This study evaluates the environmental impacts of shipbuilding materials through life cycle assessment (LCA) and assesses potential exposure under the EU Carbon Border Adjustment Mechanism (CBAM). Three representative vessel types, a pure car and truck carrier (PCTC), a bulk carrier, and a container ship, were analyzed across scenarios reflecting different steelmaking routes, recycling rates, and regional energy mixes. Results show that structural steel (AH36, EH36, DH36, A/B grades) overwhelmingly dominates embedded emissions, while aluminium and copper contribute secondarily but with high sensitivity to recycling and energy pathways. Coatings, polymers, and yard processes add smaller but non-negligible effects. Scenario-based CBAM cost estimates for 2026–2030 indicate rising liabilities, with container vessels facing the highest exposure, followed by bulk carriers and PCTCs. The findings highlight the strategic importance of steel sourcing, recycling strategies, and verifiable supply chain data for reducing embedded emissions and mitigating financial risks. While operational emissions still dominate the life cycle, the relative importance of construction-phase emissions will grow as shipping decarbonizes. Current EU-level discussions on extending CBAM to maritime services, together with recognition of domestic carbon pricing as a potential pathway to reduce liabilities, underscore regulatory uncertainty and emphasize the need for harmonized methods, transparent datasets, and digital integration to support decarbonization.

The orientation of carbon fibers significantly affects the dynamic properties of unidirectional carbon-based composites (UCBCs), with variations under different static loads. A previous study analyzed changes in the modal parameters of UCBC structures by using the static load influential factor (SLIF). This study introduces a revised SLIF, derived from a simplified formulation that accounts for shifts in resonance frequency and the in-phase relationship between static load and modal response. The revised SLIF is theoretically linked to the modal participation factor in UCBC structures. The dynamic behavior of UCBCs was studied across six modes—four bending and two torsional—using specimens with five carbon fiber orientations, from 0 to 90 degrees. The revised SLIF showed significant effects in two robust specimens, #1 and #2, and an isotropic SUS304 specimen subjected to uniaxial pre-static load, with resonance frequency variations under 0.16%. In contrast, the original SLIF gave negligible results in the fifth mode due to a damping term, which, when multiplied by the resonance frequency, led to an undetectable indicator. Therefore, the revised SLIF more effectively captures the static load’s impact on UCBC dynamic behavior compared with the original method.