铸铁三点弯曲切口梁的抗断裂性能

ANTI-FRACTURE PERFORMANCE OF THREE-POINT BENDING CAST IRON BEAM WITH NOTCH

铸铁类材料裂纹端部的断裂损伤过程区能简化为具有黏聚力的裂纹。为探寻带切口铸铁试件的最大承载力计算方法,用实验机对8种不同切口尺寸的铸铁三点弯曲梁进行加载实验,得到载荷随加载点位移变化曲线;计算各个试件断裂过程消耗功以及相应单位断裂面消耗比能。分别通过实验测得载荷和预制裂纹尺寸及等效裂纹长度,计算应力强度因子和能量释放率。根据黏聚裂纹应力强度因子计算式与双K断裂准则,得到该类材料结构承载力的理论计算数值;并与实验结果进行对比,两者符合良好。

The fracture damage process zone of the cast iron can be simplified as a crack with adhesive force.In order to investigate the bearing capacity calculation method of cast iron notched beams,the three-point bending experiments of 8 sized notch specimens were carried out.The curves of load with displacement of loading point were obtained in the experimental procedure.Accord to these curves,waste work and fracture specific energy were calculated.Also the stress intensity factors of each specimen were calculate...