Safety assessment method for pressure-bearing structure with creep damages and volume defects

Abstract

The invention relates to a safety assessment method for a pressure-bearing structure with creep damages and volume defects. The safety assessment method comprises the following steps of (1) establishing an elastoplastic constitutive model for the pressure-bearing structure working for a long time in order to predicate elastoplastic response of the pressure-bearing structure and make a preparation to estimate bearing limit of the pressure-bearing structure; (2) doing research on an expansion process and a failure mode of a plastic range of the pressure-bearing structure with various pits and local thinning defects under loading action of internal pressure or bending moment through a finite element method, doing research on influence of different creep damages caused by various pits and local thinning defects on bearing limit of the pressure-bearing structure and calculating out a bearing limit value of the pressure-bearing structure quantificationally; (3) determining safety assessment steps and performing safety assessment on the pressure-bearing structure with the creep damages and/ or the volume defects. By means of the safety assessment method, effects of the creep damages and the volume defect dimensions are tightly combined for the first time to work out a safety assessment standard suitable for the pressure-bearing structure working for a long time under high temperature and high pressure. Therefore, the safety assessment method for the pressure-bearing structure with creep damages and volume defects has a clear physical meaning and is adaptive to projects.

Description

technical field [0001] The invention relates to a safety assessment method for high-temperature pressure-bearing structures, in particular to a method for safety assessment of high-temperature pressure-bearing structures after long-term service involving creep damage and volume defects. Background technique [0002] High temperature and high pressure processes are widely used in electric power, petrochemical, nuclear energy, aerospace and other industrial fields. Creep damage will inevitably occur in pressure-bearing structures that work for a long time under high-temperature and high-pressure conditions. In addition, volume-type defects such as slag inclusions, pits, and thinning often occur in pressure-bearing structures during manufacturing and work. These creep damages And volume defects will weaken the load-bearing limit of the pressure-bearing structure, bring safety hazards to the equipment, and may even cause accidents such as leakage and explosion. Equipment that c...

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Problems solved by technology

[0004] In my country, a number of patents have disclosed methods for safety assessment of high-temperature and high-pressure equipment, such as Chinese patent CN201010130569 "Safety control method for pressure pipelines containing incomplete penetration defects under internal bending and torsion complex loads", CN

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