scholarly journals Applying the Principle of Variables to Solve the Problems of Forced Vibration of the plate with three clamped and the other free with concentrated load

2016 ◽  
Vol 44 ◽  
pp. 02052
Author(s):  
Ying Jie Chen ◽  
Jing Yao Wu
Keyword(s):  
Forced Vibration ◽  
The Other ◽  
Concentrated Load

Effect of Strand Indentation Types on the Development Length and Flexural Capacity of Concrete Railroad Ties Made With Different Prestressing Strands

2019 ◽  
Author(s):  
Amir Farid Momeni ◽  
Robert J. Peterman ◽  
B. Terry Beck ◽  
Chih-Hang John Wu
Keyword(s):  
The Other ◽  
Development Length ◽  
Concrete Compressive Strength ◽  
Concentrated Load ◽  
Bonding Performance ◽  
Pretensioned Concrete ◽  
Load Tests ◽  
Prestressing Strands ◽  
Wire Strand ◽  
Prestressing Strand

Pretensioned concrete prisms made with five different prestressing strand types (four 7-wire strands and one 3-wire strand) were load tested to failure to understand the effect of strand indentation types on the development length and bonding performance of these different reinforcements. The prestressing strands were denoted SA, SB, SD, SE and SF. SA was a smooth strand while the other four were indented strands. All strands utilized in manufacturing ofprisms had diameter of 3/8″ (9.52 mm). Among all types of strands, SF was the only 3-wire strand and the remaining strands were all 7-wire strands. For all types of strands, four straight strands were embedded into each concrete prism, which had a 5.5″ (139.7 mm) × 5.5″ (139.7 mm) square cross section. The strands were tensioned to 75 percent of ultimate tensile strength of strands and gradually de-tensioned when the concrete compressive strength reached 4500 psi (31.03 Mpa). A consistent concrete mixture with type III cement, water-cement ratio of 0.32 and a 6-in. slump was used for all prisms. Prisms were load tested in 3-point-bending at different embedment lengths to obtain estimations of the development length of each type of strand. Two out of three identical 69-in.-long (175.26 cm) prisms were load tested at one end and one was tested at both ends for each reinforcement type evaluated. First prisms were tested at 28-in. (71.12 cm) from the end, while second prisms were tested at 20-in. (33.02 cm) from the end. Third prisms were loaded at 16.5-in. (41.9 cm) from one end and 13-in. (33.02 cm) from the other end. Thus, a total of 20 load tests (5 strand types × 4 tests each) were conducted in this study. During each test, a concentrated load with the rate of 900 lb/min (4003 N/min) was applied at mid-span until failure occurred. Values of load, mid-span deflection, and strand endslip were continuously monitored and recorded during each test. Plots of load-vs-deflection were then compared for prisms with each strand type and span, and the maximum sustained moment was also calculated for each test. The load tests revealed that there is a large difference in the development length of the strands based on their indentation type.

Experimental Reasearch on Grinding Surface Waviness of Engineering Ceramics

2013 ◽  
Vol 770 ◽  
pp. 175-178 ◽  
Author(s):  
Yan Fei Diao ◽  
Yu Guo Wang ◽  
Bin Lin ◽  
Li Jie Li
Keyword(s):  
Experimental Research ◽  
Forced Vibration ◽  
The Self ◽  
Generation Mechanism ◽  
The Other ◽  
Alumina Ceramics ◽  
Surface Waviness ◽  
Zirconia Ceramics ◽  
Engineering Ceramics ◽  
Excited Vibration

In this paper, an experiment has been made to take vibration and surface waviness of two kinds of engineering ceramics ( zirconia ceramics and alumina ceramics) as research targets. The experimental research results show that two kinds of surface waviness are on the workpiece, one is sparse and the other one is dense. It is known that the sparse one is caused by the forced vibration. In order to find out the generation mechanism of the dense one, a further exploration has been made. It shows that the dense surface waviness is caused by the self-excited vibration. Finally, some methods are put forward to reduce the surface waviness.

Isotropic Clamped-Free Thin Annular Circular Plate Subjected to a Concentrated Load

2005 ◽  
Vol 73 (4) ◽  
pp. 658-663 ◽  
Author(s):  
Ajayi O. Adewale
Keyword(s):  
Circular Plate ◽  
Annular Plate ◽  
The Other ◽  
Load Application ◽  
Concentrated Load ◽  
Deflection Coefficient ◽  
Series Approximation ◽  
Radial Moments ◽  
Radial Moment

The problem of an isotropic annular plate clamped along one edge and free at the other and subjected to a concentrated load is solved by a series approximation. The continuity conditions of deflection, slope, shear and radial moments at the radius of load application are satisfied. Variations of deflection coefficient, radial moment coefficients and shear coefficients with radius and angle are presented.

A New Metric for Automated Stability Identification in Time Domain Milling Simulation

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Andrew Honeycutt ◽  
Tony L. Schmitz
Keyword(s):  
Time Domain ◽  
Forced Vibration ◽  
Stability Limit ◽  
Experimental Results ◽  
The Other ◽  
Sampled Data ◽  
A Value ◽  
Milling Simulation ◽  
The Stability ◽  
Over Time

A new metric is presented to automatically establish the stability limit for time domain milling simulation signals. It is based on periodically sampled data. Because stable cuts exhibit forced vibration, the sampled points repeat over time. Periodically sampled points for unstable cuts, on the other hand, do not repeat with each tooth passage. The metric leverages this difference to define a numerical value of nominally zero for a stable cut and a value greater than zero for an unstable cut. The metric is described and is applied to numerical and experimental results.

Vibration Localization in Plates With Misplaced Intermediate Supports in Two Orthogonal Directions

2003 ◽  
Author(s):  
Wei-Chau Xie ◽  
Zhihua Chen
Keyword(s):  
Forced Vibration ◽  
Natural Frequencies ◽  
Current Approach ◽  
Vibration Response ◽  
Vibration Modes ◽  
The Finite Element Method ◽  
Concentrated Load ◽  
Vibration Localization ◽  
Vibration Responses ◽  
Simple Supports

This paper investigates the effect of small misplacements on both the free vibration modes and forced vibration responses of a four-panel simply supported plate with two intermediate simple supports in two orthogonal directions. Kantorovich’s method is employed to obtain the natural frequencies and the corresponding vibration modes. Galerkin’s method is applied to determine the forced vibration response of the four-panel plate subjected to a harmonic concentrated load at the center of one of its four panels. Comparisons between numerical results obtained using the current approach and those using the exact solution and the finite element method are made to demonstrate the accuracy of the current approach. It is found that the small misplacements of the intermediate supports have dramatic effects on the vibration response of the plate. The larger the misplacement of the intermediate supports, the larger the degree of vibration localization. By judiciously introducing misplacements in the intermediate simple supports, the vibration of some of the four panels may be controlled.

scholarly journals Experimental Investigation for The Flow Induced Vibration for Pipe Inside Water

2020 ◽  
Vol 23 (1) ◽  
pp. 61-67
Author(s):  
Ansam Adel Mohammed ◽  
Haitham Mohsin Salman
Keyword(s):  
Forced Vibration ◽  
The Other ◽  
Pipe Conveying Fluid ◽  
Maximum Deflection ◽  
Flow Induced Vibration ◽  
Effect Difference ◽  
Excitation Frequencies ◽  
Different Diameters ◽  
Conveying Fluid ◽  
Forced Excitation

Forced vibration has been experimentally investigated on a model consists of circular pipe with1.6m length. The pipe built in tank (1.2m length, 0.6m height and 0.6m width) horizontally at 0.4m height with two different diameters d=15mm and d=35mm. The pipe conveying laminar flow in the fully developed region, of Reynolds number equals 2000. The experimental results of span pipe conveying water at five stations of forced excitation vibration were studied. The harmonic forced vibration with two different excitation frequencies (10 Hz and 15 Hz) are imposed at all of the five locations. The distance between two stations is (0.2m). Two conditions of pipe environment have been applied, the first in air and the other was immersed in water. It is concluded that the effect of flow induced vibration due to the pipe conveying fluid increases the maximum deflection when the fluid speed increases. The water surrounds the pipes reduce the effect of excitation vibration about (33 – 46%). The effect difference between the excitation frequencies was about (4 – 7%).

Stromatoporoids from the Famennian (Devonian) Wabamun Formation, Normandville oilfield, north–central Alberta, Canada

1988 ◽  
Vol 62 (03) ◽  
pp. 411-419 ◽  
Author(s):  
Colin W. Stearn
Keyword(s):  
Patch Reef ◽  
Abundant Species ◽  
The Other ◽  
North Central ◽  
Biotic Crisis

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species isStylostroma sinense(Dong) butLabechia palliseriStearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described areClathrostromacf.C. jukkenseYavorsky,Gerronostromasp. (a columnar species), andStromatoporasp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).

D. The Line Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 207-244
Author(s):  
R. P. Kraft
Keyword(s):  
Variable Stars ◽  
The Other ◽  
Line Spectrum ◽  
Afternoon Session ◽  
Empirical Information ◽  
Pulsating Variable Stars ◽  
Almost Continuous ◽  
Informal Approach

(Ed. note:Encouraged by the success of the more informal approach in Christy's presentation, we tried an even more extreme experiment in this session, I-D. In essence, Kraft held the floor continuously all morning, and for the hour and a half afternoon session, serving as a combined Summary-Introductory speaker and a marathon-moderator of a running discussion on the line spectrum of cepheids. There was almost continuous interruption of his presentation; and most points raised from the floor were followed through in detail, no matter how digressive to the main presentation. This approach turned out to be much too extreme. It is wearing on the speaker, and the other members of the symposium feel more like an audience and less like participants in a dissective discussion. Because Kraft presented a compendious collection of empirical information, and, based on it, an exceedingly novel series of suggestions on the cepheid problem, these defects were probably aggravated by the first and alleviated by the second. I am much indebted to Kraft for working with me on a preliminary editing, to try to delete the side-excursions and to retain coherence about the main points. As usual, however, all responsibility for defects in final editing is wholly my own.)

C. The Continuous Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney
Keyword(s):  
Continuous Spectrum ◽  
Variable Stars ◽  
Velocity Fields ◽  
The Other ◽  
Line Spectrum ◽  
Direct Information ◽  
Thermodynamic Structure ◽  
Diagnostic Interpretation ◽  
Pulsating Variable Stars ◽  
The Continuum

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.

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