拉伸载荷下含缺陷管道宽板力学响应与断裂失效试验

Mechanical response and fracture failure test of wide plate with defective pipe under tensile loading

为探究缺陷与焊缝的相对距离和夹角对X65螺旋埋弧焊钢管失效的影响,开展宽板拉伸试验,采用三维数字图像相关法分析轴向拉伸载荷下缺陷到焊缝的距离、缺陷与焊缝的夹角对管道宽板的力学响应和断裂失效行为的影响特征.结果表明:焊缝和缺陷的存在,以及缺陷到焊缝的相对距离和夹角对管道宽板的应变变化和断裂失效行为有影响,且不同的相对距离和夹角对其抗拉强度、应变分布和断裂失效行为的影响程度不同;当缺陷与焊缝的夹角为30°且当缺陷到焊缝的距离为39 mm时,管道宽板的抗拉强度最低、裂纹萌生及断裂失效所需位移载荷最小,此时其承载能力最差,最容易断裂失效.

In order to investigate the influence of the relative distance and angle between defects and welds on the failure of X65 spiral submerged arc welded steel pipe,wide-plate tensile tests are carried out,and the influence of the distance from defects to welds and the angle between defects and welds on the mechanical response and fracture failure behavior of the wide-plate pipeline are analyzed by using the three-dimensional digital image correlation method in axial tensile loading.The results show that the existence of weld and defects as well as the relative distance and angle from the defects to the weld have an effect on the strain change and fracture failure behavior of the pipe wide plate,and different relative distances and angles have different degrees of influence on its tensile strength,strain distribution and fracture failure behavior,and the tensile strength of the pipe wide plate is the lowest,the crack is the lowest and the fracture failure behavior is the lowest when the angle between the defects and the weld is 30°and the distance between the defects and the weld is 39 mm.The lowest tensile strength,crack sprouting and fracture failure requires the smallest displacement load,at this time its bearing capacity is the worst,the most likely to fracture failure.