桥式起重机焊接箱形梁疲劳裂纹与剩余寿命的研究

以桥式起重机焊接箱形梁为研究对象,运用断裂力学,对强度因子和疲劳裂纹扩展公式加以修正,研究了在恒幅与随机变幅载荷作用下线弹性裂纹的扩展情况,以及材料在小范围屈服的情况下弹塑性裂纹的扩展情况。该研究与实际情况更加接近,能够相对准确地估算出桥式起重机的剩余寿命,对于减少起重机疲劳破坏事故的发生,指导起重机的设计、制造和特种设备的检验分析具有重要意义。

Studies on fatigue crack and remaining life of welding box girder of bridge crane

Taking the welding box girder of the bridge crane as the study object,through using the fracture mechanics to correct the intensity factor and the fatigue crack growth equation,this paper studies the growth conditions of the linear elastic crack under the loading of constant amplitude and random fluctuated amplitude,as well as the growth conditions of the elastic-plastic crack when the material is under the yielding condition of small range. Due to the study＇s closer to the actual conditions,the remaining life of the bridge crane could be estimated more precise. This study has significant meaning for reducing the occurrence of the fatigue damage incident of crane,and guiding the design and manufacture of the crane as well as the inspection and analysis of the special equipment.