板状燃料组件非线性振动特性

设计1个能模拟堆芯燃料组件工作环境和力学边界条件的台架,研究板状燃料组件的非线性振动行为。对安装在振动台上的系统进行白噪声随机激励,得到燃料组件响应-激励关系不同方向、不同介质、不同振级共42种工况的系列曲线。试验结果表明:随着激励振级加大,板状燃料组件的第一阶共振频率减小;板状燃料组件在水中的第一阶共振频率远比在空气中的小,且非线性特性仍呈软弹簧特性;板状燃料组件在环境中的振动阻尼大,能大大抑制抗震响应。

Nonlinear Vibrational Characteristic of a Parallel Plate Fuel Assembly

A tank to simulate a fuel assembly's environment and mechanical boundary condition is designed.In aseismatic reactor core test,the nonlinear vibrational behavior of the fuel assembly is studied.The system which was installed in vibration table under 42 environments was excited by white noise,and a series of curves about relationship between fuel assembly's response and excitation under different direction,different medium,different excitation magnitude were obtained.As excitation magnitude increases,the 1st resonant frequency of the parallel plate fuel assembly decreases.Compared with that in air,the 1st resonant frequency of the parallel plate fuel assembly in water decreases greatly,and the nonlinear vibrational characteristic is soft spring.On the other hand,the damp of fuel assembly in water increases greatly and restrains the aseismatic response greatly.