Data based stochastic subspace identification for structural strain modal parameter

作者：Xiao Xiang^*; Ren Wei Xin; Dai En Bin

来源：Journal of Central South University(Science and Technology), 2012, 43(9): 3601-3608.

• Ambient excitation
• Data-based method
• High noise levels
• Identification method
• Local damage
• Modal parameter identification
• Modal parameters
• Numerical example
• Real structure
• State variables
• State-space models
• Stochastic subspace
• Stochastic subspace identification
• Strain change
• Strain model
• Structural strain
• Theory model

Based on the stochastic state-space model with strains and strain change rates as state variables, the data based stochastic subspace method for strain modal parameter identification was established like the one with displacement modal parameter identification, which can be used in the strain modal parameter identification for the structure under ambient excitation. A numerical-simulation and an experimented example were used to verify the identification method. The results of numerical example show that the strain models identified by the method proposed in this work are in good agreement with the theory models, and is very sensitive to local damage of the structure even with high noise level, therefore, it can be used in health monitor successfully for real structures. The identified strain model of experimented example agrees well with the theory model, which further demonstrates the practicability of the proposed method.

• 出版日期2012
• 单位中南大学