Damage Law Research Of2519A Aluminum Alloy Welding Joint

Welding is one of the main methods of2519A aluminum alloy’s shape. Thus,studying the damage discipline of welding joint has enjoyed considerableprominence on promoting the welding property and improving welding technology.On the basis of theory of failure, this paper carries out numerical simulation andexperiment by Ansys to research the impact of2519A aluminum alloy weldingjoint’s damage discipline through the situation that it contains hole, crack and theone including both hole and crack. The thesis researches from several aspects asfollows:1. This paper establishes the he finite element analysis model of hole in2519Aaluminum alloy welding joint and studied the influence of different shapes, sizes,locations of hole and the hole ligament width to stress concentration of welded joint2. The thesis verifies the simulation results by the tensile test sample of2519Aaluminum alloy welding joint including hole.3. The author researches the impact of different welding groove forms to thestress intensity factor and makes a compared analysis with the two-dimension modelon the condition that the author spreads center through cracks of welded joint from atwo-dimension model to the three-dimensional model of different welding grooveforms4. The writer studies the effect of the hole in welded joint to stress intensityfactor of crack tip and crack propagation path.The paper has demonstrated that:1. The impact of the shape of hole in2519A aluminum alloy welding joint tothe stress concentration manifests the effect of vertex angle to the stressconcentration. The greater the minimum angle which is between the forced directionand the ligature of apex angle and hole center is, the more the stress concentration is.The affection of outer hole to the stress concentration is far outweighing the innerhole.2. The tensile test sample of2519A aluminum alloy welding joint includinghole penetrated manifests that laboratory finding is basically agreed with thesimulation result.3. In the condition of plane strain compression, the wider the weld joint intwo-dimensional model is, the bigger the stress intensity factor is, so that, two-dimensional model has a great deal of dependence on width of weld joint; Stressintensity factor and equivalent stress of type X and K of groove type inthree-dimensional model are less than type V of groove, so groove type withgeometrical symmetry would improve the fracture toughness of welded joint.4. Stress intensity factor is increased with the minimum angle changing fromdegrees0to45°, which is formed by crake extended line and the ligature of cracktip and hole center; Stress intensity factor is declined rapidly with the anglechanging from degrees45to90°; The farther the hole to crack tip is, the smallerimpact of the stress intensity factor of crack is; the stronger the weld joint elasticmodulus is, the weaker the stress intensity factor of crack tip is; The size of hole hasremarkable effect on the stress intensity factor of crack tip: that the bigger the holeis, the larger the stress intensity factor is; Big hole has strong appeal on crack, whichrestrains the affect of small hole to crack to some extent.Has researched the damage discipline of2519A aluminum alloy welding jointincluding hole and faulty crack, this thesis has significant reference value in choiceof welding groove, improvement of wire, and optimization of technologicalparameter.