Development of Design Guidelines for Thermoplastic Welded Joints in Aerospace Applications - a Holistic Approach from Process Technology to Simulation
Topic(s) : Industrial applications
Co-authors :
Sebastian HAMEDINGER (AUSTRIA), Markus JUR , Roland HINTERHÖLZL (AUSTRIA), Stephan BECKER (AUSTRIA), Gernot WALLNER , Rene ADAM (AUSTRIA)Abstract :
With upcoming urban air mobility and increasing space missions, aerospace industry is about to take the next evolutionary milestone after the introduction of civil aviation. With skyrocketing numbers of urban air flight vehicles the next decades, special requirements on material and processability are required to satisfy the demand on light weight, high performance aircraft components. Thermoplastic composites not only captivate with excellent mechanical and chemical properties, they also provide recyclability in order to fulfil the sustainable development goals. Additionally, thermoplastic composites come with beneficial attributes in processing and insist high weight saving potential with the application of thermoplastic welding.
This joining technique implies a reduction of weight, machining and assembling efforts, as well as stress concentrations by rendering classical used rivet joints as omittable. Furthermore, thermoplastic welded joints offer a sealed connection between two adherend components, including high automation potential of the welding process to be prepared for high serial production.
This research utilizes a holistic approach generating validated design guidelines for aerospace stress and design engineers, including an investigation and parameter study for various thermoplastic welding technologies (Figure 1), a simulation-based multiscale study (Figure 2), as well as an experimental study from coupon to the sub-element level (Figure 2). These integrated guidelines ease the application of thermoplastic welded joints, as well reducing the development, testing and qualification efforts to enable a quick time to market.
Earlier performed studies mainly focused on the influence of single parameters like the adherend and adhesive thickness or the layup. A general approach, providing validated design guidelines, considering the main parameters responsible for the welding performance, have not been found jet. To screen important process and design parameter, test plans following the design of experiments, have been created and the needed test specimens have been produced with the respective thermoplastic welding processes. Additional several analysis methods have been investigated and rated according to applicability for the full-scale part development, performance and accuracy. Further, the test campaign is evaluated, material parameters are transferred to simulation, which then gets validated by tests on the sub-component level. Besides the welding strength, special attention is brought to damage and fracture behavior to gain an in depth understanding of the mechanics of the welded joint. Finally, all the found influences are collated in design guidelines for thermoplastic welded joints.
This joining technique implies a reduction of weight, machining and assembling efforts, as well as stress concentrations by rendering classical used rivet joints as omittable. Furthermore, thermoplastic welded joints offer a sealed connection between two adherend components, including high automation potential of the welding process to be prepared for high serial production.
This research utilizes a holistic approach generating validated design guidelines for aerospace stress and design engineers, including an investigation and parameter study for various thermoplastic welding technologies (Figure 1), a simulation-based multiscale study (Figure 2), as well as an experimental study from coupon to the sub-element level (Figure 2). These integrated guidelines ease the application of thermoplastic welded joints, as well reducing the development, testing and qualification efforts to enable a quick time to market.
Earlier performed studies mainly focused on the influence of single parameters like the adherend and adhesive thickness or the layup. A general approach, providing validated design guidelines, considering the main parameters responsible for the welding performance, have not been found jet. To screen important process and design parameter, test plans following the design of experiments, have been created and the needed test specimens have been produced with the respective thermoplastic welding processes. Additional several analysis methods have been investigated and rated according to applicability for the full-scale part development, performance and accuracy. Further, the test campaign is evaluated, material parameters are transferred to simulation, which then gets validated by tests on the sub-component level. Besides the welding strength, special attention is brought to damage and fracture behavior to gain an in depth understanding of the mechanics of the welded joint. Finally, all the found influences are collated in design guidelines for thermoplastic welded joints.