Development of inspection techniques for non-sharp defects

断裂力学假设存在尖锐的裂纹。对于诸如孔隙、机械或腐蚀损伤、焊接缺陷或某些设计特征（包括部分熔透焊缝中的裂缝）等真实的缺陷，该方法是保守的，有时过于保守。这些缺陷具有非尖锐的缺陷尖端，与含有尖锐裂纹的等效部件相比，其抗断裂性增加。为了在工作部件中利用这种增加的韧性，有必要测量半径。这构成了一个重大挑战，因为目前无法区分尖锐（例如疲劳）裂纹和非尖锐缺陷，并产生准确的形状描述。最近的发展表明，创造新的能力，提高安全关键资产的结构效率，是有希望的机会。这些方法是在布里斯托大学（UoB）开创的，尚未被开发用于设计和结构完整性应用，因此需要进一步的实验测试和验证。

The science of fracture mechanics assume a sharp crack is present. This approach is conservative, sometimes overly so, for real defects such as porosity, mechanical or corrosion damage, weld defects, or certain design features including crevices in partial penetration welds. These defects have non-sharp defect tips and an increased resistance to fracture compared to an equivalent component containing a sharp crack.To take advantage of this increased toughness in operating components it is necessary to measure the radius. This poses a significant challenge as it is not currently possible to distinguish between sharp (e.g. fatigue) cracks and non-sharp defects and to produce accurate shape descriptions. Recent developments show promising opportunities for creating new capabilities for improved structural efficiency of safety-critical assets. These methods were pioneered at the University of Bristol (UoB) and have yet to be exploited for design and structural integrity applications and therefore further experimental testing and validation is required.