rotation, and the combination of two auxetic cell types, were analyzed. Auxetic cells were incorporated into the pin’s cylindrical structure by defining a two-dimensional cell pattern in the cylinder’s cross-section and subsequently applying axially symmetric rotation. Quasi-static simulations were performed to model both the mounting and pullout processes for all dowel pin designs. Additionally, a dedicated simulation model was developed for each geometry to determine its Poisson’s ratio. The top-performing models from each group were selected based on their superior functional characteristics, with results presented alongside corresponding Poisson’s ratios. The findings demonstrate that hybrid auxetic structures can significantly enhance fastener performance when structural weight is a critical design constraint.