Random dynamic load recognition method based on spectrum random finite element model

Abstract

The invention discloses a random dynamic load recognition method based on a spectrum random finite element model. The method comprises the following steps: S1, carrying out modal tests repeatedly under the same working condition on a structure which contains uncertain parameters, and establishing a spectrum random finite element model of an uncertain system; S2, measuring a random dynamic responsesample of the structure which contains the uncertain parameters under the effect of a random dynamic load; S3, recognizing a mean value of the random dynamic load on the structure by using a mean value of a random dynamic response sample; S4, solving a random dynamic response covariance of the structure when only uncertainness of the parameters of the system is considered by using the recognizedmean value of the random dynamic load; S5, calculating an approximate value of the random dynamic response covariance caused by the reason that only dynamic load randomness is considered; and S6, recognizing a statistical characteristic of the random dynamic load. Uncertainness of a dynamic load and system parameters can be considered simultaneously, and by a dynamic response sample of a measuredstructure, the statistical characteristic of the random dynamic load acting on the system of the structure is recognized.

Description

Technical field: [0001] The invention relates to a random dynamic load identification method based on a spectral random finite element model, which belongs to the technical field of indirect identification of dynamic loads. Background technique: [0002] The dynamic load on the engineering structure is very important to the design and safety assessment of the structure. In many cases, the external loads on some engineering structures are difficult to obtain through direct measurement methods, such as aerodynamic loads on aircraft during flight, wind and wave loads on offshore platforms, and contact loads between wheels on vehicles and the ground. Therefore, use It has become a widely used technology to indirectly obtain dynamic load information by measuring the dynamic response of the structure, also known as the indirect identification technology of dynamic load. [0003] The current indirect identification methods for dynamic loads can be mainly divided into frequency domain met...

AI Technical Summary

Problems solved by technology

The existing indirect dynamic load identification methods generally assume that the dynamic model of the structural system is accurate enough, and there is no or only a small uncertainty, that is, the dynamic load identification is limited to the deterministic structure, and it is impossible to consider the variable parameters of the structural system. Certainty

However, in actual engineering, due to manufacturing or measurement errors and the discreteness caused by the material itself, the structural system parameters are often not suitable to be described by a definite value, regardless of the uncertainty of the system parameters will be It will cause errors or even errors in the dynamic load identification results

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