核级截止阀气动执行机构支架地震试验开裂原因剖析

Analysis of Cracking Causes of Nuclear Grade Stop Valve Pneumatic Actuator During Seismic Test

本文针对某型核级截止阀抗震鉴定试验过程中出现支架裂纹的情况,从弹簧、活塞实体、气动附件、试验工装等方面进行了原因剖析,并对该型截止阀进行了结构优化,最后采用静力法对优化后的截止阀进行了应力分析并通过了试验验证。结果表明,弹簧、活塞实体会较大程度降低阀门的固有频率,进而影响后续抗震试验及实际应用中的地震放大系数;增大支架结构圆弧拐角处的弧度可有效降低气动执行机构带来的应力集中。论文分析结果为该类核级气动截止阀抗震计算、结构设计及抗震鉴定试验的实施提供了参考。

This article analyzed the causes of bracket cracks during the seismic qualification test of a nuclear grade stop valve from the aspects of springs,piston entities,pneumatic accessories,and test tooling,and optimized the structure of the stop valve.Finally,the static method is used to analyze the stress of the optimized stop valve,which has passed the test verification.The results indicated that the spring and piston entities will significantly reduce the natural frequency of the valve,thereby affecting the seismic amplification coefficient in subsequent seismic tests and practical applications.Increasing the curvature at the arc corner of the support structure can effectively reduce stress concentration caused by pneumatic actuators.The analysis results provide a reference for the seismic calculation,structural design,and seismic evaluation test implementation of this type of nuclear grade pneumatic globe valve.