Modal test method for carrier rocket

Abstract

The invention provides a modal test method for a carrier rocket, and the method comprises the steps: obtaining a first-order vibration mode of the carrier rocket in a free flight state at a zero-second moment according to a finite element model, and taking an intersection point of the first-order vibration mode of the carrier rocket and the central line of the carrier rocket as a node position; hosting the carrier rocket with the circumferential outer side, corresponding to the node position, of the carrier rocket as a hoisting point, and arranging an elastic lengthening structure between a rocket body of the carrier rocket and the hoisting wrapping belt so as to eliminate the influence of the bending rigidity of the hoisting beam on the bending rigidity of the rocket body; and obtaining modal parameters of the carrier rocket in a hoisting state. According to the modal test method provided by the invention, the influence of the rigidity of the hanging beam on rocket modal parameters can be reduced, and the reliability of a rocket modal test result is improved.

Description

technical field [0001] The invention relates to the technical field of launch vehicle tests, in particular to a modal test method for launch vehicles. Background technique [0002] For a launch vehicle with a relatively large slenderness, in order to obtain the modal parameters, the conventional method is to convert it into a beam model to obtain the modal parameters of the launch vehicle, and these modal parameters can be provided to the attitude control system for analysis . [0003] For a rigidly connected rocket body, it is difficult to guarantee the accuracy of its model and related parameters obtained through the model only through simulation. In addition, the damping parameters involved in the modal parameters can only be obtained through modal tests. [0004] When carrying out the modal test of the launch vehicle, in order to ensure the authenticity of the test results, the current conventional practice is to carry out the modal test through a simulated arrow with ...

AI Technical Summary

Problems solved by technology

However, in the process of processing and final assembly, the structural properties of the simulated arrow and the flying arrow are not exactly the same, especially the connection stiffness is difficult to guarantee

Using simulated rockets for modal tests not only has low reliability of test results, but also increases development costs and reduces the competitiveness of rocket products

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