【摘要】 基于含缺陷结构断裂评定的COD设计曲线与净截面屈服失效判据,对2219铝合金搅拌摩擦焊结构进行了工程临界评定(ECA)。分析了2219铝合金搅拌摩擦焊接头焊核区、热机影响区、热影响区和母材区的临界裂纹尺寸,确定了不同载荷水平下2219铝合金搅拌摩擦焊结构的表面缺陷容限,并对特定内压下2219铝合金运载火箭贮箱筒段搅拌摩擦焊纵缝进行了ECA评定,为2219铝合金搅拌摩擦焊结构的断裂控制提供了参考。研究结果表明,纵向前进边热影响区为2219铝合金搅拌摩擦焊接头断裂控制的关键区域,特定内压条件下给定的表面缺陷可以接受。更多还原

【Abstract】 Based on the failure criteria including COD design curves and net section yield, engineering critical assessment(ECA) on 2219 aluminum alloy structure welded by friction stir welding(FSW) was carried out. Critical crack sizes of Nugget zone(NZ), thermo-mechanically affected zone(TMAZ), heat affected zone(HAZ) and base material(BM) of 2219 aluminum alloy FSW joint were calculated. The surface defect tolerances of friction-stir-welded 2219 aluminum alloy structure under different stress-level were obtained, and ECA on longitudinal FSW joint of launch vehicle tank under a certain pressure inside the cylinder was executed. ECA method in this study provides a reference for fracture control of friction-stir-welded aluminum alloy structure. Results show that HAZ at the longitudinal advancing side is the key area for the fracture control of the 2219 aluminum alloy FSW joint. The given surface defects are acceptable under specific internal pressure.更多还原