The Research Of Circular Steel Pipe Axial Force Performance Considering The General Corrosion

The first prosperous period of the development of space steel structure appears in the 80’s of last century. It has been more than 30 years ago and a large number of space steel structures built in that period will be in the later period of the designed service life and the durability problems especially corrosion problem gradually come out. Therefore, it is of great significance to study the mechanical properties of steel structure after corrosion. At preasent, the research on the corrosion of steel structure is mainly concentrated on the material field and of which the mechanical properties of steel structure after corrosion is less. Moreover, to the study on the circular steel tubes which are the most common members of the space steel structure after corrosion, there is limited systematic research. In order to know more about the mechanical property of the space steel structure after corrosion and provide technical reference for the performance safety evaluation of the in-service space steel structure after corossion, this paper considers the research on the mechanical property of the circular steel tube after corrosion. The main research contents of this paper are shown as followed:1. Study on circular steel tube bearing capacity decreasing after uniform corrosionThe accelerated corrosion method for the steel structure members is established based on the outdoor periodic atomizing compound experiment. Through the contrast of the accelereted corrosion results and the natural corrosion results, the accelerated corrosion method is verified. Then the circular steel tubes are corrode by uniform corrosin experiment and are tested by axial compressive experiment. Equivalent section reduction method is developed to analyse the mechanical propertied of corroded components and analysis results agree well with test ones which proved that this method is feasible. The influence of different uniform corrosion on the bearing capacity of circular tube is studied, based on which the functional relationships between the weight loss rate and ultimate bearing capacity and yield bearing capacity are established.2. Study on circular steel tube bearing capacity decreasing after local corrosionLocal equivalent section reduction method is developed to study the circular steel tubes bearing capacity after local corrosion. And design the local accelerated corrosion experiment and axial compressive experiment of circular steel tubes. The comparison of experiment result and simulation one shows the reliability of simulation method. Considering the actual engineering corrosion characteristics and combined variables of the member section, corrosion position, corrosion size and corrosion depth, the large scale parameter analysis and sensitivity analysis of the circular steel tube bearing capacity after local corrosion are discussed. The result shows that the circular steel tube bearing capacity after local corrosion is influenced by parameter degree including section, corrosion condition.3. Study on circular steel tube bearing capacity after corrosion with different slenderness ratioThe stability bearing capacity of circular steel tubes which have different slenderness ratio, different corrosion modes and different degrees are analysed based on the results of previous research. The stability bearing capacity of circular steel tubes with different corrosion modes under different slenderness ratio are mastered and the influence of slenderness ratio on the bearing capacity of circular steel tube after corrosion is obtained. The research results can serve as references for the safety performance evaluation of space steel structure after corrosion.