Innovative substructure approach to estimating structural parameters of shear structures

2018 ◽  
Vol 25 (4) ◽  
pp. e2139 ◽  
Author(s):  
Lijun Xie ◽  
Akira Mita ◽  
Longxi Luo ◽  
Maria Q. Feng
Keyword(s):  
Structural Parameters ◽  
Shear Structures ◽  
Substructure Approach

Application of the EKE and LSE-UI Based Substructure Approach for Damage Detection with Limited Output Measurements

2011 ◽  
Vol 255-260 ◽  
pp. 4171-4175
Author(s):  
Ying Lei ◽  
Chao Liu
Keyword(s):  
Damage Detection ◽  
Least Squares ◽  
Structural Damage ◽  
Structural Parameters ◽  
Least Squares Estimation ◽  
Complex Case ◽  
Benchmark Problem ◽  
Unknown Inputs ◽  
Limited Output ◽  
Substructure Approach

This paper presents an effort to apply the EKE (extended Kalman estimator) and LSE-UI (least squares estimation for unknown input) technique to detect structures damage with limited output measurements. This technique can be extended to detect structural local damage in complex structures based on substructure approach. Structural parameters and the unknown inputs are identified by a recursive algorithm based on sequential application of the extended Kalman estimator for the extended state vector and the least squares estimation for the unknown inputs. Only a limited number of measured acceleration responses of the benchmark structure subject to unmeasured excitation inputs are utilized. This structural damage detection method is applied to the ASCE SHM benchmark building to test its efficacy and provide a solution to the complex case of the Phase I benchmark problem. Damage detection results indicate that the proposed technique can detect and localize structural damage of the complex benchmark problem with good accuracy.

Estimation of structural parameters in time domain: A substructure approach

1991 ◽  
Vol 20 (8) ◽  
pp. 787-801 ◽  
Author(s):  
Chan Ghee Koh ◽  
Lin Ming See ◽  
Thambirajah Balendra
Keyword(s):  
Time Domain ◽  
Structural Parameters ◽  
Substructure Approach

Multi-taper method based substructure identification for shear structures

2020 ◽  
Vol 26 (15-16) ◽  
pp. 1266-1275
Author(s):  
Dongyu Zhang ◽  
Yong Huang ◽  
Ruifeng Li ◽  
Hui Li
Keyword(s):  
Structural Parameters ◽  
Identification Accuracy ◽  
Key Factors ◽  
Shake Table Tests ◽  
Application Range ◽  
Shear Structures ◽  
Numerical Studies ◽  
Structural Responses ◽  
Shear Structure ◽  
Substructure Identification

Quickly and accurately identifying structural status after natural disasters plays crucial roles in disaster rescue. Previously, the authors developed a substructure identification method for shear structures, which uses the frequency responses of short structural acceleration responses to estimate structural parameters inductively. However, the numerical studies found that the method could only provide moderately accurate results. In this paper, a thorough uncertainty analysis is performed to reveal the key factors that influence its identification accuracy. Based on these results, a new substructure method is proposed herein, which utilizes the cross power spectrum densities of structural responses, estimated by the multi-taper method, to formulate substructure identification problems. The error analysis is also conducted for the multi-taper method based method, explaining why this method can significantly improve identification accuracy, compared with the frequency response based method. Moreover, although the multi-taper method based method is originally derived based on stationary structural responses, a further analysis shows that it can be extended to non-stationary responses, greatly broadening the method’s application range. Finally, the simulation study of a 20-story shear structure and the shake table tests on a three-story bench-scaled structure are conducted, which verified that the proposed multi-taper method based method indeed significantly improves the substructure identification accuracy.

Optimal design of a high homogeneous and small-size shim coil for atomic spin gyroscope based on 0-1 linear programming

2020 ◽  
Vol 64 (1-4) ◽  
pp. 165-172
Author(s):  
Dongge Deng ◽  
Mingzhi Zhu ◽  
Qiang Shu ◽  
Baoxu Wang ◽  
Fei Yang
Keyword(s):  
Linear Programming ◽  
Power Consumption ◽  
Low Power ◽  
Optimization Design ◽  
Structural Parameters ◽  
Axial Position ◽  
Low Power Consumption ◽  
Optimal Method ◽  
Atomic Spin ◽  
Shim Coil

It is necessary to develop a high homogeneous, low power consumption, high frequency and small-size shim coil for high precision and low-cost atomic spin gyroscope (ASG). To provide the shim coil, a multi-objective optimization design method is proposed. All structural parameters including the wire diameter are optimized. In addition to the homogeneity, the size of optimized coil, especially the axial position and winding number, is restricted to develop the small-size shim coil with low power consumption. The 0-1 linear programming is adopted in the optimal model to conveniently describe winding distributions. The branch and bound algorithm is used to solve this model. Theoretical optimization results show that the homogeneity of the optimized shim coil is several orders of magnitudes better than the same-size solenoid. A simulation experiment is also conducted. Experimental results show that optimization results are verified, and power consumption of the optimized coil is about half of the solenoid when providing the same uniform magnetic field. This indicates that the proposed optimal method is feasible to develop shim coil for ASG.

A Possible Basis for Nondestructive Characterization of Ropes of Nylon 6

1997 ◽  
Vol 503 ◽  
Author(s):  
H. Jiang ◽  
M. K. Davis ◽  
R. K. Eby ◽  
P. Arsenovic
Keyword(s):  
Tensile Strength ◽  
Service Life ◽  
Fiber Diameter ◽  
Structural Parameters ◽  
Crystal Form ◽  
Nylon 6 ◽  
Remaining Service Life ◽  
Nondestructive Characterization ◽  
Fractional Content

ABSTRACTPhysical properties and structural parameters have been measured for ropes of nylon 6 as a function of the number of use operations. The fractional content of the α crystal form, sound velocity, birefringence, tensile strength and length all increase systematically and significantly with increasing the number of use operations. The fractional content of the γ crystal form and fiber diameter decrease with use. These trends indicate that the measurement of such properties and structural parameters, especially the length, provide a possible basis for establishing a reliable, rapid, and convenient nondestructive characterization method to predict the remaining service life of nylon 6 ropes.

Structural Parameters of Bacterial Plankton in Ponds with High Contents of Mineral Nitrogen

2007 ◽  
Vol 43 (5) ◽  
pp. 91-100
Author(s):  
Ye. V. Starosila ◽  
G. N. Oleynik ◽  
Yu. G. Krot
Keyword(s):  
Structural Parameters ◽  
Mineral Nitrogen
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