This paper establishes the simulation model of the electronic unit pump diesel engine with Matlab/Simulink and AMESim. Provide a theoretical basis for the study of electronic unit pump diesel. The diesel model is built with Matlab/Simulink simulation software and the electronic unit pump is constructed in AMESim environment. To evaluate the model, a co-simulation method with AMESim/Simulink is used. The simulation results show the model is available. And it is significant in theoretical study of electronic unit pump diesel.

It is impossible to keep pipelines free from defects in the manufacturing, installation and servicing processes. In this paper, pre-tension deformation was used to imitate the defects of the part of material and the U-notch specimens were used to investigate the fatigue crack initiation life of X60 pipeline steel after pre-tension straining with ductile deformation of 0,5%,10% and 15%. Test results show that the prestrain had apparent straining hardening effects, but decreased the plasticity of pipeline steel. The prestrain prolonged the fatigue crack initiation life, and increased resistance coefficient and equivalent stress threshold of the fatigue crack initiation.

It is impossible to keep pipelines free from defects in the manufacturing, installation and servicing processes. In this paper, pre-tension deformation is used to imitate the defects of the part of material and the electric method is used to measure the distance of the fatigue crack. Experimental investigations were carried out on the fatigue crack propagation characteristics of X60 pipeline steel after different degrees of pre-tension deformation Test results show that the fatigue crack propagation was augmented with the pre-tension deformation increase, especially the crack propagation at the near threshold section. The results of quantitative analysis show, the pre-tension deformation reduced the fatigue crack propagation threshold and increased the crack propagation coefficient; consequently the fatigue performance of the part of mechanical damnification was degenerate.

It is impossible to keep pipelines free from mechanical damage in the manufacturing, installation and servicing processes. In this paper, the geometric model for fatigue life of pipeline steel was introduced. The local plastic deformation was considered to imitate the mechanical damage on the pipe. The estimation models of the fatigue crack initiation life and the fatigue crack propagation life were proposed according to the plastic deformation. The result is expected to be beneficial to the understanding of the effect of damage on the safety of pipelines and fatigue life prediction.

Natural gas compressor is the absolutely necessary link of natural gas storage and transportation technology. The safety operation of the exhaust steel tube directly influences the ability of natural gas gathering and transportation system. In this paper, the accident of the exhaust steel tube explosion of natural gas compressor was carried out to study the reasons of the failure using methods of macroscopic analysis, size measurement and SEM et al and proposed the safety countermeasures. The results show that the failure of exhaust steel tube related to the wicked service conditions, rough machining, the fatigue crack initiation and propagation. The sulfide stress corrosion (SSCC) and the longitudinal processing damage accelerate the fatigue crack propagation rate.