Optimal Sensor Placement For Vibration Tests In Hydropower House

Proper pretest planning is a vital component of any successful vibration test. An extremely important part of the pretest exercise is the placement of sensors. Powerhouse structure is complex and its dynamic loads are difficult to simulate exactly, which cause the vibration characteristic being very complex. In order to acquire more reliable vibration characteristic information, optimal sensor placement is very important. Also the cost of sensor is expensive and it is impossible to use too many sensors in a vibration test. So how many sensors to use is a practical problem. What is more important is that sensor placement for vibration tests in hydropower house is used to be allocated based on experience.And it is the first time to introduce the optimal sensor placement theory and method to the vibration tests in hydropower house.So it is not only important but also necessary. The purpose of this paper is to research the optimal sensor placement for vibration tests in hydropower house in order to acquire more reliable information of the structure vibration characteristic and the dynamic load characteristic.This paper mainly studies two methods of optimal sensor placement in civil engineering often used. The first is using BDA method based on signal subspace correlation techniques and the second is model assurance criterion based on main column decompose using QR method. Firstly, this paper introduces the realize process of optimal sensor placement in a plane frame structure with model analysis result using finite element software ANSYS. Though comparing both merit and shortcoming in theory and practical apply, the second method is superior to the first one in result of load identification. What important is that the second method can provide the feasible number of sensor. So finally the second method is chosen. Considering that the complexity of the powerhouse structure and vibration characteristic, this paper discuss the effecting of model creation to optimal sensor placement using the 12th hydrogenerator units of third phase powerhouse and put forward some significative advice. Also study some different optimal sensor placement on different analysis purpose.Though analyzing of the optimal result, theory is correct and the method is easy to realize. It not only provides theory foundation but also brings convenience and shortcut realizing method, which has some practical applying value.