Structural Physical Parameter Identification of Nonlinear Parametric System in Time Domain

2011 ◽  
Vol 94-96 ◽  
pp. 1040-1043
Author(s):  
Xiang Jian Wang ◽  
Jie Cui
Keyword(s):  
Singular Value Decomposition ◽  
Parameter Identification ◽  
Physical Parameter ◽  
High Precision ◽  
Time Domain ◽  
Singular Value ◽  
Parametric System ◽  
Levenberg Marquardt ◽  
Shear Type ◽  
Value Decomposition

The modified Levenberg-Marquardt (mLM) method is introduced for nonlinear parametric system, such as stiffness proportional damping and Rayleigh proportional damping. Since the mLM method is sensitive to the initial values of parameter, a SVD-mLM method is proposed with combination of singular value decomposition (SVD). Parameter identification of five-storey shear-type is simulated with incomplete output. The results show that the identified parameters have high precision, and the proposed method is effective and robust on noise.

Physical Parameter Identification of Horizontal Layered Soil without Ground Motion of Bedrock

2011 ◽  
Vol 90-93 ◽  
pp. 1439-1442 ◽  
Author(s):  
Xiang Jian Wang ◽  
Jie Cui
Keyword(s):  
Parameter Identification ◽  
Physical Parameter ◽  
Ground Motion ◽  
Singular Value ◽  
Layered Soil ◽  
Inversion Algorithm ◽  
Soil Layers ◽  
Parametric System ◽  
Value Decomposition ◽  
And Inversion

For linear parametric system, like mass proportional damping case, physical parameter identification of horizontal layered soil and inversion of ground motion of bedrock are done by using the Least-squares-based hybrid inversion algorithm. For nonlinear parametric system, such as Rayleigh proportional damping case, the modified Levenberg-Marquardt (mLM) method is introduced. Since the mLM method is sensitive to the initial values of parameter, a SVD-mLM method is proposed with combination of singular value decomposition (SVD). Parameter identification of nonlinear parametric system and inversion of ground motion are performed by using the SVD-mLM-based hybrid inversion algorithm. The numerical simulation results show that the identified parameters of horizontal soil layers and inversed ground motion of bedrock have high precision, and the proposed method is useful for geotechnical engineering and robust on noise.

Research on Modal Parameter Identification of the Cable Stayed Bridges Based on the Singular Value Decomposition of the Power Spectrum

2012 ◽  
Vol 256-259 ◽  
pp. 1623-1626
Author(s):  
Hong Xia Xiong ◽  
Ci Feng Qin ◽  
Yang Jiang
Keyword(s):  
Singular Value Decomposition ◽  
Power Spectrum ◽  
Parameter Identification ◽  
Singular Value ◽  
Modal Parameter ◽  
Modal Parameter Identification ◽  
Element Computation ◽  
Modal Selection ◽  
Value Decomposition ◽  
Selection Of

In view of the modal parameter identification when only has the output signals of the system under ambient excitations has difficulty, a new method which can identify the structural modal parameters exactly based on singular value decomposition of the power spectrum is put forward. This method is used in the modal parameter identification of a cable stayed bridge under ambient excitations, and the identification frequency is compared with the finite element computation frequency. The results indicated that this method has overcome the subjectivity in modal selection of frequency domain pick-peaking method, choose eigenfrequency and identify close modal accurately and objectively. With the advantages of practical, processing simply and fast.

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