基于有限元法分析的机架装配干涉处理

Rack Assembly Interference Processing based on Finite Element Method Analysis

针对某汽轮发电机组总装时出现发电机端盖压板螺母与机架上横板干涉的问题,提出了对横板进行部分切割的解决方案。采用有限元法对机架切割前后的应力、应变及固有频率进行计算。计算结果显示:在横板切割前后,机架上的应力和应变量变化极小,最大应力及应变均位于发电机的安装位置处,其应力水平远低于材料的许用强度,变形量也完全可以满足刚度要求。机架的前10阶固有频率在横板切割前后变化很小,虽然机架第33阶频率变化为1%,但是其频率相对各工频及其倍频均有较大的安全裕度。根据计算结果,认定切割横板不会对机组振动造成影响。现场对该板进行了切割,经试验验证,机组运行平稳,各项振动指标符合要求。

Aiming at the problem of interference between the pressure plate nut of the generator end cover and the horizontal plate on the frame during the final assembly of a turbo-generator set,a solution for partially cutting the horizontal plate was proposed.The finite element method is used to calculate the stress,strain and natural frequency of the frame before and after cutting.The calculation result shows that before and after cutting the horizontal plate,the stress and strain on the frame change very little,the maximum stress and strain are located at the installation position of the generator,the stress level is far lower than the allowable strength of the material,and the deformation can fully meet the rigidity.Claim.The first tenth order natural frequency of the rack changes little before and after the cutting of the horizontal plate.Although the 33rd order frequency of the rack changes to 1%,its frequency has a relatively large safety margin relative to each power frequency and its multiplier.According to the calculation results,it is determined that cutting the horizontal plate will not affect the vibration of the unit.The board was cut on the spot,and the test proved that the unit was running smoothly and the various vibration indicators met the requirements.