Numerical investigation of stringer-frame intersections for stitched aerospace structures

In recent years, the aviation industry has taken a leading role in the integration of composite structures in an effort to develop lighter and more fuel efficient aircraft. Among the leading concepts to achieve this goal is the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept. The highly integrated structure of PRSEUS allows pressurized, non-circular fuselage designs to be implemented, enabling the feasibility of Hybrid Wing Body (HWB) aircraft. In addition to its unique fabrication process, the through-thickness stitching utilized by PRSEUS overcomes the low post-damage strength present in typical composites. The focus of most studies in the literature has focused on developing a HWB structure, with only a few discussing the application of PRSEUS to a tube-wing fuselage structure. Additionally, the majority of investigation for PRSEUS has been performed experimentally. The current work presents a numerical investigation of the stringer-frame intersection for both HWB and tube-wing fuselage concepts using a high-fidelity mesoscale approach. The results are compared with existing component level experiments and numerical results from literature. By significantly improving upon the existing capability for stitched composite damage prediction, the presented work allows detailed insight and understanding of stitched aerospace structures.