Experimental Evaluation and Predictive Modeling of Composite Material Crashworthiness.

The growing demand for safer, lighter, and more sustainable structures has accelerated the development and validation of composite materials, which offer exceptional combinations of strength and lightweight. This thesis, a collaboration between Politecnico Di Torino, ITW Test and Measurement Italia s.r.l. - Instron CEAST division and The Leibniz-Institut für Verbundwerkstoffe GmbH, investigates a novel testing methodology for assessing Specific Energy Absorption (SEA) and introduces predictive models to evaluate the influence of geometry on crashworthiness performance. Motivated by the lack of a universal standard for the assessment of the SEA, this study investigates the performance of six different composite materials (CF-PA6, CF-PA66, CF-PC, GF-PP, GF-TEPEX, and CF-Epoxy) were tested under dynamic loading using an Instron 9450 drop tower and high-speed imaging. The study systematically explores the effects of geometry, boundary conditions, and impact velocity on energy absorption, aiming to isolate the intrinsic crash performance of each material. Extensive data processing and statistical analyses identified the key parameters driving SEA variability, which were then integrated into predictive models capable of estimating the performance of corrugated geometries from flat coupon tests. Results show that geometry and velocity significantly affect crashworthiness, and that no universal predictive model applies across all composites—each material exhibits distinct behaviors. This work advances the experimental evaluation of composite crashworthiness by providing a reproducible methodology and predictive framework that support the design of lightweight, crashworthy structures for automotive, aerospace, and related applications.