In the finite element ANSYS software established simplified structure model, simplified the structure into axisymmetric model, alternated the structure size. Using order flow to compute stress intensity factor around the singularity, then analysed the relation between the stress intensity factor and the structure size and compared to the calculation by Jintegral. The results show that the application of J integral calculation KⅠ has feasibility.

 

The reliability of pressure pipeline containing defects in engineering is very important. The pipeline of the oil industry may contain types of potential defects. It should be considered the defected size, the uncertainty of the loaded parameters, so introduced the Monte Carlo method to use random sampling for these uncertain parameters. Monte Carlo method is based on the probability and statistic theory method, it can realistically describe the characteristics of the random things, and overcome the disadvantage of the deterministic failure analysis method, more accurate calculate the failure probability of the pipeline, it provides a technical means for diagnosing system security of petrochemical enterprise.