###### Abstract  
Numerical simulations have the potential to be used for designing damage-tolerance composite structures. However, numerical models are currently computationally intensive, and their post-failure evolution and fracture morphology predictions are still limited. In the present work, a numerical methodology to simulate advanced composite joints is presented. The results of a numerical campaign aimed to evaluate the progressive damage and failure analysis (PDFA) of an advanced pin-hole connection under tensile and compressive load are evaluated. A high-fidelity stacked shell-cohesive methodology is employed to simulate the ultimate load, fracture initiation, and propagation of the proposed composite joint. Post-failure erosion methodology is proposed to control the initiation and evolution of composite fractures. The location and extension of the numerically predicted damages are compared with experimental observations. The proposed methodology demonstrates its preliminary ability to be used for designing composite joints up to failure. Specific outcomes are also pointed out. fracture mechanics; delamination; cohesive elements; LS-DYNA; advanced joint +
Footnote †: journal: Medical and Aerospace Engineering  
**Citation:** [PERSON]; [PERSON] [PERSON]. ;  
[PERSON]; [PERSON]; [PERSON] A Structured Methodology to Simulate Composite Advanced Joint Behavior for Ultra-Light Platforms  
**Accepted:** 8 January 2023  
**Published:** 11 January 2023  
any permanent effects on the materials; (c) easy and correct positioning of the different structural parts demonstrating the right clearance and tolerance limit. Stress distribution around holes in anisotropic composite plates subjected to specific loading combinations is well understood; e.g., [5; 6]. However, damage in a composite joint can initiate at an early stage and accumulate inside the laminate as the load increases. Different failure modes depend on the choice of material, ply stacking sequence, laminate thickness, joint geometry, edge effects, and bearing and clamping effect, all based on the applied loading conditions. The validation and verification of the structural sizing of such composite joints is carried out using a combination of experimental tests and static numerical analysis. Nevertheless, the evaluation of failure and post-failure modes is frequently excluded from numerical studies. Typically, designers tend to increase experimental investigations to reconstruct the failure modes of a composite structure according to normative [7]. The lack of a fully validated and standardized numerical tool has become fundamental in the preliminary design procedure, especially for the design of composite structures subjected to specific critical loads. These tools are requested to accurately and reliably predict physical response when damage is initiated and failure mechanisms start, as described in [6; 7; 8; 9; 10]. Referring to the experimental activities described in [PERSON] et al. [2] at Politecnico di Torino under the \"HELINET\" project, a structured comparison between the numerical results and the experimental observations is proposed here. The experimental joint configuration is based on a solid or sandwich CFRP laminate with the same lay-up loaded in two different structural configurations: (a) basic laminate joint, (b) innovative joint configuration (\"advanced joint\" in the following) completed with a steel reinforcement at the hole position specifically designed to overcome the bearing failure mode of a composite laminate (see Figure 1). High-fidelity new shell-cohesive progressive damage failure analysis (PDFA) methods, different with respect to the solid-cohesive one as reported in the open literature and described in Section 3, have been proposed to numerically reconstruct the performances of specified sandwich sample structural configurations under tensile and compression loading conditions. A complete stacked shell modeling technique, as described in [PERSON] et al.