Work

Ribbing without tooling: additive manufacturing of thermoplastic ribs on thermoset skins enabled by co-cured thermoplastic interphases

Year: 2026

Type: article

Abstract: This work evaluates tooling-reduced ribbing by printing thermoplastic stiffeners onto thermoset composite skins via co-cured, directly printable thermoplastic interphases. A helicopter door demonstrator provides the application context for localized reinforcement features in regions where SMC processing is constrained by limited flow and tooling-driven draft angles. Two material routes were investigated on M18/1 CFRP coupons as repeatable screening platforms. PEI served as a high-temperature reference interphase for printing PEI and PPSU, while PC was evaluated as a lower-temperature interphase for printing PETG. Differential scanning calorimetry was used to define substrate-temperature levels, and single-lap-shear tests provided first-order indicators of interface quality and process sensitivity. The results reveal a coupled thermal process window: insufficient activation leads to weak bonding, whereas excessive thermal exposure reduces lapshear strength despite successful deposition. An analytical model further quantifies the lightweighting potential of eliminating demolding draft angles, showing double-digit crosssectional mass savings for typical rib proportions.

Source: Advanced Manufacturing Polymer & Composites Science

DOI: 10.1080/20550340.2026.2689770

Authors: Matthias Taubert, Richard Welker, Bruno Musil, Philipp Höfer

Institutions: Universität der Bundeswehr München, Wehrwissenschaftliches Institut für Werk- und Betriebsstoffe

Language: English

Topic: Additive Manufacturing and 3D Printing Technologies

Subfield: Automotive Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $1,060