Multi-scale model updating of a transmission tower structure using Kriging meta-method

2016 ◽  
Vol 24 (8) ◽  
pp. e1952 ◽  
Author(s):  
F.Y. Wang ◽  
Y.L. Xu ◽  
S. Zhan
Keyword(s):  
Model Updating ◽  
Scale Model ◽  
Transmission Tower ◽  
Multi Scale ◽  
Tower Structure

Multi-scale model updating for the mechanical properties of cross-laminated timber

2016 ◽  
Vol 177 ◽  
pp. 83-90 ◽  
Author(s):  
E.I. Saavedra Flores ◽  
R.M. Ajaj ◽  
I. Dayyani ◽  
Y. Chandra ◽  
R. Das
Keyword(s):  
Mechanical Properties ◽  
Model Updating ◽  
Scale Model ◽  
Cross Laminated Timber ◽  
Multi Scale

Multi-Scale Analysis of the UHVDC Transmission Tower

2014 ◽  
Vol 680 ◽  
pp. 383-386
Author(s):  
Chun Cheng Liu ◽  
Wen Qiang Li ◽  
Shang Yu Hou ◽  
Zhao Wen He ◽  
Fan Gao
Keyword(s):  
Large Scale ◽  
Element Model ◽  
Beam Element ◽  
Scale Model ◽  
Scale Analysis ◽  
Transmission Tower ◽  
Gusset Plate ◽  
Multi Scale ◽  
Buckling Behavior ◽  
Scale Models

In order to analyze the mechanical properties of UHVDC transmission tower joint accurately, a multi-scale finite element model of the transmission tower is established with the interface between solid element model and beam element model. The model is applied to the nonlinear analysis of a key joint in a test condition .The results show that the tower destruction is caused by buckling behavior of the cross bracing member and the multi-scale model can simulate the force state of gusset-plate and the connected members realistically, which is superior to traditional large scale models. The analysis coincides with the experiment well and provides references for the transmission tower design.

scholarly journals Multi-scale model updating of a timber footbridge using experimental vibration data

2017 ◽  
Vol 34 (3) ◽  
pp. 754-780 ◽  
Author(s):  
Rafael Castro-Triguero ◽  
Enrique Garcia-Macias ◽  
Erick Saavedra Flores ◽  
M.I. Friswell ◽  
Rafael Gallego
Keyword(s):  
Structural Model ◽  
Model Updating ◽  
Ambient Vibration ◽  
Scale Model ◽  
Structural Behavior ◽  
Modal Parameters ◽  
Content Type ◽  
Multi Scale ◽  
Ambient Vibration Tests ◽  
Vibration Tests

Purpose The purpose of this paper is to capture the actual structural behavior of the longest timber footbridge in Spain by means of a multi-scale model updating approach in conjunction with ambient vibration tests. Design/methodology/approach In a first stage, a numerical pre-test analysis of the full bridge is performed, using standard beam-type finite elements with isotropic material properties. This approach offers a first structural model in which optimal sensor placement (OSP) methodologies are applied to improve the system identification process. In particular, the effective independence (EFI) method is used to determine the optimal locations of a set of sensors. Ambient vibration tests are conducted to determine experimentally the modal characteristics of the structure. The identified modal parameters are compared with those values obtained from this preliminary model. To improve the accuracy of the numerical predictions, the material response is modeled by means of a homogenization-based multi-scale computational approach. In a second stage, the structure is modeled by means of three-dimensional solid elements with the above material definition, capturing realistically the full orthotropic mechanical properties of wood. A genetic algorithm (GA) technique is adopted to calibrate the micromechanical parameters which are either not well-known or susceptible to considerable variations when measured experimentally. Findings An overall good agreement is found between the results of the updated numerical simulations and the corresponding experimental measurements. The longitudinal and transverse Young's moduli, sliding and rolling shear moduli, density and natural frequencies are computed by the present approach. The obtained results reveal the potential predictive capabilities of the present GA/multi-scale/experimental approach to capture accurately the actual behavior of complex materials and structures. Originality/value The uniqueness and importance of this structure leads to an intensive study of its structural behavior. Ambient vibration tests are carried out under environmental excitation. Extraction of modal parameters is obtained from output-only experimental data. The EFI methodology is applied for the OSP on a large-scale structure. Information coming from several length scales, from sub-micrometer dimensions to macroscopic scales, is included in the material definition. The strong differences found between the stiffness along the longitudinal and transverse directions of wood lumbers are incorporated in the structural model. A multi-scale model updating approach is carried out by means of a GA technique to calibrate the micromechanical parameters which are either not well-known or susceptible to considerable variations when measured experimentally.

Fine Damage Identification Method of Transmission Tower Based on Concurrent Multi-Scale Modeling

2014 ◽  
Vol 680 ◽  
pp. 374-378
Author(s):  
Chun Cheng Liu ◽  
Shang Yu Hou ◽  
Wen Qiang Li ◽  
Zhao Wen He
Keyword(s):  
Large Scale ◽  
Damage Identification ◽  
Wavelet Packet ◽  
Fatigue Cracks ◽  
Damage Index ◽  
Scale Model ◽  
Transmission Tower ◽  
Damage Level ◽  
Multi Scale ◽  
Identification Method

In order to study the damage problem caused by the transmission tower fatigue cracks and bolt pretightening force loss ,this paper proposes a transmission tower damage identification method based on concurrent multi-scale model, namely establish solid model on nodes of fatigue crack and bolt looseness based on large scale model., subdividing elements size. Take a practical engineering 500kV transmission towers as an example to establish a concurrent multi-scale models. This paper simulates 8 kinds of conditions including bolt pretightening force loss and angle steel crack, research shows that the sum of wavelet packet energy curvature difference can effectively identify minute damage, and then get the function relation between damage level and damage index with no noise interference, also this provides a theoretical basis for it as actual damage monitoring indicators index.

The Life Prediction of Transmission Tower Based on Multi-Scale Analysis

2014 ◽  
Vol 680 ◽  
pp. 395-398
Author(s):  
Chun Cheng Liu ◽  
Zhao Wen He ◽  
Yu Jiang Pan ◽  
Wen Qiang Li ◽  
Shang Yu Hou
Keyword(s):  
Fatigue Life ◽  
Transmission Lines ◽  
Time Course ◽  
Element Model ◽  
Scale Model ◽  
Transmission Tower ◽  
Multi Scale ◽  
Remaining Service Life ◽  
Transmission Towers ◽  
Residual Fatigue

In order to study the residual fatigue life of 500 kv transmission tower under load conditions, a multi-scale finite element model of transmission tower is established. By simulating time course of wind load, using Miner fatigue cumulative damage theory and linear S-N curve, the calculation method of transmission towers fatigue life is established. The research shows that the multi-scale model can better simulate the stress and strain state of the transmission tower, and can predict the remaining service life of the transmission tower .The research has important significance and application value for the safe operation of the transmission lines.

Three-dimensional Reconstruction of Microscopic Image Based on Multi-ST Algorithm

2020 ◽  
Vol 64 (2) ◽  
pp. 20506-1-20506-7
Author(s):  
Min Zhu ◽  
Rongfu Zhang ◽  
Pei Ma ◽  
Xuedian Zhang ◽  
Qi Guo
Keyword(s):  
3D Reconstruction ◽  
Three Dimensional ◽  
Scale Model ◽  
Microscopic Image ◽  
Multi Scale ◽  
Gaussian Pyramid ◽  
Cost Aggregation ◽  
Dimensional Reconstruction ◽  
Image Pairs ◽  
Accurate Matching

Abstract Three-dimensional (3D) reconstruction is extensively used in microscopic applications. Reducing excessive error points and achieving accurate matching of weak texture regions have been the classical challenges for 3D microscopic vision. A Multi-ST algorithm was proposed to improve matching accuracy. The process is performed in two main stages: scaled microscopic images and regularized cost aggregation. First, microscopic image pairs with different scales were extracted according to the Gaussian pyramid criterion. Second, a novel cost aggregation approach based on the regularized multi-scale model was implemented into all scales to obtain the final cost. To evaluate the performances of the proposed Multi-ST algorithm and compare different algorithms, seven groups of images from the Middlebury dataset and four groups of experimental images obtained by a binocular microscopic system were analyzed. Disparity maps and reconstruction maps generated by the proposed approach contained more information and fewer outliers or artifacts. Furthermore, 3D reconstruction of the plug gauges using the Multi-ST algorithm showed that the error was less than 0.025 mm.

Optimisation of Steel Transmission Tower Structure Using Firefly Algorithm

2017 ◽  
Vol 6 (2) ◽  
pp. 9
Author(s):  
REDDY A. ANVESH ◽  
KUMAR CH. NAVEEN ◽  
REDDY K. AVINASH ◽  
CHANDRASEKHAR K.N.V. ◽  
◽  
...  
Keyword(s):  
Firefly Algorithm ◽  
Transmission Tower ◽  
Tower Structure

Effects of parametric uncertainty on multi-scale model predictions of shock response of a pressed energetic material

2019 ◽  
Vol 125 (23) ◽  
pp. 235104 ◽  
Author(s):  
Sangyup Lee ◽  
Oishik Sen ◽  
Nirmal Kumar Rai ◽  
Nicholas J. Gaul ◽  
K. K. Choi ◽  
...  
Keyword(s):  
Energetic Material ◽  
Parametric Uncertainty ◽  
Scale Model ◽  
Multi Scale ◽  
Model Predictions ◽  
Shock Response
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