| Earthquake is one of the most dangerous natural disasters to the safety of nuclear power plants.Pipeline valve system,as an important part of the pressure boundary of nuclear power plants,needs to ensure its structural integrity and operability during earthquakes.At present,the test method is usually used to evaluate the operability of pipeline valve system in engineering,but the test method cannot evaluate the design process and the equipment that has been put into use,and there is no recognized standard and process for evaluating the operability of equipment by numerical simulation.Virtual prototype technology is a branch of numerical simulation applied to the analysis of the dynamic characteristics of multi-body systems,which can clearly analyze the dynamic characteristics of typical multi-body systems such as pipeline valve system.However,the reliability and method of pipeline valve system operation under seismic load analysis by virtual prototype technology have yet to be studied.Therefore,according to the actual design of the valve pipe system vibration table test,the high-speed photography system is used to measure the vibration response of the components.Then the virtual prototype which accurately reflects the vibration response of the test structure is established according to the test results.Finally,the vibration simulation test of the virtual prototype is carried out and its operability is analyzed.The main conclusions of the paper are as follows:1.In measuring the vibration response of valve and pipeline system in shaking table test,because the accuracy of data measured by high-speed camera system is low under the condition of long distance and long span,the traditional measurement method of high-speed camera system is optimized according to the actual situation,and the processing method of optimized measured data combined with image processing technology is put forward.The data optimized by this method meet the precision and accuracy requirements of vibration response measurement,which provides a reference for vibration response measurement of shaking table.2.A method to determine the value of rigid constraints at both ends of pipeline valve system testing is proposed by combining modal analysis theory with sensitivity analysis.The numerical simulation model optimized by this method is similar to the mode and vibration response measured by the experiment,which reduces the influence of numerical simulation model on randomness in manufacturing and installation,and improves the accuracy of numerical simulation.3.The virtual prototype technology can be used to analyze the operability of valve pipeline system under seismic load,which can provide reference for the operation analysis of the pipeline valve system.The results show that when the peak value of vibration excitation is greater than or equal to 2g,the valve emergency closing time and valve body stress of the test valve do not meet the standard requirements.When the peak value of vibration excitation is less than 6g,the stress and deformation of valve stem meet the standard requirements.Therefore,optimizing the emergency closing time of the valve and the design of the valve body structure are the main aspects to improve the seismic performance of the valve. |
