起竖装置作为火箭发射的关键装置，其起竖承载性能对火箭发射成功至关重要。针对某火箭起竖装置在起竖瞬间加载工况下出现的立板失稳现象，为分析立板失稳的原因，考虑起竖装置实际受载情况，建立起竖装置有限元仿真模型，对起竖瞬间工况下立板两侧的压力载荷进行提取，基于小挠度薄板弹性稳定理论，对立板局部失稳进行了解释：立板在起竖瞬间受压载荷超过了其临界失稳载荷，表现为横向弯曲变形失稳特征。根据分析结果提出立板局部补强措施，对补强后起竖装置开展有限元分析和起竖加载试验，结果表明：左、右立板对应测点应力一致性较好，测点仿真计算与试验测试结果偏差不大于10%，横向弯曲变形由补强前的5.3 mm减小到补强后的1.6 mm，证明了结构补强的有效性。相关结论为大型复杂结构局部稳定性分析提供了参考。

As a key device for rocket launch, the erecting device's load-bearing performance is crucial for the success. In response to the instability phenomenon of the vertical plate of a certain rocket erecting device under the loading condition at the moment of erection, in order to analyze the reasons for the instability of the vertical plate, a finite element simulation model of the erecting device was established considering the actual load situation. The compressive load on both sides of the vertical plate under the working condition of erection was extracted, and based on the theory of small deflection thin plate elastic stability, the local instability of the vertical plate was explained: the compressive load of the vertical plate at the moment of erection exceeded its critical instability load, manifested as the characteristic of lateral bending deformation instability. Based on the analysis results, local reinforcement measures for the vertical plate were proposed. Finite element analysis and erecting loading tests were conducted on the vertical device after reinforcement. The results indicate that the stress consistency at the corresponding measurement points of the left and right vertical plates is good, and the stress deviation between the simulation calculation and the test result is not more than 10%. The lateral bending deformation decreases from 5.3 mm before reinforcement to 1.6 mm after reinforcement, proving the effectiveness of structural reinforcement. The relevant conclusions provide a reference for the local stability analysis of large and complex structures.