A Discrimination Method for Integral Dynamic Failure Moment of Steel Truss Tower Structure

Abstract

The invention discloses a method for discriminating the overall dynamic failure time of a steel truss tower structure based on finite element software, the steps of which are: S1, constructing a finite element model; S2, performing dynamic time history analysis to obtain an energy curve; S3, The ordinate E of the characteristic energy Eeig curve Gi The ordinate of the curve with the input energy Eint is E Ti , if E Gi＜ E. Ti becomes E Gi＞ E. Ti , then the corresponding time point T i is the moment of instability of the steel truss tower structure finite element model; S4, extract the displacement time history curve of the tower top of the steel truss tower structure, take the moment when the displacement of the tower top reaches 1 / 50 of the tower height as time A, and The moment when the displacement of the top of the tower reaches 1 / 10 of the height of the tower is time B; i Compare with time A in descending order, if T i ≥B or T i ≤A, the corresponding time point T i discarded, the overall dynamic instability moment of the steel truss tower structure {T i}, the largest element T max That is, the failure time of the steel truss tower. The method is simple to operate, the result is stable and reliable, and the accuracy is high.

Description

technical field [0001] The invention belongs to the technical field of steel structure dynamic stability analysis, and in particular relates to a method for discriminating the overall dynamic failure time of a steel truss tower structure based on finite element software. Background technique [0002] Steel truss tower structures, especially high-flexible structures such as widely distributed transmission towers, due to their small damping and wind sensitivity, their normal operation is the main issue for power grid security. Analyzing the failure mechanism of the transmission tower system under various dynamic effects is conducive to reducing disaster losses in the design process, and the primary problem in studying the dynamic failure mechanism of transmission towers is to accurately determine the failure time of transmission towers under dynamic effects. [0003] At present, there are several methods for discriminating dynamic failure based on finite element software: [...

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Problems solved by technology

[0007] The prerequisite for the first two methods is that the motion system is a conservative system, and the rationality of extending it to a non-conservative system has not been proven.

The third method is only implemented by the author's programming, and the operability is not high, so it has not been widely popularized.

The above three methods are structural stability judgment methods, and the instability of the steel truss tower is only a necessary condition for failure, that is, the failure of the steel truss tower is caused by dynamic instability, and dynamic instability does not necessarily lead to failure

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