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The Vibration Effect by Induced Pulsation Pressure to the Fatigue Crack of the Dampener Fitting Welding Zone

항공기용 유압 펌프의 맥동 압력에 의한 감쇄기 용접부위 균열 개선 연구

  • Received : 2017.05.24
  • Accepted : 2017.07.07
  • Published : 2017.07.31

Abstract

Aircraft can often be exposed to a variety of environments and vibrations such as engine, hydraulic pump, aerodynamic force. These may cause cracking and destruction of the mechanical structure and sub-components by high-cycle fatigue. The axial piston type pump which is usually applied to the aircraft hydraulic pump can be necessarily accompanied by the fluid pulsation by continuous rotation of the axial piston. The fatigue crack was identified at the dampener fitting welding zone to prevent vibration damping during the running of aircraft equipped with this type of pulsation hydraulic pump. In order to understand the root cause of this matter, fracture and component analyses were carried out and also integral type dampener fitting was applied to prevent recurrence of the crack as a subject of design improvements. Structural integrity stress analysis, fatigue analysis, qualification test and aircraft system equipped test was conducted to verify the design validity in application to integral type dampener fitting. The test results were sufficiently satisfactory with the demand lifetime of the material from the various types of test as conducted and the subject of design improvement in this study could be objectively evaluated that shall be applied to the operational aircraft.

Keywords

Dampener;Fatigue Crack;Hydraulic Pump;Helmholtz;Pulsation Pressure;Ripple

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