Session: 36-07 Multi-Disciplinary and Collaborative Optimization applications (1)

Paper Number: 128970

128970 - Frequency Topology Optimization of Fan Blade Considering Stress Stiffening and Spin Softening 

Fan blades are prone to dynamic failures due to periodic loads The optimization design of hollow fan blades ensures the stable operation of aircraft engines. The blades are subjected to harsh periodic aerodynamic loads for a long time, and frequency optimization design can prevent vibration failure problems. Due to requirements such as aerodynamics, bearing, and bird-strike, the outer surface and reinforcement configuration of hollow fan blades are basically determined. Topology optimization design has a greater ability and design space compared to shape and parameter optimization, which can effectively expand the frequency adjustment range and is widely used in blade design. The most commonly used method in engineering is to increase the thickness of blades to increase their stiffness and vibration frequency (Rahmati et al. 2015). Topological optimization methods often achieve frequency optimization of hollow fan blades through reinforcement design (Meng et al.  2015). However, topology optimization design cannot preserve the original structural topology, resulting in multiple performance requirements must being optimized together, such as static strength and bird-strike. The optimization requirements are complex and it is difficult to build the optimization framework. Meanwhile, the stress stiffening and spin softening effects of blade fans caused by high rotational speeds cannot be ignored, and existing topology optimization frameworks cannot accurately consider them. This article proposes a topology optimization method based on the initial structural skeleton, which achieves small frequency regulation without affecting other performance of the blade through corrosion and expansion. A blade frequency topology optimization framework was established that considers both stress stiffening and spin softening, and the effects of the pseudodensity on the stress stiffness matrix and spin softening matrix are taken into account. The sensitivity of blade frequency is derived through the adjoint method. Based on this optimization framework, a universal topology optimization process has been established, which can construct a multi condition topology optimization column for blade fans frequency to avoid the rotational frequency. This optimization process utilizes the minimax multi-objective optimization strategy to construct optimization constraints that avoid hazardous frequencies, ensuring the reliability of the structure under multiple working conditions. This article takes the engineering example of hollow fan blades as an example to carry out frequency topology optimization design and verify the effectiveness of the optimization framework.

Presenting Author: Mingzhou Wang Dalian University of Technology

Presenting Author Biography: Dr. Mingzhou Wang is currently pursuing the School of Energy and Power at Dalian University of Technology, with a main research focus on the multidisciplinary analysis and optimization of aeroengine structures

Authors:

Shenli Xu Dalian University of Technology
Mingzhou Wang Dalian University of Technology
Lizhong Mu Dalian University of Technology
Yan Zhou NingBo Institute of Dalian University of Technology