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本文叙述由汽轮机围带扭叶片组各类计算振型、按能量守恒原理进一步算得在发生各类振型的共振时叶片组叶身、叶根、围带及铆钉的振动应力。并根据材料的许用耐振强度判断其共振的安全性。本法主要用来计算电厂汽轮机中等长度的叶片。这里也计算了曾发生五次振动断裂的法国进口机组第一级动叶,计算结果表明该级原先叶片主要是由于2nZ喷咀激振力引起的叶片组轴向弯曲U型共振断裂。经法国修改设计后,仍旧断裂,但断于nZ喷咀激振力引起的叶片组切向弯曲B_o型共振。计算结论与实际事故部位及断口分析符合。
In this paper, the types of vibration modes calculated by turbine shrouded blade set are described. According to the principle of conservation of energy, the vibration stress of the blade body, root, shroud and rivet in the blade group is further calculated. And according to the allowable vibration strength of the material to determine the safety of its resonance. This method is mainly used to calculate the turbine blades of medium length. Here, the first-stage buckets of french imported units that have vibrated five times have also been calculated. The calculation results show that the original vanes of this stage are mainly caused by the axial bending U-shaped resonance fracture of the blade groups caused by the exciting force of 2nZ nozzles. After the modification of the design in France, it still fractured, but broken in the nZ nozzle excitation force caused by the blade group tangential bending B_o resonance. The calculated conclusion is consistent with the actual accident site and fracture analysis.