起重机自重应力对安全评估中应力测试实验结果的影响

应力测试是起重机安全评估中必须进行的一项检测。目前在安全评估工作中常采用应变电测法来采集起重机工作过程中的应力时程数据,由于该方法只能采集到结构由于载荷变化产生的应力,而无法采集到结构因自重产生的应力,导致应力测试无法获取结构的完整应力。利用起重机金属结构自重应力在总应力中占有的权重,分析其对应力测试实验结果的影响大小,试验结果表明在危险截面自重应力大小占总应力大小可达60%,此时不考虑自重应力进行结构安全性的判定是不全面的。可考虑利用仿真技术获取自重应力^[1,2],从而使得安全评估应力测试实验结论更加准确。

Influence of self-weight stress of cranes on stress test results in safety assessment

Stress test is a necessary test item in crane safety evaluation.Currently,in the safety assessment work,the electromotive strain method is usually used to collect the stress time history data of cranes in working.Because this method can only collect the stress generated due to the load change on the structure,can not collect stress generated due to the self-weight on the structure,so it is impossible to obtain all the structural stress in the stress test.Based on the proportion of the self-weight stress of metal structures of cranes in the total stress,the analysis of the influence of the self-weight stress on the stress test results is carried out.Test results show that when the self-weight stress of a dangerous section reaches 60%of the total stress,the assessment results of structure safety without considering the self-weight stress are incomplete.One can consider using simulation technology to obtain selfweight stress[1,2],so as to obtain more accurate conclusions in safety assessment stress tests.