ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2017, Vol. 38 ›› Issue (8): 221024-221024.

### Identification of spatial distribution of modulus field of composite material based on frequency response function

FAN Gang1,2, WU Shaoqing1,2, LI Yanbin3, FEI Qingguo1,2, HAN Xiaolin1,2

1. 1. Department of Engineering Mechanics, Southeast University, Nanjing 210096, China;
2. Jiangsu Key Laboratory of Engineering Mechanics, Nanjing 210096, China;
3. School of Mechanical Engineering, Southeast University, Nanjing 211189, China
• Received:2016-12-06 Revised:2016-12-27 Online:2017-08-15 Published:2017-03-15
• Supported by:

National Natural Science Foundation of China (11402052,11572086);Program for New Century Excellent Talents in University (NCET-11-0086);Natural Science Foundation of Jiangsu Province of China (BK20140616)

Abstract:

Considering the heterogeneity of the macroscopic mechanical properties of fiber braided composites, an identification method for spatial distribution of elastic modulus field of the composite beam structure based on Frequency Response Function (FRF) is proposed. The optimization problem is constructed based on sensitivity analysis. The minimum norm of the difference between the measured and the calculated frequency response of acceleration is taken as the objective function, and the spatial distribution of the elastic modulus of the composite beam is then identified by iterative methods. Numerical simulation of a cantilever beam is conducted to verify the correctness of the identification method, and the modal test is then carried out. The homogeneous elastic modulus obtained from a three-point bending test of the same composite beam is taken as the initial value of the optimization problem. The non-contact measurement approach is adopted to obtain the dynamic displacement response of each measuring point on the beam in the modal test, and the acceleration frequency response function is calculated as input data. Results show that the frequency response functions of each measuring point on the beam calculated by the identified elastic modulus field agree well with the experimental values, and the proposed method is feasible when the measurement dynamic responses are noise contaminated. This method is capable of providing a more accurate elastic modulus field for equivalent modeling of composite materials.

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