Research On Bend Forming Of AZ31 Wrought Magnesium Alloy Integral Panel

Integral panel is an important part of the aerodynamic shape of aircraft,and the main load-bearing component of fuselage and wing,etc.Magnesium alloy is expected to be applied for integral panel because of its excellent performance.Therefore,it is critical to investigate the forming of magnesium alloy panel.The bending forming of AZ31 wrought magnesium alloy rib and grid type panels has been investigated in this paper.The stress field,strain field,temperature field and springback law have been numerically simulated by means of finite element software Abaqus.Experiments have been performed on bend forming of magnesium alloy rib and grid type panels.The microstructure of magnesium alloy grid type panel has been investigated by experiments.The progressive bending formed grid type panel has been three dimensionally scanned based on reverse engineering.The radius of the panel has been measured.The main research content and results include:(1)Three-dimensional stress,strain and temperature field of AZ31 magnesium alloy flat plate;stress field,strain field and temperature fields as well as springback rules of magnesium alloy rib and grid type panels during bend forming have been numerically simulated by finite element software Abaqus.During bend forming process,the equivalent stress and strain of the rib are bigger while that on the panel are smaller for magnesium alloy rib type panel.The equivalent stress and strain on the transverse rib is bigger while that is smaller on the panel for magnesium alloy grid type panel.(2)The bending forming experiments have been performed on AZ31 magnesium alloy rib and grid type panels,meeting the expected requirements.The bending springback rule measured by experiment agrees well with that of simulation.The maximal relative error of springback angles between the experiment and simulation result is 9.01%.(3)The microstructure evolution rule of magnesium alloy grid type panel has been investigated by experiments.With the increase of reduction,dynamic recrystallization occurs on the concave side,and the grain refinement became more obvious.The convex grains are elongated along the deformation direction,and the grains become coarser and coarser.(4)Three-dimensional scanning experiment has been carried out on the AZ 31 magnesium alloy grid panel formed by progressive bending.The 3D model of the formed panel is obtained.The curvature radius of the outer arc of the magnesium alloy panel obtained by scanner is close to that measured by three-point method.The maximum error is 2.33%.The relationship between the arc curvature radius and the reduction of magnesium alloy panel in progressive bending is obtained.