铝/铝-镁合金层合板疲劳性能研究

为同时满足承载和防腐蚀两个要求,铁路浓硝酸罐车罐体选用铝/铝镁合金层合板复合材料,纯铝为其内胆材料,铝镁合金为承载材料。现对上述层合板材料试样进行疲劳性能试验以及弹塑性分析,发现随着外载的增加,由于层合板两种材料变形不协调,界面产生应力集中从而造成界面开裂,裂纹向纯铝层扩展,纯铝层断裂,最终导致层合板断裂。据此,建立了层合板材料的名义应力—寿命曲线和局部应变—寿命曲线,为浓硝酸罐车罐体的疲劳设计提供重要依据。

Fatigue Performance Study on Aluminum/Aluminum-Magnesium Alloy Laminated Plate

The tank body material of rail tanks for concentrated nitric acid is aluminum/aluminum magnesium alloy laminated plate to satisfy both requirements of anti corrosion and force bearing. Aluminum is the inner material and aluminum-magnesium alloy is the load bearing material. In this paper, fatigue test and elastic-plastic analysis for above laminated plate specimens were taken to further study the material mechanical properties. We found that as the load increases, the deformation of the two kinds of materials is inharmonious, which leads to stress concentration and interracial crack. Then the crack expands to the aluminum layer and makes the fracture of the laminated plate eventually. The nominal stress-life curve and local strain-life curve of the laminated plate material are established which will provide important reference for the tank fatigue design of rail tanks for concentrated nitric acid.