Method for performing a ground vibration test in airplanes
First Claim
1. A method for performing a ground vibration test on an airplane, comprising the following steps:
- a) placing measuring transducers in an area of the airplane,b) keeping the airplane undamped and rigidly in place in at least three holding points such that the holding points bring about a substantially rigid coupling between the airplane and ground,c) exciting the airplane to vibrate with a plurality of vibration exciters,d) measuring values and evaluating the measured values obtained by the measuring transducers, ande) mathematically canceling out influence of rigid holding at the holding points during the ground vibration test or after the ground vibration test.
2 Assignments
0 Petitions
Accused Products
Abstract
The invention relates to an improved method for a ground vibration test (so-called “ground vibration test”) on an airplane. In the method according to the invention, the airplane is jacked up essentially undamped (“rigidly”) in conventional holding points with lifting devices. For purposes of the ground vibration test, the airplane is then excited to vibrate in a known manner using a plurality of vibration exciters, and the vibrations are acquired with a plurality of measuring transducers, in particular accelerometers. A dynamic vibration model of the airplane theoretically calculated beforehand can here be adjusted. The boundary conditions are removed during or after the ground vibration test, meaning the influence of the lifting device is “mathematically canceled out”, so that the determined measured values reflect the so-called “free-free” state of the airplane, as if the airplane had actually been in free flight during the ground vibration tests.
-
Citations
19 Claims
-
1. A method for performing a ground vibration test on an airplane, comprising the following steps:
-
a) placing measuring transducers in an area of the airplane, b) keeping the airplane undamped and rigidly in place in at least three holding points such that the holding points bring about a substantially rigid coupling between the airplane and ground, c) exciting the airplane to vibrate with a plurality of vibration exciters, d) measuring values and evaluating the measured values obtained by the measuring transducers, and e) mathematically canceling out influence of rigid holding at the holding points during the ground vibration test or after the ground vibration test. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A system for performing a ground vibration test on an airplane, comprising:
-
at least one holding device that provides an undamped, and substantially rigid support for the airplane in at least three holding points such that the holding points bring about a substantially rigid coupling between the airplane and ground; a plurality of vibration exciters operating to vibrate the airplane; a plurality of measuring transducers located in or around the airplane and operating to measure vibration values therefrom; and a processing device comprising an evaluator that implements a predetermined simple rigid holding model for the substantially rigid coupling, that evaluates the measured values obtained by the measuring transducers, and that mathematically cancels out influence of the rigid holding at the holding points.
-
Specification