Pipeline plays an indispensable role in process industries,because the progressing crack-like defects of in it may result in serious accidents and significant economic losses.Therefore,it is essential to detect the cr...Pipeline plays an indispensable role in process industries,because the progressing crack-like defects of in it may result in serious accidents and significant economic losses.Therefore,it is essential to detect the cracks occurred in pipelines.The axial crack-like defects in elbows with different angle are inspected by using the T(0,1)mode guided waves,in which different configurations including 45°,90°,135°and 180°(straight pipe)are considered respectively.Firstly,the detection sensitivity for different defect location is experimentally investigated.After that,finite element simulation is used to explore the propagation behaviors of T(0,1)mode in different bend structures.Simulation and experiment results show that the crack in different areas of the elbow can affect the detection sensitivity.It can be found that the detection sensitivity of crack in the middle area of the elbow is higher compared to the extrados and intrados of the elbow.Finally,the mode conversion is also investigated when the T(0,1)crosses the bend,and the results show that bend is a key factor to the mode conversion phenomenon which presents between the T(0,1)mode and F(1,2)mode.展开更多
EGR(Exhaust Gas Recycling)技术近几年已成为发动机节能、减排的一种核心技术,发动机的工况对于EGR波纹管的可靠性要求极为苛刻,而EGR波纹管的材质选择与波形设计是其可靠性的根本。通过选用材质分析与波形设计试验,结果表明:300系不...EGR(Exhaust Gas Recycling)技术近几年已成为发动机节能、减排的一种核心技术,发动机的工况对于EGR波纹管的可靠性要求极为苛刻,而EGR波纹管的材质选择与波形设计是其可靠性的根本。通过选用材质分析与波形设计试验,结果表明:300系不锈钢优良的力学、耐蚀和加工等性能使其成为EGR波纹管材质的首选,这为EGR波纹管提供了高的可靠性与工艺性。EGR波纹管采用液压多波一次成型工艺具有管材壁厚减薄量小,成型尺寸稳定的优点。?形波比U形波管具有更好的拉伸、疲劳性能及应力分布状态。展开更多
基金supported by the National Natural Science Foundation of China(Nos.51575185,51175178)
文摘Pipeline plays an indispensable role in process industries,because the progressing crack-like defects of in it may result in serious accidents and significant economic losses.Therefore,it is essential to detect the cracks occurred in pipelines.The axial crack-like defects in elbows with different angle are inspected by using the T(0,1)mode guided waves,in which different configurations including 45°,90°,135°and 180°(straight pipe)are considered respectively.Firstly,the detection sensitivity for different defect location is experimentally investigated.After that,finite element simulation is used to explore the propagation behaviors of T(0,1)mode in different bend structures.Simulation and experiment results show that the crack in different areas of the elbow can affect the detection sensitivity.It can be found that the detection sensitivity of crack in the middle area of the elbow is higher compared to the extrados and intrados of the elbow.Finally,the mode conversion is also investigated when the T(0,1)crosses the bend,and the results show that bend is a key factor to the mode conversion phenomenon which presents between the T(0,1)mode and F(1,2)mode.
文摘EGR(Exhaust Gas Recycling)技术近几年已成为发动机节能、减排的一种核心技术,发动机的工况对于EGR波纹管的可靠性要求极为苛刻,而EGR波纹管的材质选择与波形设计是其可靠性的根本。通过选用材质分析与波形设计试验,结果表明:300系不锈钢优良的力学、耐蚀和加工等性能使其成为EGR波纹管材质的首选,这为EGR波纹管提供了高的可靠性与工艺性。EGR波纹管采用液压多波一次成型工艺具有管材壁厚减薄量小,成型尺寸稳定的优点。?形波比U形波管具有更好的拉伸、疲劳性能及应力分布状态。
