Dynamic response of airplane structure during takeoff and landing accidents
Mathematics. Physics. Mechanics
Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
AbstractThe study was perform to examine the dynamic response of an airplane and its payload during takeoff and landing accidents, such as collisions with a plane wall, a runway or a ground. The initial conditions for the numerical simulation of airframe dynamics problem correspond with real accidents conditions for the considered aircraft’s type.
A modeling of the structural dynamics of aircrafts under impact loads is a quite difficult problem even in simplified problem statement, so that only numerical simulation can be efficient. To solve these problems of computational mechanics the explicit algorithms are most useful. Here the finite element software LS-DYNA is used to simulate the nonlinear transient dynamic response of airframe structures. The structural elements of the airplane’s fuselage and center wing section was modeled as resultant beams with concentrated masses at the location of nonstructural units such as fuel tanks, avionics, etc. External payloads on central and two lateral hardpoints were modeled as the beams with the stiffness and the density being constant per length. The appropriate initial conditions and properties of obstacles (structural walls, runways or ground) have been considered.
The total accelerations time dependencies were obtained for both of airframe and payload. The peak acceleration of payload were calculated for each case. The strength of payload’s suspension points was estimated.
The analysis of the structural dynamics of aircrafts during different accidents is very important to estimate the impact effect to the crew, payload, some structural elements, and avionics. The risk of triggering explosive and flammable onboard items can be also estimated.
Keywords:airplane, accident, finite element method, beam, dynamic response, acceleration, impact, airframe, damping, bilinear material model
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