Mechanical properties of porous 3D-printed polycaprolactone: Experimental and numerical study

This study presents a systematic investigation into the porosity-strength relationships of 3D-printed polycaprolactone (PCL) to develop predictive models for the tensile behavior of porous structures intended for biomedical applications. The research investigates the impact of void geometry and porosity levels on the mechanical response under uniaxial tensile loading, utilizing Finite Element Method (FEM) simulations and Scanning Electron Microscopy (SEM) to elucidate stress distribution, plastic deformation, and fracture mechanisms. Three void geometries-circular, square, and triangular-were analyzed across porosity levels ranging from 6 % to 30 %. Circular voids demonstrated superior stress uniformity and deformation homogeneity, while square and triangular voids exhibited localized stress concentrations and earlier onset of plasticity. Increasing porosity resulted in a marked reduction in yield stress, with maximum decreases of 24 % in square voids, 23 % in triangular voids, and 15 % in circular voids. SEM analysis revealed manufacturing defects that significantly influenced deformation behavior. The adopted Elastic-Plastic numerical model showed strong agreement with experimental observations in terms of yielding force and ultimate force, presenting an error of less than 10 %. A statistical model was developed, achieving R-squared values exceeding 0.95, which enabled the reliable estimation of tensile properties within the studied porosity range. These findings offer critical insights into the mechanical optimization of porous PCL scaffolds, providing a robust framework for future design strategies in biomedical engineering.