Modeling and Finite Element Analysis of Load-Carrying Performance of a Wind Turbine Considering the Influence of Assembly Factors

Abstract

Abstract:In this work, a wind turbine shrink disk is used as the research object to investigate load-carrying performance of a multi-layer interference fit, and the theoretical model and finite element model are constructed. According to those models, a MW-level turbine shrink disk is designed, and a test device is developed to apply torque to this turbine shrink disk by hydraulic jack. Then, the circumferential slip between the contact surfaces is monitored and the slip of all contact surfaces is zero. This conclusion verifies the reasonability of the proposed models. The effect of the key influencing factors, such as machining deviation, assembly clearance and propel stroke, were analyzed. The contact pressure and load torque of the mating surfaces were obtained by building typical models with different parameters using finite element analysis (FEA). The results show that the minimum assembly clearance and the machining deviation within the machining range have little influence on load-carrying performance of multi-layer interference fit, while having a greater influence on the maximum assembly clearance and the propel stroke. The results also show that the load-carrying performance of a multiple-layer interference fit can be ensured only if the key factors are set within a reasonable design range. To avoid the abnormal operation of equipment caused by insufficient load torque, the propel stroke during practical assembly should be at least 0.95 times the designed propel stroke, which is significant in guiding the design and assembly of the multi-layer interference fit.

Multiobjective Intelligent Cooperative Design for the Multilayer Interference Fit

“…cannot exceed the material yield limit Q, the minimum contact pressure p 1,min must be greater than the pressure required to transmit the rated torque, and d 3 min , d 2,4 , and δ 3 max meet the upper and lower limit requirements. According to design experience [9,10], E max and p 1,min need to be as large as possible; that is, the negative number of its objective function − f 1 (x) and − f 2 (x) need to be as small as possible, and at the same time, f 3 (x) is as small as possible to reduce the mass of the shrink disk and lower the manufacturing cost. e priority of the above three functions is as follows:…”

“…Considering the structural symmetry of the shrink disk, in order to reduce the calculation cost, the two-dimensional axisymmetric reduced integral element CAX4R is selected as the finite element model cell type [22,23]. e total number of units is 7828. e mesh of the model is divided into a quadrilateral, and the mesh sizes of the outer ring, inner ring, sleeve, and shaft are 4 mm, 2 mm, 4 mm, and 4 mm, respectively [9]. e layout seeds are determined by the length of edges, which optimizes the aspect ratio of the mesh and improves the mesh quality.…”

“…Most of the above research was aimed at single-layer interference fit, but with the actual needs of engineering, many use double or multilayer interference fit structure to achieve load transfer. Wang et al [8][9][10] deduced the mechanical model of the multilayer interference fit, analyzed its bearing capacity by the finite element method, and proposed a reliable and robust design method. Qiu and Zhou [11] investigated the temperature effect of the multilayer interference fit.…”

Contact Pressure Algorithm of Multi-Layer Interference Fit Considering Centrifugal Force and Temperature Gradient

“…According to the Equations (15) and (16), the contact pressure of each contact surface of multi-layer interference cylinder is influenced by temperature of inner and outer surfaces. In Figure 6, the influence of temperature gradient on the contact pressure of multi-layer cylinder is analyzed by applying the temperature on inner and outer surfaces, then the matrix model is verified by comparing the numerical solution with the analytical solution.…”

“…However, the research on the influencing factors of interference fit is mainly concentrated in a single layer. Currently, multi-layer interference fit is widely used in engineering, for example low-speed coupling of wind turbine (Figure 1), which can be used as the typical application of multi-layer interference cylinder [16]. Here, the effects of centrifugal force and temperature gradient on the contact pressure of multi-layer interference cylinder are analyzed.…”