Monotonic four-point bending tests were conducted using pipe specimens having orifice undergoing local wall thinning. The effects of local wall thinning on the fracture behaviors of pipe were investigated. Local wall thinning was machined on the inside of pipes in order to simulate erosion/corrosion metal loss. The configurations of the eroded area were l=100 mm in eroded axial length, d/t=0.5 and 0.8 in eroded ratio, and 2θ=180° in eroded angle. The area undergoing local wall thinning was subjected to either tensile or compressive stress. Failure type could be classified into ovalization, local buckling, and crack initiation, depending on eroded ratio, and stress at the eroded area. Three-dimensional elasto-plastic analyses were also carried out using the finite element method, which is able to accurately simulate fracture behaviors. The crack initiation point could be successfully predicted by the criterion proposed by Miyazaki et al.
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机译：使用具有在局部壁稀化的管道进行孔的管样品进行单调四点弯曲试验。研究了局部壁稀土对管道断裂行为的影响。在管道内部加工局部壁变薄，以模拟侵蚀/腐蚀金属损失。腐蚀区域的腐蚀轴向长度的腐蚀区域的构造是侵蚀的轴向长度，d / t = 0.5和0.8以腐蚀的比例，并且蚀刻角度为2θ= 180°。经受局部壁变薄的区域进行拉伸或压缩应力。故障类型可分为椭圆化，局部屈曲和裂纹启动，这取决于腐蚀的比率，以及侵蚀区域的应力。还使用有限元方法进行三维弹性塑料分析，能够精确地模拟断裂行为。可以通过Miyazaki等人提出的标准来成功预测裂缝启动点。
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