Vibration Tests With a 1/13-Scaled 3-D Model of the Folsom Dam Tainter-Gate and Its Prediction by Theory

2006 ◽  
Author(s):  
Keiko Anami ◽  
Noriaki Ishii ◽  
Charles W. Knisely ◽  
Robert V. Todd ◽  
Tatsuya Oku
Keyword(s):  
Dynamic Instability ◽  
Vibration Test ◽  
Test Results ◽  
Bending Vibration ◽  
Coupled Mode ◽  
Basic Assumptions ◽  
Vibration Tests ◽  
D Model ◽  
Theoretical Analyses ◽  
Made In

This study presents 3-D model gate vibration test results demonstrating violent spontaneous vibrations and validating the basic assumptions made in previously published theoretical analyses. First, the design of a 1/13-scaled 3-D model of Folsom dam Tainter-gate is presented, in which the streamwise natural bending vibration mode of the skinplate, measured in the field vibration tests on the remaining Folsom gate, is shown to be correctly replicated with the aid of FEM simulations. Secondly, in-air and in-water vibration test results with the 1/13-scaled 3-D model are presented, reproducing the intense coupled-mode self-excited vibrations. Thirdly, test results are plotted on a theoretically calculated stability criterion diagram to confirm the validity of the theoretical analysis. Finally, the intense dynamic instability of the Folsom gate, which could have caused its failure, is presented.

Coupled-Mode Dynamic Instability of Tainter Gates With Parallel Bending Vibration of the Skinplate

2010 ◽  
Author(s):  
Keiko Anami ◽  
Noriaki Ishii ◽  
Takuma Tsuji ◽  
Tatsuya Oku ◽  
Masaru Goto ◽  
...  
Keyword(s):  
Dynamic Instability ◽  
Laboratory Model ◽  
Dynamic Coupling ◽  
Bending Vibration ◽  
Coupled Mode ◽  
Excited Vibration ◽  
Rotational Vibration ◽  
The Usa ◽  
Vibration Mechanism ◽  
Vibration Tests

As part of the investigation of the dynamic instability of the gate closely related to the Folsom Dam Tainter-gate failure, and in order to assure the dynamic stability of the gate, the field vibration tests on three full-scale operational Tainter-gates were conducted. From these tests, the possible existence of another coupled-mode self excited vibration mechanism, which involves the dangerous dynamic coupling of the whole gate rigid-body rotational vibration with a “parallel” bending vibration of the skinplate was suggested. This paper presents the mechanism of the suggested coupled-mode self-excited vibration, theoretical analysis for the suggested dynamic instability, and 2-dimensional laboratory model tests results. Further, the need for retrofit countermeasures for Tainter gates which are currently installed in both Japan and the USA and susceptible to this dangerous coupled-mode dynamic instability is emphasized.

Field Measurement of Dynamic Instability of a 50-Ton Tainter-Gate

2007 ◽  
Author(s):  
Keiko Anami ◽  
Noriaki Ishii ◽  
Charles W. Knisely ◽  
Tatsuya Oku
Keyword(s):  
Theoretical Model ◽  
Degrees Of Freedom ◽  
Dynamic Instability ◽  
Test Results ◽  
Model Studies ◽  
Coupled Mode ◽  
Excited Vibration ◽  
Concurrent Development ◽  
2D And 3D ◽  
Maintenance Plan

The 2-degrees-of-freedom coupled-mode self-excited vibration of Tainter gate has been demonstrated in hydraulic model studies of 2D and 3D gate models. The concurrent development of a theoretical model has permitted the prediction that some full-scale Tainter-gates could be potentially susceptible to this coupled-mode self-excited vibration. However, there are many people who regard with suspicion the prediction that a massive Tainter-gate might actually undergo this type of vibrations. In response to these skeptics, this paper presents the test results from an actual operational 50-ton Tainter-gate to determine its propensity for large-amplitude self-excited vibration. Further, the previously developed theoretical analysis was applied to the tested gate to uncover an essential dynamic instability for this installation, as well as to provide a framework for the design of a retrofit and an optimized maintenance plan.

ЦИФРОВОЙ ИЗОЛЯТОР В СПЕЦИАЛИЗИРОВАННОМ КОРПУСЕ, ВЫПОЛНЕННОМ ПО ТЕХНОЛОГИИ LTCC

2020 ◽  
Vol 96 (3s) ◽  
pp. 392-395
Author(s):  
В.А. Бутузов ◽  
А.Е. Назаренко ◽  
Н.Ю. Дмитриев ◽  
В.А. Трофимов ◽  
В.А. Косевский ◽  
...  
Keyword(s):  
Low Temperature ◽  
Data Rate ◽  
Test Results ◽  
Made In

Представлены результаты разработки цифрового изолятора на основе интегрального микротрансформатора в специализированном корпусе, выполненном по технологии низкотемпературной совместно обжигаемой керамики (LTCC). Согласно результатам измерений тестовых образцов максимальная скорость передачи данных разработанного цифрового изолятора - не менее 30 Мбит/с. The paper presents the results of the development of a digital insulator based on an integral microtransformer in a specialized package made in technology of low-temperature co-fired ceramics. The isolator is a microassembly consisting of a transceiver chip and an integrated transformer. According to the test results, the maximum data rate speed of the developed digital insulator is not less than 30 Mbit/s.

Testing and Analysis of the Dynamic Parameters of 3D Reciprocating Compressor Foundation

2012 ◽  
Vol 204-208 ◽  
pp. 4400-4405
Author(s):  
Xin Lin Wan ◽  
Su Zhang
Keyword(s):  
Vibration Test ◽  
Reciprocating Compressor ◽  
Dynamic Parameters ◽  
Test Results ◽  
Large Size ◽  
Test Technology ◽  
Forced Vibration Test ◽  
Machine Base ◽  
Compressor Foundation ◽  
Data Processing Methods

It is necessary to test dynamics parameters of foundations at construction ground of large-size dynamic machine base. This paper elaborate the test technology and data processing methods on the basis of the block forced vibration test with engineering example, and test results are analyzed and discussed.

Experimental and analytical investigation on the in-plane dynamic instability of arches owing to parametric resonance

2017 ◽  
Vol 24 (19) ◽  
pp. 4419-4432 ◽  
Author(s):  
Airong Liu ◽  
Zhicheng Yang ◽  
Hanwen Lu ◽  
Jiyang Fu ◽  
Yong-Lin Pi
Keyword(s):  
Parametric Resonance ◽  
Dynamic Instability ◽  
Damping Ratio ◽  
Analytical Investigation ◽  
Engineering Practice ◽  
Test Results ◽  
Periodic Load ◽  
Shallow Arches ◽  
Excitation Frequencies ◽  
Critical Regions

When an arch is subjected to a periodic load, it may lose in-plane stability dynamically owing to parametric resonance. Previous investigations have been concentrated on in-plane dynamic buckling of pin-ended shallow arches. However, in engineering practice, fixed arches with different rise-to-span ratios are often encountered. Little research on in-plane dynamic instability of deep fixed arches has been reported in the literature. This paper is concerned with experimental and analytical investigations for in-plane dynamic instability of fixed circular arches with rise-to-span ratios 1/8–1/2 under a central periodic load owing to parametric resonance. Experiments are carried out to determine the in-plane frequency and damping ratio of arches, to investigate critical regions of frequencies and amplitudes of the periodic load for in-plane dynamic instability of arches, and to explore effects of the rise-to-span ratio and additional weights on dynamic instability. The analytical method for determining the region of excitation frequencies and amplitudes of the periodic load causing in-plane instability of the arch is established using the Hamilton’s principle by accounting for effects of additional concentrated weights. Comparisons of analytical solutions with test results show that they agree with each other quite well. These results show that the rise-to-span ratio significantly influences the bandwidth of regions of critical excitation frequencies for in-plane dynamic instability of arches. The critical frequencies of the periodic load and their bandwidth increase with a decrease of the rise–span ratio of the arch, whereas the corresponding amplitude of the periodic load decreases at the same time. It is also found that the central concentrated weight influences in-plane dynamic instability of arches significantly. As the weight increases, the critical frequencies of excitation and their bandwidth for in-plane dynamic instability of arches decreases, whereas the corresponding amplitude of excitation increases.

Field Tests of Guide Vanes and Runner Blades of a Large Bulb Turbine for Output Deficiency Diagnosis

2012 ◽  
Vol 212-213 ◽  
pp. 1057-1061 ◽  
Author(s):  
Zhong Liu ◽  
Zhu Qing Huang ◽  
Shu Yun Zou ◽  
Hong De Rao
Keyword(s):  
Field Tests ◽  
Economic Loss ◽  
Hydropower Plant ◽  
Test Results ◽  
Guide Vanes ◽  
Factors Affecting ◽  
Runner Blade ◽  
Main Factors ◽  
Theoretical Analyses ◽  
Bulb Turbine

The 3# bulb turbine in Hongjiang Hydropower Plant has faced the problem of output deficiency since its commission in Sept. 2003, which caused a large economic loss. Following simple theoretical analyses on the main factors affecting the turbine’s output and efficiency, the field test schemes were determined to measure the shapes and intervals of guide vanes and runner blades of the 3#, 5# and 6# turbines. The test results discover that the average blade intervals of the 3# turbine are generally less than those of the 5# one. Suggestions on runner blade installation adjustment and combined curve modification are given.

Ambient vibration test results of the Imperial County Services Building

1983 ◽  
Vol 73 (6A) ◽  
pp. 1895-1902
Author(s):  
Gerard C. Pardoen
Keyword(s):  
Strong Motion ◽  
Ambient Vibration ◽  
Vibration Test ◽  
Test Results ◽  
Structural Failure ◽  
Imperial Valley ◽  
Ambient Vibration Test ◽  
Significant Interest ◽  
First Time ◽  
County Services

Abstract The ambient vibration test results conducted on the Imperial County Services Building prior to the 15 October 1979 Imperial Valley earthquake are summarized. These results are of significant interest because the Imperial County Services Building has been the source of many postearthquake investigations due to the fact that the 1979 earthquake represented the first time a building instrumented with strong motion recorders suffered and recorded the major structural failure.

scholarly journals Pengembangan Rubrik Penskoran pada Asesmen Otentik untuk Materi Volume dan Luas Balok

2020 ◽  
Vol 4 (2) ◽  
pp. 275
Author(s):  
Yunita Rochmawati Jonan
Keyword(s):  
Authentic Assessment ◽  
Student Response ◽  
Small Scale ◽  
Development Research ◽  
Test Results ◽  
Assessment Of Learning ◽  
Teachers And Students ◽  
Scoring Rubric ◽  
Large Groups ◽  
Made In

ABSTRAK Tujuan penelitian pengembangan ini adalah menghasilkan sebuah rubrik penskoran pada asesmen otentikuntuk materi volume dan luas balok yang dapat digunakan oleh guru dan siswa. Rubrik ini dibuat sesuai dengan standar penilaian dalam kurikulum 2013. Penelitian pengembangan (R&D) ini menggunakan model Borg and Gall yang terdiri dari lima tahap yaitu penelitian dan pengumpulan data awal, perencanaan, pengembangan format produk, uji coba skala kecil, revisi akhir dan penyempurnaan produk. Hasil penelitian pengembangan ini berupa rubrik penyekoran holistik dan analitik dengan nilai sangat valid sebesar 94%. Analisis dari penelitian ini adalah angket kebutuhan bagi guru dan siswa sedangkan uji coba dilakukan melalui perorangan, kelompok kecil dan kelompok besar. Sedangkan kelayakan rubrik penskoran dari penilaian oleh ahli dengan menggunakan angket uji validitas materi, hasil belajar siswa, respon siswa serta tanggapan guru pengajar. Hasil penelitian ini menunjukkan bahwa rubrik penskoran ini efektif dalam membantu memperbaiki hasil ulangan dan cukup praktis serta dapat dipergunakan untuk memberikan penilaian hasil belajar yang sesuai dengan kurikulum 2013. Kata kunci: rubrik, penskoran, asesmen otentik.   ABSTRACT The purpose of this development research is to produce a scoring rubric on an authenticity assessment for the volume and area materials that can be used by teachers and students. The rubric is made in based on the assessment standards in the 2013 curriculum. This development research (R&D) uses the Borg and Gall model consisting of five stages of preliminary data research and collection, planning, product format development, small-scale trials, final revisions and product enhancements. The results of this development research include holistic and analytic scoring rubric with a very valid score of 94%. The rubric is analyzed fromquestionnaire for teachers and students, while trials are conducted through individuals, small groups and large groups. The feasibility of the scoring rubric from assessment by members by using the material validity test questionnaire, student learning results, student response and teacher responses. The results of this study show that the scoring rubric is effective in helping to improve the test results and is practical and can be used to provide assessment of learning outcomes in accordance with the 2013 curriculum. Keywords: rubric, scoring, authentic assessment.

scholarly journals The Effect of Technological Treatments and Loads on the Service Life of Fillet Welds

2020 ◽  
pp. 21-25
Author(s):  
Janusz Lewandowski ◽  
Dariusz Rozumek
Keyword(s):  
Service Life ◽  
Stress Ratio ◽  
Fatigue Cracks ◽  
Constant Stress ◽  
Fillet Welds ◽  
Test Results ◽  
Technological Treatment ◽  
Technological Treatments ◽  
Made In

The paper presents test results concerning the service life of fillet welds made in steel S355. In addition, the article discusses the initiation and growth of fatigue cracks in specimens subjected to bending with torsion. The tests were performed in relation to constant stress ratio R = -1 and 0. The results presented in the article take into account the effect of the technological treatment on the service life of the specimens. The tests revealed longer service life of the specimens not subjected to the technological treatment, both when R = -1 and 0.

scholarly journals The PENGARUH KEMASAN DAN DURABILITY MAKANAN RINGAN BUATAN MALAYSIA TERHADAP ETNOSENTRISME KONSUMEN DI BATAM

2019 ◽  
Vol 4 (1) ◽  
pp. 132
Author(s):  
Tiurniari Purba
Keyword(s):  
Multiple Regression ◽  
Significant Influence ◽  
Research Tool ◽  
Test Results ◽  
F Test ◽  
Statistical Software ◽  
Consumer Ethnocentrism ◽  
Regression Test ◽  
Snack Products ◽  
Made In

This study aims to determine the effect of variable packaging and durability on consumer ethnocentrism in Batam, both partially and simultaneously. The background of this research is due to the rise of types of snack products made in Malaysia circulating in every type of retail in Batam, and very well-selling. This research will be analyzed quantitatively with a research tool using a questionnaire. The results of the questionnaire will be processed with the help of SPSS statistical software. As for what will be tested is the multiple regression test. Regression test results showed that the packaging had no effect on consumer ethnocentrism in Batam. While the durability variable shows a significant influence on consumer ethnocentrism. Simultaneously the F test shows that both packaging and durability affect ethnocentrism. While the determination coefficient test results indicate that the determination test output for the R Square value of 0.817 means that the magnitude of the contribution or contribution of the X1 and X2 variables of 82% to the Y variable and the rest of 18% is the influence of other variables not mentioned in this study.   Keywords: Packeging, Durability, Etnosentrisme, Snack

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