A Static Equivalent Reliability Evaluation Method for Service Structures Based on Interval Set Envelope Function

Abstract

The invention discloses an existing structure static equivalent reliability evaluation method based on an interval set envelope function. The method comprises the steps that the envelope function is introduced into the reliability problem of a dynamic structure, a failure domain of the multi-parameter structure uncertainty changing along with time is approximately constructed through an envelope surface, a dynamic problem is transformed into a static problem, and effective evaluation on the structural security situation is achieved through reliability degree index calculation. According to the method, a partial differential equation is defined according to the character that the envelope surface in the internal set envelope function is tangent to a failure boundary hypersurface continuously changing along with time, and a risk moment corresponding to an extension point is solved; a limited dimensional static failure domain equivalent to an original dynamic problem at a limited risk moment is obtained by building a multi-dimensional hypercube model containing the correlation; the static equivalent reliability degree calculation process of an existing structure is finally achieved on the basis of a volume ratio idea, and the traditional time-varying reliability calculation scale is greatly reduced while the precision is guaranteed.

Description

technical field [0001] The present invention relates to the technical field of dynamic response prediction and safety assessment of service structures, and in particular to a static equivalent reliability evaluation method for service structures based on interval set envelope functions, which is a reliable method for service structures considering time-varying uncertainties. Reliability analysis provides a feasible equivalent transformation method for breaking through the bottleneck of large-scale and low-efficiency non-probabilistic time-varying reliability calculations for large and complex structures. Background technique [0002] In-service structures, also known as in-service structures or existing structures, are inevitably accompanied by problems such as structural aging, performance degradation, and time-varying loads during their construction and use. The attenuation of structural safety indicators over time is also irreversible. If the behavior evolution law of the...

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Problems solved by technology

The method based on the extreme value response needs to obtain enough samples to determine the statistical characteristics of the response extreme value at different times, and the engineering practicability is not strong; the method based on the first crossing needs to obtain the crossing rate index of the response to the first breakthrough threshold, which is difficult to calculate. and cannot accurately simulate multiple crossing situations

In short, compared with static reliability analysis, the traditional structural time-varying reliability analysis method consumes a lot of computing resources due to the addition of time considerations.

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