Structural Parameter Identification Based on Equivalent Single Degree Systems

2010 ◽  
Vol 450 ◽  
pp. 510-513
Author(s):  
Yan Wei Wang ◽  
Zi Fa Wang ◽  
Rui Zhi Wen
Keyword(s):  
Numerical Simulation ◽  
Differential Evolution ◽  
Parameter Identification ◽  
Physical Parameter ◽  
Optimization Algorithm ◽  
New Method ◽  
Structural Parameter ◽  
Physical Parameters ◽  
Single Degree

In order to solve the problems of optimization algorithm used to identify the physical parameters of structures, a new method based on a series of equivalent single degree systems is proposed in this paper. The key idea of the method is that a multi-degree system can be represented by a series of single degree systems that can be identified one by one to perform the identification of the whole system. This method can not only decrease the dimensions of optimization algorithm, but also reduce the amount of estimation work in searching for the bound of parameters, and at the same time improve the identification results when parameters might suddenly change. In the numerical simulation of the physical parameter identification of a multi-degree system, Differential evolution is one of the optimization algorithm methods which are used to identify a series of equivalent single degree systems instead of the multi-degree system they represent, and the identification results prove that the method proposed in this paper is valid.

scholarly journals A New Physical Parameter Identification Method for Two-Axis On-Road Vehicles: Simulation and Experiment

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Minyi Zheng ◽  
Peng Peng ◽  
Bangji Zhang ◽  
Nong Zhang ◽  
Lifu Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Parameter Identification ◽  
Physical Parameter ◽  
Mass Matrix ◽  
Estimation Method ◽  
Least Square Method ◽  
Least Square ◽  
Percentage Error ◽  
Physical Parameters ◽  
Identification Method

A new physical parameter identification method for two-axis on-road vehicle is presented. The modal parameters of vehicle are identified by using the State Variable Method. To make it possible to determine the matricesM,C, andKof the vehicle, a known mass matrixΔMis designed to add into the vehicle in order to increase the number of equations ensuring that the number of equations is more than the one of unknowns. Therefore, the physical parameters of vehicle can be estimated by using the least square method. To validate the presented method, a numerical simulation example and an experiment example are given in this paper. The numerical simulation example shows that the largest of absolute value of percentage error is 1.493%. In the experiment example, a school bus is employed in study for the parameter identification. The simulation result from full-car model with the estimated physical parameters is compared with the test result. The agreement between the simulation and the test proves the effectiveness of the proposed estimation method.

Development of Physical-Parameter Identification Procedure for Energy-Dissipated Buildings with Symmetric Ductile Braces

2013 ◽  
Vol 479-480 ◽  
pp. 1149-1154
Author(s):  
Ming Chih Huang ◽  
Yen Po Wang ◽  
Tzu Kang Lin ◽  
Jer Fu Wang
Keyword(s):  
System Identification ◽  
Parameter Identification ◽  
Physical Parameter ◽  
Primary Structure ◽  
Substantial Reduction ◽  
Physical Parameters ◽  
Hysteretic Model ◽  
Identification Procedure ◽  
Restoring Force ◽  
Energy Dissipated

In this paper, a pseudo-single-degree-of-freedom system identification procedure is developed to investigate the dynamic characteristics of energy-dissipated buildings equipped with symmetric ductile braces (SDBs). The primary structure is assumed to be linear on account of substantial reduction of seismic forces due to the installation of SDBs for which a bilinear hysteretic model is considered. The hysteretic model is in turn characterized by a backbone curve by which the multi-valued restoring force is transformed into a single-valued function. With the introduction of backbone curves, the system identification analysis of inelastic structures is significantly simplified. The proposed algorithm extracts individually the physical parameters of each primary structure and each energy-dissipation device that are considered useful information in the structural health monitoring. A numerical example is conducted to demonstrate the feasibility of using the proposed technique for physical parameter identification of partially inelastic energy-dissipated buildings.

Physical Parameter Identification of Laminates Based on Thermal Deformation Measurements

1995 ◽  
Author(s):  
Werner Konrad ◽  
Bernd Caesar
Keyword(s):  
Parameter Identification ◽  
Physical Parameter ◽  
High Precision ◽  
Model Updating ◽  
Nodal Point ◽  
Design Parameters ◽  
Physical Parameters ◽  
Spherical Mirror ◽  
Load Case ◽  
Space Applications

Abstract High precision structures, as telescope mirrors for space applications, require high thermal stability and structural stiffness combined with low weight. Laminate structures with their special properties can satisfy these stringent requirements. Model updating and physical parameter identification on the basis of measurements can be applied to optimize such structures or define correction measures w.r.t. manufacturing inaccuracies. In classic update procedures correction factors are used to improve physical parameters. The definition of correction differences which are suitable for parameters with zero starting values or values changing from positive to negative as it may be the case for the layer orientations of a laminate is presented. High precision structures require high accurate measuring methods for the test. Thermal deformations can be measured by holographic, interferometric methods with high precision in the μm range. An interferometric contour map can be compared with the nodal point displacements of a Finite Element model by special spline functions called Zernike’s polynomials. The equations to determine the various design parameters or material properties may not be linear independent, depending on the applied thermal load case. The degree of correlation between the various parameters is investigated. The results are used to optimize the load case selection and to improve error localization methods. The proposed method is applied to a segment of a high stability spherical mirror plate with real measuring data.

Structural Physical Parameter Identification Based on Empirical Genetic-Simplex Algorithm and Structural Dynamic Response

2011 ◽  
Vol 94-96 ◽  
pp. 1998-2004
Author(s):  
Li Ping Jiang ◽  
Wei Liu ◽  
Lei Shi ◽  
Yan Liu
Keyword(s):  
Genetic Algorithm ◽  
Dynamic Response ◽  
Parameter Identification ◽  
Physical Parameter ◽  
Degrees Of Freedom ◽  
Simplex Algorithm ◽  
Physical Parameters ◽  
Running Speed ◽  
Structural Dynamic ◽  
Calculation Step

In the complex conversion analysis of multi-degrees of freedom，large calculation count needed in each calculation step of Genetic Algorithm limits the running speed of genetic algorithm. So the positive calculation count to be reduced is an effective method to enlarge the range of GA’s application. Empirical Genetic-Simplex Algorithm (EGSA) proposed in this paper is one of the effective methods to solve the problem. This method is applied to structural physical parameters identification based on the structural dynamic response. The result shows that EGSA has many advantages on precision, efficiency in searching, strong to resist the noise, and good adaptation to the incomplete information.

scholarly journals Parameter identification method of hydraulic automatic gauge control system based on chaotic wolf pack optimization algorithm

AIP Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 055302
Author(s):  
Yong Zhu ◽  
Guangpeng Li ◽  
Shengnan Tang ◽  
Wanlu Jiang ◽  
Zhijian Zheng
Keyword(s):  
Control System ◽  
Parameter Identification ◽  
Optimization Algorithm ◽  
Identification Method ◽  
Automatic Gauge Control

scholarly journals Physical Parameter Identification Algorithm Modeling for Complex Microsystem via Triangulation Functions

2018 ◽  
Vol 7 (4.36) ◽  
pp. 962
Author(s):  
Elena N. Meshcheryakova ◽  
. .
Keyword(s):  
Parameter Identification ◽  
Physical Parameter ◽  
Delaunay Triangulation ◽  
Model Development ◽  
Physical Object ◽  
Identification Algorithm ◽  
Classification Analysis ◽  
Advantages And Disadvantages ◽  
Object Parameters ◽  
D Model

This article describes the possibility of triangulation function use for the classification, analysis and identification of complex microsystem physical object parameters. They analyzed the existing methods and identification algorithms, their advantages and disadvantages are highlighted. The existing methods of triangulation are considered, the possibility of Delaunay triangulation is described for surfactant signal 3-D model development and analysis. They developed the algorithm to identify the state of an object using the triangulation function that takes into account the change of node coordinates and the length of the triangulation grid edges. They presented the visual UML model. The conclusions are drawn about the possibility of triangulation function use for the analysis of complex microsystem state.  

HEXAGON-STRIPE TRANSITION AT THE MAGNETIC FIELD INDUCED PHASE TRANSFORMATIONS OF THE MAGNETORHEOLOGICAL SUSPENSIONS

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2345-2351 ◽  
Author(s):  
A. CEBERS
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Physical Parameters ◽  
Phase Boundaries ◽  
Modulated Phases ◽  
Magnetorheological Suspensions ◽  
Perturbed State ◽  
Magnetorheological Suspension ◽  
The Magnetic Field ◽  
Hele Shaw Cell

The phase diagram of the magnetorheological suspension allowing for the modulated phases in the Hele-Shaw cell under the action of the normal field is calculated. The phase boundaries between the stripe, the hexagonal and the unmodulated phases in dependence on the layer thickness and the magnetic field strength are found. The existence of the transitions between the stripe and the hexagonal phases at the corresponding variation of the physical parameters is illustrated by the numerical simulation of the concentration dynamics in the Hele-Shaw cell. It is remarked that those transitions in the case of the magnetorheological suspensions can be caused by the compression or the expansion of the layer. Among the features noticed at the numerical simulation of the concentration dynamics in the Hele-Shaw cell are: the stripe patterns formed from the preexisting hexagonal structures are more ordered than arising from the initial randomly perturbed state; at the slightly perturbed boundary between the concentrated and diluted phases the hexagonal and the inverted hexagonal phases are formed and others.

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