APPLICATION OF ELECTRODYNAMIC TREATMENT WITH AMPLITUDE-FREQUENCY CONTROL OF CURRENT PULSES FOR LIFE EXTENSION OF AIRCRAFT STRUCTURES OF LIGHT ALLOYS

摘要

The pulsed electric current (PEC) generator of a new generation with the controlled amplitude-frequency characteristics of PEC for electrodynamic treatment (EDT) of thin-sheet metal structures was designed and manufactured. The use of a new class of equipment allows a significant extension of capabilities of electrodynamic effects due to the controlled synchronization of the EDT dynamic and electric pulse components. The effect of EDT on reducing the level of residual welding stresses in magnesium alloy ML10 joints was investigated. As the investigated specimens the fragments of the shell of the intermediate body of the aircraft engine D-36 containing repair welds were used. It was found that EDT allows reducing the level of residual welding stresses from 120 to - 40 MPa, providing their transition from tensile to compressive ones. It is shown that the local plastic deformation applying EDT of specimens of an aircraft wing stringer of aluminum alloy D16 in the area of technological holes 1.6-2.5 times increases the resistance to a delayed fracture.