Experimental and numerical damage assessment of PLA based on young’s modulus reduction using the bonora damage model

The goal of this paper is to experimentally and numerically investigate damage evolution in PLA+ materials, based on the reduction of Young’s modulus during cyclic loading–unloading tests. Standard tensile specimens were fabricated via FDM 3D printing and tested under displacement-controlled cyclic loading, while strain was measured using both extensometer and digital image correlation. The Bonora damage model was calibrated for PLA+ by fitting the damage parameter to experimental plastic strain data. The obtained constants (Dcr=0.20, εth=0.012, εf=0.042, α=0.76) were implemented in a custom VUSDFLD subroutine in ABAQUS. The finite element simulations successfully predicted final failure, showing good agreement with the experimental damage parameter evolution. The numerical predictions deviated <5 % from experimental results, confirming the high accuracy of the Bonora-based model implementation. This combined experimental–numerical framework provides a reliable basis for predicting progressive damage in PLA+ components under quasi-static loading. The novelty of this work lies in the calibration of the Bonora model for PLA+, which shows enhanced ductility compared to conventional PLA, and in demonstrating its potential for reliable application in both engineering load-bearing structures and biodegradable biomedical devices.