Multi-objective optimization and multi-attribute decision-making method for steel structure fatigue crack CFRP reinforcement

Abstract

The invention discloses a multi-objective optimization and multi-attribute decision-making method for steel structure fatigue crack CFRP reinforcement, and the method comprises the following steps: 1) a key design variable and a main optimization objective of a steel structure fatigue crack CFRP reinforcement process are determined, and a mathematical model of a steel structure fatigue crack CFRP reinforcement multi-objective optimization problem is built; 2) a fatigue damage model of the reinforced steel structure is defined, and probability distribution of fatigue damage parameters and extension threshold values is determined; 3) based on computer experiment design and an agent model strategy, an optimization objective equation for describing the correlation between the safety crack arrest probability of the reinforced structure and the key design variables is established; 4) through theoretical analysis, an optimization objective equation for describing the correlation between the CFRP reinforcement total cost and the key design variables is established; 5) a mathematical model of the CFRP reinforcement multi-objective optimization problem of the steel structure fatigue cracks is perfected, and the optimal reinforcement scheme is solved and obtained through a multi-objective optimization algorithm and a multi-attribute decision-making method. The efficiency and reliability of the CFRP reinforcement of the cracked steel bridge are improved.

Description

technical field [0001] The invention belongs to the technical field of steel structure fatigue crack maintenance, in particular to a multi-objective optimization and multi-attribute decision-making method for steel structure fatigue crack CFRP reinforcement. Background technique [0002] Fatigue cracking is one of the main problems limiting the application and development of steel structures. Fatigue cracking affects the safety of steel structures and increases financial pressure on management. Therefore, the development of an efficient and reliable fatigue crack repair method is of great significance for improving the service life of steel structures in my country and reducing the corresponding maintenance financial expenditure. [0003] At present, the maintenance measures for fatigue cracks in steel structures mainly include crack arrest hole method, steel plate reinforcement method, repair welding method and so on. Although the above method can inhibit the development ...

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Problems solved by technology

Although the above method can inhibit the development of fatigue cracks to a certain extent, it has the following disadvantages more or less: it introduces new residual stress, causes secondary damage to the structure, increases the self-weight of the structure, and consumes more manpower

[0004] However, in the current cases of using CFRP to strengthen cracked steel structures, the relevant configuration parameters of the strengthening scheme are mostly based on empirical design, resulting in unsatisfactory strengthening effects and high maintenance costs

In addition, since the reinforcement effect and maintenance cost are often two contradictory goals, it is difficult to obtain the optimal reinforcement scheme using traditional optimization and decision-making methods

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