【摘要】 本文提出一个平板和内压容器表面裂纹SCOD的简便计算方法。进行了平板及内压圆筒外壁的SCOD测定试验。计算值与实测值间偏差在±10％以内;并与文献中三维断裂力学迭代法的数值结果作了比较讨论。SCOD计算式可应用于平板或压力容器、管道中表面裂纹深度的测算,也可用于裂纹深度方向扩展速率的在役监控以及研究表面裂纹疲劳扩展中形状变化规律的新手段。文中对上述应用的试验方法作了介绍。更多还原

【Abstract】 This paper presents a simple method to estimate surface crack opening displacement (SCOD) of tension specimens and pressurized vessels. To date, the only procedure for estimating SCOD is introduced by A. S. Kobayashi.In order to examine the proposed method experiments have been done on crack growth and fracture in plate specimens and cylinders Good agreement between predicted and experimental results has been obtained as shown by curves of normalized SCOD versus normalized depth of crack.One of the applications of SCOD equation is to evaluate the depth of surface crack in plates or vessels. A procedure for estimating crack depth is presented. SCOD equation can also be used to monitor crack growth in pressurized vessels and pipings. Inthis paper, a new experimental procedure for evaluating crack growth da/dN and △Kt wi-thout any mechanical or thermal moving on the tip of crack has been developed.The measuring technique of SCOD in flawed tension plates and cylinders is explained in drtail. Strain gauges and displacement gauges are satisfactorily used to measure and record SCOD periodically or continually during the fatigue tests.For checking the calculated depths of surface cracks, "Growth Rings" on the fracture face of specimens and cylinders are marked by changing cyclic load levels and heat strainings, shown in accompanging photos.更多还原