Experimental and Numerical Study of Failure Characteristics of Aircraft U-shaped Riveted Components Under Different Loading Angles

The failure of connecting components is one of the primary failure forms for transport aircraft under impact loads. For U-shaped riveted components, the failure characteristics under different loading angles (pure pull, 30°, 45°, 60°, and 90° pure shear) are studied using test and simulation methods, and the influence of varying thicknesses of U-shaped riveted components and loading angles on the failure characteristics is revealed. Bilinear element models (beam element, hexahedron element, 4–hexahedron cluster element, and 8–hexahedron cluster element) based on peak load failure are established. The SPR2 constraint element model is also developed, and a numerical model of rivets is obtained, which can be applied to aircraft crashworthy simulation. The results indicated that the rivet pull-out load transitions to the rivet shear load with increasing loading angles, and the rivet head pull-out failure changes to rivet rod shear failure. The out-of-plane tensile load of U-shaped riveted components changes to in-plane compressive load, and the failure displacement decreases. With increasing thickness of U-shaped components, the components become less susceptible to deformation, the failure load increases and the failure displacement decreases. Among the bilinear element models based on peak load failure, the failure loads and failure displacements obtained using the 8–hexahedron cluster element model exhibit the best agreement with test results. The deviation in failure load for the 8–hexahedron cluster element model and the SPR2 constraint element model is less than 10%; however, the deviation in failure load is smaller for the 8–hexahedron cluster element model. The deviation in failure displacement is slightly larger for the two models, but the deviation for the SPR2 constraint element model is within 15%. The 8–hexahedron cluster element model and the SPR2 constraint element model are suitable for aircraft crashworthy simulation applications.