Degradation Modelling and Mechanical Performance of Bio-Based Composites (Materials Engineering) VILNIUS TECH

Overview

Bio-based polymer composites are increasingly used in engineering and consumer applications due to their sustainability potential. However, wider application is limited by insufficiently predictable performance under environmental exposure. Degradation processes such as moisture- and temperature-driven ageing, UV-induced changes, and end-of-life biodegradation conditions can lead to time-dependent loss of mechanical performance. Predictive models linking exposure regimes to mechanical property evolution remain insufficient, particularly for additively manufactured materials whose microstructure and anisotropy depend strongly on processing conditions.This doctoral research will develop an experimentally validated modelling framework for predicting and, where needed, controlling degradation-driven changes in mechanical performance of bio-based composite systems, with a focus on PLA-based formulations. Additive manufacturing (primarily FDM/FFF) will be used as the main fabrication route to produce specimens with controlled geometry and processing parameters, while material formulations will be systematically modified using selected additives and modifiers.The work will integrate environmental ageing experiments, mechanical characterization, and analytical and numerical modelling to establish quantitative relationships between exposure conditions, material formulation, manufacturing parameters, and resulting changes in stiffness, strength, and energy absorption capacity. The main idea is that the service life of bio-based composites can be predicted, and in part controlled, by describing how environmental ageing changes their mechanical properties over time. The scientific novelty of the project is the development of a predictive model that links degradation processes to measurable mechanical performance in additively manufactured materials, and its validation under different exposure scenarios, including both long-term ageing conditions and end-of-life/composting environments.