The panel is one of the most important structural details of the aircraft and also is the main load-bearing component. The fatigue and damage tolerance performance of the detailed structure strengthened by panel is very important for the safety of aircraft

thus it is of practical significance to study the failure ofbolt connected beam-panel plates. In this paper

the fatigue of panel and beam connected structure was tested

and the crack propagation in the field of three-dimensional fatigue fracture is studied. Tests shown that initiation of cracks was randomness occurrence in rivet holes

also an interesting fact is that some of fatigue cracks only growth in panel plate

on the other side

some of the fatigue crack is propagation across through panel plate to beam plate.Analysis found that the mechanism of the crack growth from panelacross to beam plate was related to the crack or defects at the rivet hole side of beam that aroused from fatigue or machining. The 3D fatigue crack propagation model is established

and the 3D crack propagation in the structure from different initial siteswas calculated. It is found that the crack initiation at the bottom edge of the rivet hole has a slower propagation rate than that at up surface

the growth rate of the crack with initial deflection angle and torsion angle is also slower than that of crack with zero angles.