Main beam section pneumatic self excitation whole-course numerical modeling method

Abstract

The whole-process numerical simulation method of the aerodynamic self-excited force of the main girder section is to solve the time-domain aerodynamic self-excited force of the main girder section, which is a difficult point in the time-domain analysis of bridge buffeting. Effectiveness. On the basis of the derivation of the existing dynamic equations, a dedicated unit for simulating aerodynamic stiffness and aerodynamic damping—the Aero-dyn18 unit is created, and the relevant parameters, characteristics and structural diagrams of the unit are given. By adding the Aero-dyn18 element to the initial finite element model of the bridge structure, and using CFD technology to determine the relevant parameters of the Aero-dyn18 element, the whole process numerical simulation of the aerodynamic self-excited force of the main beam section can be realized. Obviously, compared with the existing time-domain method of pneumatic self-excited force, this method is simple and practical, greatly improves the efficiency of analysis, saves cost at the same time, and is convenient for popularization and application among engineers.

Description

technical field [0001] The invention relates to a whole-process numerical simulation method of the aerodynamic self-excited force of the main girder section, which is especially suitable for simulating the aerodynamic self-excited force on the main girder section during the time-domain analysis of the chattering response of the bridge. Background technique [0002] With the increasing span of bridge structures, the buffeting analysis of bridges becomes more and more important. There are mainly two types of analysis methods in frequency domain and time domain for chattering response calculation. Early buffeting analysis of bridges at home and abroad was mainly carried out in the frequency domain, but because the frequency domain method can only include a certain number of modes in the analysis process, the statistical characteristics of the structural response value can be obtained, and only linear analysis can be performed. It cannot be well applied to nonlinear structural ...

AI Technical Summary

Problems solved by technology

[0005] (1) Since the existing general-purpose finite element software does not necessarily have a special aerodynamic self-excited force unit, other matrix units with similar characteristics are usually used to simulate the self-excited force in chattering analysis, resulting in increased calculation workload, The probability of error increases, the accuracy of the result decreases, and it is inconvenient to use;

[0006] (2) The aerodynamic stiffness and aerodynamic damping matrix of the main beam unit usually use the aerodynamic derivative obtained in the wind tunnel test as a parameter. Dynamics, CFD) technology in the identification of the latest research results in the field of aerodynamic derivatives has not been fully applied

Images