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以高温主蒸汽管线为例,应用有限元方法分析了大型高温管系在实际工况下的应力情况、蠕变损伤特点以及基于振动特性的损伤识别.以典型弯管为例,分析了在不同损伤情况下高温管道的振动模态变化特性.结果表明:在微小损伤的条件下,高温直管/弯管的频率变化较小,考虑到实际测量噪声的影响,单纯从结构的固有频率变化来识别微小的损伤是比较困难的;通过分析冲击响应的变化可以判断是否已经出现损伤,尤其是在损伤大于30%时,弯管对冲击响应的变化非常明显.
Taking the high temperature main steam pipeline as an example, the stress situation, creep damage characteristics and damage identification based on vibration characteristics of large-scale high-temperature pipelines were analyzed by using finite element method. Taking a typical elbow as an example, The results show that under the condition of slight damage, the frequency change of straight pipe / elbow at high temperature is small. Considering the influence of actual measurement noise, the change of natural frequency of the structure Identifying minor injuries is more difficult; judging whether an injury has occurred or not is possible by analyzing changes in the impact response, especially when the damage is greater than 30%.