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Pipeline leakage and pipeline internal corrosion are two serious threats to pipeline safety operation. In this study, based on the measurement theory of pipeline internal diameter variation and a numerical simulation analysis of existing sensor shortcomings, a novel FBG pipe-fixture sensor is designed and developed to detect pipeline leakage and monitor pipeline internal corrosion simultaneously. A calibration test is conducted, and the test results indicate that the FBG pipe-fixture sensor solves the problem of a large difference between the test values and the theoretical values and eliminates the limitation of measurement range. To validate the actual performance of the sensor, a pipeline leak detection test and a pipeline internal corrosion monitoring test are, respectively, conducted on a steel pipe leak test platform and a steel pipe with different simulated corrosion levels. The test results demonstrate that the FBG pipe-fixture sensor can effectively detect pipe leakage and decrease the localization error of the leakage point to within 1 m. The sensor can also effectively monitor pipe internal corrosion and evaluate the internal corrosion degree with a measurement accuracy of 0.1 mm. The novel FBG pipe-fixture sensor may be a potential sensor for pipeline leak detection and pipeline internal corrosion monitoring.

Based on VB platform, a stress redistribution and cutting simulation system of enlarging the hole of coal and rock is developed by using the computer technology, finite element analysis, the second development, combining with structure parameter selection and Object-Oriented Programming method as well as using VB to encapsulate ANSYS and writing APDL command to call the ANSYS calculation program. The soft provides a convenient parameters input and graphical interface, and has completed the preprocessor simulation solving of the model and analysis of the results. Even not capable of mastering the finite element theory and FEA soft, users can use the system to perform the stress analysis and simulation when enlarging the hole of coal and rock easily.

Effects of mold electromagnetic stirring (M-EMS) on the solidification structure of 45# steel billet were investigated by examination of interdendritic corrosion. The results show that the primary and secondary dendrite arm spacings increase from the edge of the billet to the center and decrease obviously with increasing electromagnetic torque, which will be beneficial to refine the solidification structure and enlarge the equiaxed crystal zone. The ratio of equiaxed crystal increases by 15.9% with the electromagnetic torque increasing from 230 to 400 cN·cm. The increase of stirring intensity can improve the cooling rate and the impact of M-EMS on it reduces from the edge of the billet to the central area, where the cooling rates are similar at different torques. The closer to the central area, the less the influence of M-EMS on the cooling rate is. The ratio of the primary to secondary dendrite arm spacing is approximately 2.0, namely, λ1≈2λ2, and is constant irrespective of the stirring intensity and position of the billet. Original position analysis (OPA) results indicate that the center segregation of the billet is greatly improved, and the more uniform and compact solidification structure will be obtained with the increase of stirring intensity.

Particle-enhanced is the way to improve properties of solder alloys. In the present work, the influence of Ag particle-enhanced on the wettability and creep rupture life of 99.3Sn0.7Cu eutectic solder with Ag content of 1vol% to 10vol% were investigated. It was indicated that the wettability of the composite solders could be improved by adding minute amount of Ag particles. With increasing the amount of Ag particles, the spreading areas of the composite solders increased when Ag was below 5vol%. When Ag was above 5vol%, the spreading areas started decreasing. When Ag content was up to 10vol%, the wettability of the composite solder sharply deteriorated. In addition, the creep rupture lives of the composite solders were longer than that of 99.3Sn0.7Cu eutectic solder at the same condition. When Ag content was 5vol%, the creep rupture life of the composite solder was the longest among the investigated composite solders and about 23 times of that of 99.3Sn0.7Cu eutectic solder.

The simplified computational models of high-voltage transmission tower–line system under out-of-plane and in-plane vibrations are presented due to seismic excitations in this paper. The equations of motion are derived and the computer program is compiled to obtain the earthquake responses of the coupled system. To verify the rationality of the proposed approaches, the shaking-table experiments of the coupled system of transmission lines and their supporting towers are carried out and the results indicate that the errors of theoretical and testing results of systemic seismic responses are within the acceptable arrange in engineering area. Based on these studies, a simplified analysis method is proposed to make the seismic response calculation of coupled tower–conductor system faster and more effective.