Experimental verification method for identifying modal parameter of variable mass structure

Abstract

The invention relates to an experimental verification method for identifying a modal parameter of a variable mass structure, and belongs to the technical field of modal parameter identification of structural dynamics. The experimental verification method comprises the steps that a time varying structure with a mass size and mass distribution capable of be controlled accurately with a time varying rule is designed and set up; the modal parameter of the time varying structure is identified under short time invariant assumption; a varying rule of the modal parameter with the time of the time varying structure is obtained and serves as a basis reference; a time varying structure dynamic experiment is performed; a structural dynamic response signal of the time varying structure under specified excitation is measured; measured data is identified by a to-be-verified method; an identification result is compared with the basis reference for verifying the feasibility and the accuracy of the to-be-verified method; the identification result of the to-be-verified method and the basis reference are compared under different experiment conditions; and the robustness of the to-be-verified method is verified. The experimental verification method is simple and reliable.

Description

technical field [0001] The invention relates to an experimental verification method for modal parameter identification of a variable mass structure, and belongs to the technical field of structural dynamic modal parameter identification. Background technique [0002] In engineering practice, the characteristics of structures change with time, and the time-invariant assumption is only a simplified treatment method for time-varying structures under given conditions. As the structural properties that researchers care about and the applications that use these properties continue to increase, especially in the fields of aerospace, machinery, bridges, etc., more and more structures whose time-varying properties cannot be ignored. For example, the total mass and mass distribution characteristics of the launch vehicle in flight change with time due to the continuous consumption of fuel; when the aircraft flies at super high speed, aerodynamic heating will cause the stiffness and dam...

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Problems solved by technology

At present, time-varying structural modal parameter identification methods are mostly verified by numerical simulation, but it is difficult to simulate the measurement noise of the signal in numerical simulation, and the structural dynamic response signal measured under the real working conditions of the time-varying structure Therefore, it has stronger practical significance to verify the method of time-varying structural modal parameter identification through experiments

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