Mode screening method for large bundled rockets

A screening method and modal technology, applied in the field of modal screening of large-scale bundled rockets, can solve the problems of inaccurate rocket modal screening methods and large local modal screening errors of rockets, and achieve accurate screening, improved accuracy, and improved accuracy. The effect of enriching modal information

Active Publication Date: 2021-01-15
DALIAN UNIV OF TECH
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  • Abstract
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Problems solved by technology

[0005] In order to solve the problem that the existing rocket modal screening method is not accurate enough, and the local modal screening error of the rocket is relatively large

Method used

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  • Mode screening method for large bundled rockets
  • Mode screening method for large bundled rockets
  • Mode screening method for large bundled rockets

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Experimental program
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Embodiment 1

[0055]Embodiment 1: A large-scale bundled rocket mode screening method, including the following steps: each mode mode is the overall performance of all station displacements. According to the beam element model of the launch vehicle, the x direction is the longitudinal direction of the rocket, so that all The normalized sum of squares of the modal displacement in the x, y, and z directions of the site (normalized according to the maximum modal displacement, that is, the modal data divided by the modal data with the largest absolute value) is:

[0056]

[0057]Where uxij , Uyij And uzij It is the normalized displacement mode of the j-th station in the x, y, and z directions when the i-th mode is the mode, and N is the total number of core-level or booster stations. Let the sum of squared normalized displacements of all stations x in the horizontal direction be:

[0058]

[0059]Let the normalized sum of squared displacements of all stations y be:

[0060]

[0061]Let the sum of the squared normalized ...

Embodiment 2

[0096]Embodiment 2: A modal screening method for large-scale bundled rockets, including the following steps:

[0097](1) Normalize the rocket modal data components;

[0098](2) Calculate the S of the core and booster respectivelyiu , Six , Siy , Siz , Sir, Sirx , Siry , Sirz , Where Siu It is the sum of squared normalized displacements in the three directions of x, y, and z. SirIs the sum of squared normalized angular displacements around x, y and z, Six , Siy , Siz Respectively represent the sum of squared normalized displacements in one direction of x, y, z, Sirx , Siry , Sirz Respectively represent the sum of squares of normalized angular displacements in one direction around x, y, and z;

[0099](3) Bring in the modal characterization coefficients to obtain η in bending, torsion and longitudinal vibration modesw, ΗnAnd ηz. The largest η is the modal type of the core stage or booster;

[0100](4) Calculate the specific gravity coefficient λ, and judge whether it is a local mode by the value ...

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Abstract

The invention discloses a modal screening method for a large bundled rocket, and belongs to the overall field of launch vehicles, solving the problems that according to an existing rocket modal screening method, rocket modal screening is not accurate enough, and the rocket local modal screening error is large. The modal screening method is characterized in that normalization processing is carriedout on rocket modal data components; core-level and booster modal data are fully utilized; the related normalized displacement quadratic sums of a core level and a booster are calculated respectively;characterization coefficients eta w, eta n and eta z in bending, torsion and longitudinal vibration modes are solved, and the maximum characterization coefficient eta is the modal type of the core level or the booster; and meanwhile, a new specific gravity parameter is provided and used for better judging the local mode. The modal screening method has the effect that the modal screening result ofthe modal screening method is higher in accuracy.

Description

Technical field[0001]The invention belongs to the general field of launch vehicles and relates to a method suitable for modal screening of large-scale bundled rockets.Background technique[0002]Large-scale bundled rockets have the characteristics of dense low-frequency modes and serious vertical and horizontal torsion coupling, which brings difficulties to the modeling and simulation of rocket attitude dynamics. And because of the low-frequency dense modal characteristics of the rocket, the modal order that needs to be considered in the design simulation is very high, and the modal shape is complicated. Therefore, accurate modal screening is very important for the study of the dynamic characteristics of the rocket structure and the attitude control design.[0003]Existing rocket modal screening methods include rocket modal rapid automatic arrangement technology, which mainly uses the six component values ​​of each modal head at a certain moment (usually the theoretical cusp of the rock...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G06F30/20
Inventor 谭述君胡明明何骁
Owner DALIAN UNIV OF TECH
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