Full-Scale Tests and Numerical Simulations of Failure Mechanism of Power Transmission Towers

2018 ◽  
Vol 18 (09) ◽  
pp. 1850109 ◽  
Author(s):  
Li Tian ◽  
Liulu Guo ◽  
Ruisheng Ma ◽  
Xia Gai ◽  
Wenming Wang

Full-scale tests are conducted to investigate the load-bearing capacity and failure mechanism of power transmission towers subjected to various loading patterns (broken lines, wind and ice). Detailed finite element models of power transmission towers are established based on these experimental prototypes. To capture the member instability, the integral stability coefficients are obtained from different specifications and introduced into a user-defined material model. Subsequently, the failure analysis of power transmission towers is carried out using an explicit algorithm, and good agreement is found in comparison with experimental results. The results show that the proposed procedure is effective in simulating the power transmission tower failure process. The full-scale test and numerical simulation studies can provide a valuable database for the design of power transmission towers subjected to various loads.

2013 ◽  
Vol 732-733 ◽  
pp. 1045-1051 ◽  
Author(s):  
Qing Hua Li ◽  
Jing Bo Yang ◽  
Jun Ke Han

State Grid Corporation of China has carried out research on key technology of UHV&EHV AC and DC multi-circuit transmission lines, the research on material and structure of transmission tower is the important part. The SSZT2 tower, on which 1000 kV AC double-circuit and 500 kV AC double-circuit are arranged, is the largest power transmission capacity all over the world. Q420 high-strength tubular steel, the plug-in boards and forging flanges are used in SSZT2 tower,and the forging flange with strength classification is applied for the first time. Through the monographic study on the tower structures, wind vibration coefficient, and biaxial bending of steel tube etc. The success of full-scale test verified the reliability in design and manufacture of multi-circuit steel tubular tower for UHV and EHV. Research results of this paper can be applied in UHV transmission line projects.


Author(s):  
Kuan Ye ◽  
Kai Zhou ◽  
Ren Zhigang ◽  
Ruizhe Zhang ◽  
Chunsheng Li ◽  
...  

The power transmission tower’s ground electrode defect will affect its normal current dispersion function and threaten the power system’s safe and stable operation and even personal safety. Aiming at the problem that the buried grounding grid is difficult to be detected, this paper proposes a method for identifying the ground electrode defects of transmission towers based on single-side multi-point excited ultrasonic guided waves. The geometric model, ultrasonic excitation model, and physical model are established, and the feasibility of ultrasonic guided wave detection is verified through the simulation and experiment. In actual inspection, it is equally important to determine the specific location of the defect. Therefore, a multi-point excitation method is proposed to determine the defect’s actual position by combining the ultrasonic guided wave signals at different excitation positions. Besides, the precise quantification of flat steel grounding electrode defects is achieved through the feature extraction-neural network method. Field test results show that, compared with the commercial double-sided excitation transducer, the single-sided excitation transducer proposed in this paper has a lower defect quantization error in defect quantification. The average quantization error is reduced by approximately 76%.


2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Chung-Won Lee ◽  
Jiseong Kim ◽  
Gi-Chun Kang

Vibration and noise problems caused by a number of construction processes, specifically blasting for infrastructure development, are becoming important because of their civil appeal. In this study, a square root equation (SRE) with a 95% confidence level was proposed for predicting blasting-induced vibration through full-scale test blasting, and the vibration value predicted from this equation was located between the values predicted from the USBM (US Department of Interior, Bureau of Mines), NOF (Nippon Oil & Fats Co., Ltd.), and MCT (Ministry of Construction and Transportation) equations. Additionally, by comparing the measured noise level at full-scale test blasting with the calculated noise levels from several noise prediction equations, it was determined that the noise level predicted by the ONECRC equation had the best agreement with the measured results. However, in cases where blasting includes tunnel excavation, simultaneous measurement of vibration and noise is required to prevent damage to the surrounding facilities.


Author(s):  
Mitsuhiro Miyamoto ◽  
Haruka Okuhiro

In the present study, few studies have focused on the horizontal plane of traditional wooden houses in Japan. This study aims to examine the retrofit effects for the horizontal plane of traditional wooden houses based on full-scale tests. The first part of this paper is devoted to the experimental study performed to determine the structural behavior and characteristics of full-scale roof specimens. A horizontal shear test was conducted to obtain the fracture mode and relationship between the applied load and deformation angle. The second part deals with a static pushover analysis of the full-scale roof specimens. The results between the experimental test and the static pushover analysis are presented and discussed. The analysis model used for the static pushover analysis is proposed; the results were in good agreement with the tests.


Author(s):  
Claudio Somaschini ◽  
Tommaso Argentini ◽  
Daniele Rocchi ◽  
Paolo Schito ◽  
Gisella Tomasini

The resistance to motion of trains is an essential requisite especially while designing high-speed trains and high-capacity railway lines. The optimisation of friction effects and aerodynamic performance can be done during the design stage of a new train but the actual value of the running resistance can be inferred only by means of full-scale tests during the operation of a train. A CEN standard (EN 14067-4) describes the methodologies for the assessment of the running resistance of railway vehicles starting from full-scale test measurements. According to this standard, the speed-dependent terms of the resistance force have to be determined by means of coasting tests on railway lines, whose characteristics must be well known. Since this is not always possible and small errors on the gradient could lead to major uncertainties in the evaluation of the resistance force, a new method for the estimation of the running resistance coefficients, irrespective of the characteristics of the track is proposed in this paper. The reliability of the method is verified by comparing the results with those obtained from the procedure proposed in the CEN standard. The comparison shows that the new methodology is able to evaluate the resistance coefficients with an accuracy equivalent to that of the other methods but with fewer tests and with a more robust procedure relying on a lesser number of parameters.


Author(s):  
Z. Wu ◽  
H. Wang ◽  
W. Yu ◽  
J. Xi ◽  
W. Lei ◽  
...  

Abstract. Constructing the transmission tower from LiDAR point clouds is a fundamental step for smart grid. However, currently the transmission tower construction method relies heavily on manual editing, which is far from the practical industrial application. This paper proposes a model-driven based method to realize 3D construction of transmission tower fast and accurately. This method first generates different types of 3D tower models. Then, it calculates the direction characteristic of point clouds distribution using the obtained transmission towers point clouds. While finding the principal direction of transmission towers, the local coordinates of the transmission towers are settled. And then the key points are captured in a semi-automatically way. According to these key points, the transmission tower model that best matches the point clouds is selected using the model matching algorithm. Comparing with the existing traditional manual editing methods, the method proposed in this paper can ensure the integrity and accuracy of the reconstructed tower model using the model-driven based strategy. The proposed method makes a trade-off between manual editing and efficiency, which guarantees the quality of tower modelling. And the feasibility and practicability of the proposed method are verified by the experiments on real-world point clouds data.


2013 ◽  
Vol 838-841 ◽  
pp. 370-374
Author(s):  
Liang Wang ◽  
Wei Lian Qu ◽  
Yan Fei Li ◽  
Yi Fei Wang

Large span transmission tower is the lifeline of electricity transmission,Its collapse destroyed will causes adverse to the social and economic effects,The mechanism of the power transmission tower collapsed caused people's attention.The analysis is based on LS-DYNA program,explicit beam161 beam element is adopted to establish the finite element model for transmission towers,Analyses the collapse process of transmission tower and its failure mode with downburst load.


2018 ◽  
Vol 22 (4) ◽  
pp. 1007-1017 ◽  
Author(s):  
Li Tian ◽  
Guodong Gao ◽  
Canxing Qiu ◽  
Kunjie Rong

Statistics from past strong earthquakes revealed that electricity transmission towers were vulnerable to earthquake excitations. It is necessary to mitigate the seismic responses of power transmission towers to ensure the safety of such structures. In this research, a novel shape memory alloy-tuned mass damper is proposed, and seismic vibration control of power transmission tower using shape memory alloy-tuned mass damper based on three types of shape memory alloy materials (i.e. NiTi, M-CuAlBe, P-CuAlBe) is analyzed. The detailed three-dimensional finite element model of a power transmission tower incorporated with shape memory alloy-tuned mass damper is developed using numerical simulation software ANSYS. The control effects of shape memory alloy-tuned mass damper on the seismic vibration of power transmission tower are assessed using nonlinear time history analysis method. The interested seismic performance indices include displacement, acceleration, and base shear force. In addition to the shape memory alloy materials, the influence of seismic intensity and frequency ratio are conducted for the optimal design. It is shown that installing shape memory alloy-tuned mass damper well reduced the seismic responses of power transmission tower. The comparison between different shape memory alloys indicated that the damping of the shape memory alloy-tuned mass damper is beneficial to mitigate the vibrations.


1974 ◽  
Vol 96 (4) ◽  
pp. 323-329 ◽  
Author(s):  
W. A. Poynton ◽  
R. W. E. Shannon ◽  
G. D. Fearnehough

Shear fracture propagation is studied using an analysis based upon the thermodynamic equilibrium of a constant velocity fracture. This equation is shown to describe the behavior of all full scale tests which exhibit constant velocity propagation. This equation is developed to identify the conditions for fracture arrest; the resulting formulation is again consistent with full scale test behavior. The paper also discusses the application of the theory to existing and new pipelines.


Sign in / Sign up

Export Citation Format

Share Document