A flexible structure and design method for rocket engine thrust fidelity measurement

Abstract

A flexible structure and design method for rocket engine thrust fidelity measurement are provided. The flexible structure comprises an upper body of an elongated cylindrical structure, the lower end of the upper body is connected with the upper end of a transitional body; the transitional body is of a structure similar to a half spheroid; the lower end of the transitional body is connected with the upper end of the weak body; the weak body is a rotary structure formed by rotation of two circular arcs around the axis; the lower end of the weak body is connected with the top of the lower body; the lower body is a flat cylinder structure; the upper body, the transitional body, the weak body and the lower body are integrally cut and formed. The design method is to analyze the engineering situation and define the stress condition and boundary condition. Then the topology reduction optimization is carried out to determine the initial shape of the flexible structure and the topology reductionoptimization is carried out. Repeated iteration is performed to achieve the ideal value; then the three-dimensional structure is designed on the basis of two-dimensional images. The three-dimensionalfinite element simulation analysis is carried out; whether the structure is reasonable or not is judged and the structure is finally output. The flexible structure of the invention has less influenceon the force transmission effect, so that the experiment result is more accurate.

Description

technical field [0001] The invention relates to the technical field of engine thrust measurement, in particular to a flexible structure and a design method for fidelity measurement of rocket engine thrust. Background technique [0002] In the vector thrust experiment of the aerospace liquid oxygen kerosene engine, in order to ensure the vector stability of the engine thrust, it is necessary to test the degree of load offset under the action of the engine thrust. However, due to the small offset angle of the vector thrust, the ratio between the longitudinal thrust and the lateral thrust is greatly different, and the structural rigidity of the connecting device of the side load sensor itself hinders the true measurement of the vector thrust. The flexible connector with high rigidity ratio can realize the fidelity transmission and measurement of the vector thrust, and the flexible connector plays a key role in the measurement of the experimental results. [0003] The existing ...

AI Technical Summary

Problems solved by technology

[0003] The existing flexible structure has weak parts of two thin-walled structures, and the directions of the two thin-walled structures are perpendicular to each other, which is not a symmetrical structure of revolution, resulting in relatively large rigidity along some radial directions, which is not easy to deform, and will cause the engine to shift Produce a large obstacle and affect the force measurement results of the sensor at the same time

However, the radial stiffness in a certain direction is very small. When the offset direction of the measured object is consistent with the direction of the small radial stiffness, it can meet the engineering needs, but it has a great influence on the pose transformation of the measured object, which makes the experimental results Inaccurate

This characteristic leads to strict requirements on the installation direction and position of such flexible connectors, and this kind of connectors cannot be used in experiments where the pose transformation of objects is uncertain

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