Study on micro crack propagation mechanism of ferrite-pearlite gas transmission pipeline steel with lamellar structure.

The deformation and failure characteristics of pipeline steel depend on its atomic structure and microstructure. Based on the serial multi-scale analysis technology, the ferrite/cementite (α-Fe/FeC) lamellar atomic structure with Bagaryatskii orientation relationship is established. In order to obtain the experimental sample of the lowest energy state, The step-by-step relaxation method of conjugate gradient energy minimization and constant temperature and constant pressure relaxation under NPT conditions is carried out, and the energy state and atomic structure of the relaxed samples are analyzed.

Study on Overpressure Propagation Law of Vapor Cloud Explosion under Different Building Layouts.

To determine and optimize the emergency evacuation path of personnel in the case of vapor cloud explosion caused by pipeline leakage and improve the safety control measures in the high-consequence areas of gas pipelines, this study was conducted. This work mainly studied two questions: whether various research methods applicable to the solid explosive explosion are also applicable to vapor cloud explosion and the influence of different building layouts on the overpressure propagation law of vapor cloud explosion. First, the applicability of several empirical models and computational fluid dynamics (CFD) methods in vapor cloud explosion overpressure prediction is systematically compared and analyzed.