Dynamic Characteristics And Vibration Analysis For Ground Hydropower House

With the rapid development of hydropower in China, the unit capacity of hydropower plant has gradually expanded, resulting in the structure of power station more complicated, and the size more augmented. These changes will inevitably weaken the rigidity of the plant and unit capacity. For hydropower plant, the unit is the core part. The unit’s complex vibration accompanied by huge energy easily induced the vibration of powerhouse structure.Accordingly, it becomes very important that carrying out large-scale hydropower projects into comparative analysis and grasping the characteristics of structure various dynamic load performance. This provides effective and reliable reference and guiding principles for the hydropower plant design. In view of this problem, on the basis of establishing correct dynamic model, combined with the structure’s natural vibration characteristics, this paper focuses on the vibration of structure under the unit dynamic load. It analyzes the production of the vibration itself and the impact of vibration on the structure of other parts of the plant, thus providing correct modeling ideas and proper analysis method for the powerhouse vibration simulation later. The vibration of powerhouse structure design and reliable opinion is given. At the same time reliable advice is given for the anti-vibration design of the plant structure.Following are the main contents:(1) Optimize the existing vibration analysis numerical model, and establish a more reasonable numerical model, and select reasonable kinetic parameters, unify the boundary condition of simulation. Through the establishment of different dynamic model, the paper analyzed the structure of the natural vibration characteristics and dynamic response, and confirmed the material parameters in the modeling process, such as elastic modulus, damping ratio and poisson’s ratio. Also the appropriate range bedrock was analyzed. The paper as well as discussed the influence of water for the analysis of different types and different parts.(2) Discussion of pressure pulsation applying manner on the powerhouse structure and the sensitivity analysis was conducted. The paper analyzed the dynamic response of the structure under the pressure fluctuating load. The load was applied at the two ways. One is that dividing the runner into the volute, guide vane wheel, tail pipe three partitions, and taking fluctuating pressure data of the three measuring points. The other one is that the partition was conducted based on all measuring points. For the calculation results of the two programs, the dynamic response of structures was extracted for key parts. Based on this, appropriate and reliable applying manner was explored of the pulsating pressure, at the same time which site is the main effect of fluctuating load was determined.(3) The last is the vibration of powerhouse structure design. For the ground workshop upper structure, different structure forms were established, such as pillar, column-shear wall and solid wall. Analyze the structure from natural vibration, unit vibration and seismic aspects to determine appropriate upper structure. At the same time, the influence for the same analysis type of different forms of floor slab structure was carried out. Forms of floor slab can be plate and plate girder structure. By studying the various forms of structure, determine its own rules under the dynamic response, determine its sensitivity, thus put forward favorable structural form and design ideas of resistance for induced vibration by unit.