Method for simulating random temperature field of steel box beam of bridge construction

Abstract

The invention relates to a method for simulating a random temperature field of a steel box beam of a bridge construction. According to the method, a change characteristic of an actual temperature and a statistical characteristic of a temperature value of the steel box beam of the bridge construction are fully taken into account, and a numerical method is used for realizing the simulation for the random temperature field of the steel box beam of the bridge construction, thereby providing an effective method for acquiring the random temperature field of the steel box beam. The problem that a temperature load data is seriously insufficient during an analysis process for a temperature effect of the steel box beam is efficiently solved. The method comprises the following steps: firstly, performing statistic analysis and acquiring a probability density function of temperature and temperature difference according to a finite actual measured temperature data of the steel box beam; utilizing extreme value analysis to acquire a temperature range and a temperature difference range in a simulating time span; dividing the temperature range and the temperature difference range into a plurality of sub-ranges, utilizing an inverse transformation sampling method to generate a sample for each sub-range, and acquiring a random temperature sample in the simulating time span; and lastly, rearranging simulating samples on the basis of a daily variation law and a seasonal variation law of the temperature of the steel box beam, thereby acquiring a temperature schedule in the simulating time span.

Description

technical field [0001] The invention relates to a method for simulating a random temperature field, in particular to a method for simulating a random temperature field applied to a steel box girder of a bridge structure, and is mainly used in the field of health monitoring of civil engineering bridge structures. Background technique [0002] Due to the high thermal expansion coefficient and good thermal conductivity of steel, the steel box girder of bridge structure is very sensitive to temperature changes. The uneven solar radiation and the temperature gradient stress caused by the sudden change of atmospheric temperature also have a significant effect on the steel bridge. Temperature load has become one of the main loads of long-span steel box girder bridges during their service period, and the temperature field and stress analysis of bridge structures has gradually become an important part of the life-span assessment of bridge structures. To evaluate the temperature effe...

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Problems solved by technology

However, the inverse transform sampling method needs to find the inverse function and derivation of the target probability density function. The probability density function of the measured temperature of the steel box girder is generally more complicated, and it is impossible to find the analytical expression of the inverse function of the temperature probability density function, which leads to the inverse transform sampling method. It is difficult to realize in the temperature field simulation of steel box girder

[0004] To sum up, although the inverse transform sampling method has many advantages, it cannot be applied to the simulation of the random temperature field of steel box girders in bridge structures. There is an urgent need for an inverse transform sampling method that integrates the statistical characteristics and time-varying laws of measured data with extreme value analysis. The combined improved inverse transformation sampling method simulates the random temperature field of the steel box girder, and makes the simulated random temperature field not only conform to the temperature change law of the steel box girder throughout the year and from day to night, but also meet the requirements of the steel box girder. Statistical characteristics of temperature to meet the needs of bridge structure life assessment

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