The Natural Bending Vibration of the Continuous Beam and the Impact Factor of Bridge

2011 ◽  
Vol 90-93 ◽  
pp. 1245-1249 ◽  
Author(s):  
Xiang Rong Yuan
Keyword(s):  
Impact Factor ◽  
Impact Force ◽  
Bending Moment ◽  
Highway Bridges ◽  
Mode Shapes ◽  
Impact Factors ◽  
Beam Model ◽  
Continuous Beam ◽  
The Impact ◽  
Selection Of

The natural frequencies and mode shapes of 2, 3 and 4 spans continuous beam with universal cross section are calculated, and these dynamic parameters of 2 spans continuous beam model are measured. From the analysis and the model test, the locations of the maximum curvatures of the mode shapes are determined, and comparing that with the maximum bending moment of the beam under the action of uniformly distributed load, the selection of the natural frequency of the beam is discussed with the General Code for Design of Highway Bridges and Culverts as the impact factors of the beam is calculated. It is shown from the results of the analysis and the test that, for the impact factor, when the effect of positive bending moment caused by impact force is calculated, the fundamental frequency must be used as shown in the General Code, and the 2nd or 3rd frequency must be used when the effect of negative bending moment caused by impact force is calculated. The selection of the frequency should be combined with the mode shape into account for the specific circumstances.

Dynamic Test and Analysis of Curved Steel Box Girder Bridges

2005 ◽  
Vol 1928 (1) ◽  
pp. 165-173 ◽  
Author(s):  
Dongzhou Huang
Keyword(s):  
Dynamic Loading ◽  
Bending Moment ◽  
Highway Bridges ◽  
Impact Factors ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Steel Box Girder ◽  
The Impact ◽  
Curved Steel

This paper presents experimental and analytical impact factors for two existing curved steel box girder bridges. A Florida Department of Transportation test truck with a total weight of 468.8 kN applied the dynamic loading. The truck speed was incrementally increased from crawl to design speed. To evaluate the test results, the truck was simulated as a nonlinear vehicle model with 15 degrees of freedom. The bridge deck surface was assumed to be good and was simulated as a random process. Test and analytical results show that the impact factors of torsion are normally less than 30%, as are the impact factors of bending moment for bridges with span lengths less than 39 m. The impact factors of vertical shear are generally less than 15%, as are the impact factors of bending moment for bridges with span lengths greater than 50 m. The current AASHTO Guide Specifications for Horizontally Curved Highway Bridges appears to overestimate the dynamic loading of curved steel box girder bridges, especially for bridges with span lengths greater than 50 m. The research results are instructive and applicable to both bridge design and bridge load rating.

Dynamics of Human Legs Subjected to Posterior Impact

1991 ◽  
Vol 113 (1) ◽  
pp. 127-133
Author(s):  
J. F. Wilson
Keyword(s):  
Impact Force ◽  
Bending Moment ◽  
Lower Leg ◽  
Impact Loads ◽  
Beam Model ◽  
Parametric Studies ◽  
System Variables ◽  
The Impact ◽  
Horizontal Step ◽  
Dynamic Moment

This is a dynamic analysis of a three-mass, hinged beam model representing a standing human struck suddenly with a posterior, horizontal, step impact force. The results of parametric studies, presented in terms of nondimensional system variables, show the essential features of the dynamic moment responses in the lower leg. Included are the effects of the distribution of body mass, the location of the impact force, and the base fixity, with and without slip. Closed-form results show that the point of impact is not always the point of maximum bending moment on the lower leg. For step impact loads applied near the knee joint, peak moments are predicted near the midlength of the lower leg, the location coincident with about half of the observed fractures to the tibia and fibula of pedestrians struck by car bumpers near the knees.

Research on Impact Factor of Simple Composite Box Beam under Vehicle Loads

2011 ◽  
Vol 382 ◽  
pp. 471-476
Author(s):  
Yun Sheng Li ◽  
Li Li Shi ◽  
Shuai Li
Keyword(s):  
Impact Factor ◽  
Dynamic Effect ◽  
Highway Bridges ◽  
Impact Factors ◽  
Vehicle Speed ◽  
Heavy Vehicles ◽  
Wheel Load ◽  
Vehicle Loads ◽  
Heavy Loads ◽  
The Impact

Commonly the vibration due to vehicle loads has no apparently impact on highway bridges, but it is unneglectable when the heavy vehicles load on highway bridges. The impact factor is usually used to define the dynamic effect under vehicle loads in most design code. In this paper, the models of simple composite box beams with different span and the models of two simplified heavy vehicles are established respectively. The impact factors are calculated when the heavy loads pass though bridges at different speed under different load conditions. In addition, the change laws of the impact factors and the influence of different vehicle models on the impact factors are analyzed. Analysis results show that, not only the impact factor are increased with vehicle speed, but also the amplitude and period are all increased. In normal speed range, the influence of speed on the impact factors appears rising trend overall. For the bridge with same span, the impact factors under the double wheel load are smaller than that under single wheel load.

Analysis of the journal impact factor and related bibliometric indicators in education and educational research category

2021 ◽  
pp. 1-22
Author(s):  
Metin Orbay ◽  
Orhan Karamustafaoğlu ◽  
Ruben Miranda
Keyword(s):  
Impact Factor ◽  
Educational Research ◽  
Journal Impact Factor ◽  
Impact Factors ◽  
Bibliometric Indicators ◽  
Strongly Correlated ◽  
Starting Point ◽  
Consistent Assessment ◽  
The Impact ◽  
Journal Impact

This study analyzes the journal impact factor and related bibliometric indicators in Education and Educational Research (E&ER) category, highlighting the main differences among journal quartiles, using Web of Science (Social Sciences Citation Index, SSCI) as the data source. High impact journals (Q1) publish only slightly more papers than expected, which is different to other areas. The papers published in Q1 journal have greater average citations and lower uncitedness rates compared to other quartiles, although the differences among quartiles are lower than in other areas. The impact factor is only weakly negative correlated (r=-0.184) with the journal self-citation but strongly correlated with the citedness of the median journal paper (r= 0.864). Although this strong correlation exists, the impact factor is still far to be the perfect indicator for expected citations of a paper due to the high skewness of the citations distribution. This skewness was moderately correlated with the citations received by the most cited paper of the journal (r= 0.649) and the number of papers published by the journal (r= 0.484), but no important differences by journal quartiles were observed. In the period 2013–2018, the average journal impact factor in the E&ER has increased largely from 0.908 to 1.638, which is justified by the field growth but also by the increase in international collaboration and the share of papers published in open access. Despite their inherent limitations, the use of impact factors and related indicators is a starting point for introducing the use of bibliometric tools for objective and consistent assessment of researcher.

scholarly journals Editorial from the Editor in Chief: Impact factors and open access publishing

2006 ◽  
Vol 24 (4) ◽  
pp. 467-468
Author(s):  
Dieter H.H. Hoffmann
Keyword(s):  
Impact Factor ◽  
Ultrashort Pulses ◽  
Dense Matter ◽  
High Energy ◽  
Research Field ◽  
High Energy Density ◽  
Open Access Publishing ◽  
Impact Factors ◽  
Particle Beams ◽  
The Impact

The primary goal of Laser and Particle Beams as part of the Cambridge University Press is the dissemination of knowledge in our research field. How effective we are in this respect is not easy to determine. But the impact factor published annually in June by Thomson ISI® 2005 Journal Citation Reports (JCR), gives at least an indication and a method to compare other journals in the field. In this respect, Laser and Particle Beams is a journal with a very high ranking in the field of applied physics, but it also compares very well to journals in other field of physics. The impact factor of a journal gives an account of how often an average paper in the journal is referred to, in a two year time span after publication. The current impact factor of 2.59 is based on an evaluation conducted in 2005 of Laser and Particle Beams publications of 2003 and 2004. During the evaluation period (2005), Laser and Particle Beams publications were cited about 1000 times. The topics that attracted most attention were Fast Ignition (Deutsch, 2004; Mulser & Schneider, 2004a; Hora, 2004; Mulser & Bauer, 2004b), Inertial Fusion Targets (Borisenko et al., 2003), and Ion and Electron Acceleration in laser plasma and Ultrashort Pulses (Shorokhov & Pukhov, 2004; Osman et al., 2004; Malka & Fritzler, 2004; Limpouch et al., 2004; Pegoraro et al., 2004). However, the editorial boards of Laser and Particle Beams strongly encourage authors to submit their results in High Energy Density Physics, the emerging field of Warm Dense Matter, Pulsed Power and Accelerator Physics and Technology.

scholarly journals Phononic Band Gap and Free Vibration Analysis of Fluid-Conveying Pipes with Periodically Varying Cross-Section

2021 ◽  
Vol 11 (21) ◽  
pp. 10485
Author(s):  
Hao Yu ◽  
Feng Liang ◽  
Yu Qian ◽  
Jun-Jie Gong ◽  
Yao Chen ◽  
...  
Keyword(s):  
Free Vibration ◽  
Band Gap ◽  
Cross Section ◽  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Critical Parameters ◽  
Mode Shapes ◽  
Beam Model ◽  
The Impact ◽  
Fluid Conveying Pipes

Phononic crystals (PCs) are a novel class of artificial periodic structure, and their band gap (BG) attributes provide a new technical approach for vibration reduction in piping systems. In this paper, the vibration suppression performance and natural properties of fluid-conveying pipes with periodically varying cross-section are investigated. The flexural wave equation of substructure pipes is established based on the classical beam model and traveling wave property. The spectral element method (SEM) is developed for semi-analytical solutions, the accuracy of which is confirmed by comparison with the available literature and the widely used transfer matrix method (TMM). The BG distribution and frequency response of the periodic pipe are attained, and the natural frequencies and mode shapes are also obtained. The effects of some critical parameters are discussed. It is revealed that the BG of the present pipe system is fundamentally induced by the geometrical difference of the substructure cross-section, and it is also related to the substructure length and fluid–structure interaction (FSI). The number of cells does not contribute to the BG region, while it has significant effects on the amplitude attenuation, higher order natural frequencies and mode shapes. The impact of FSI is more evident for the pipes with smaller numbers of cells. Moreover, compared with the conventional TMM, the present SEM is demonstrated more effective for comprehensive analysis of BG characteristics and free vibration of PC dynamical structures.

scholarly journals Understanding citation patterns between impact-factor and blacklisted journals

2021 ◽  
Author(s):  
Emanuel Kulczycki ◽  
Marek Hołowiecki ◽  
Zehra Taskin ◽  
Franciszek Krawczyk
Keyword(s):  
Impact Factor ◽  
Web Of Science ◽  
Decision Makers ◽  
Impact Factors ◽  
Predatory Journals ◽  
Subject Categories ◽  
Citation Indexes ◽  
Predatory Publishing ◽  
Number Of Citations ◽  
The Impact

One of the most fundamental issues in academia today is understanding the differences between legitimate and predatory publishing. While decision-makers and managers consider journals indexed in popular citation indexes such as Web of Science or Scopus as legitimate, they use two blacklists (Beall’s and Cabell’s), one of which has not been updated for a few years, to identify predatory journals. The main aim of our study is to reveal the contribution of the journals accepted as legitimate by the authorities to the visibility of blacklisted journals. For this purpose, 65 blacklisted journals in social sciences and 2,338 Web-of-Science-indexed journals that cited these blacklisted journals were examined in-depth in terms of index coverages, subject categories, impact factors and self-citation patterns. We have analysed 3,234 unique cited papers from blacklisted journals and 5,964 unique citing papers (6,750 citations of cited papers) from Web of Science journals. We found that 13% of the blacklisted papers were cited by WoS journals and 37% of the citations were from impact-factor journals. As a result, although the impact factor is used by decision-makers to determine the levels of the journals, it has been revealed that there is no significant relationship between the impact factor and the number of citations to blacklisted journals. On the other hand, country and author self-citation practices of the journals should be considered. All the findings of this study underline the importance of the second part of this study, which will examine the contents of citations to articles published in predatory journals because understanding the motivations of the authors who cited blacklisted journals is important to correctly understand the citation patterns between impact-factor and blacklisted journals.

scholarly journals Uncertainty Measures for Economics Journal Impact Factors

2013 ◽  
Vol 51 (1) ◽  
pp. 173-189 ◽  
Author(s):  
David I Stern
Keyword(s):  
Impact Factor ◽  
Confidence Intervals ◽  
Standard Error ◽  
Impact Factors ◽  
Elite Group ◽  
Economics Journal ◽  
Uncertainty Measures ◽  
Economics Journals ◽  
The Impact ◽  
Journal Impact

Academic economists appear to be intensely interested in rankings of journals, institutions, and individuals. Yet there is little discussion of the uncertainty associated with these rankings. To illustrate the uncertainty associated with citations-based rankings, I compute the standard error of the impact factor for all economics journals with a five-year impact factor in the 2011 Journal Citations Report. I use these to derive confidence intervals for the impact factors as well as ranges of possible rank for a subset of thirty journals. I find that the impact factors of the top two journals are well defined and set these journals apart in a clearly defined group. An elite group of 9–11 mainstream journals can also be fairly reliably distinguished. The four bottom ranked journals are also fairly clearly set apart. For the remainder of the distribution, confidence intervals overlap and rankings are quite uncertain. (JEL A14)

Impact of Consensus Papers versus Randomized Trials in Critical Care Nephrology

2020 ◽  
Vol 49 (6) ◽  
pp. 708-712
Author(s):  
John A. Kellum
Keyword(s):  
Clinical Trials ◽  
Critical Care ◽  
Impact Factor ◽  
Randomized Trials ◽  
Secondary Analysis ◽  
Consensus Conference ◽  
Impact Factors ◽  
Publication Type ◽  
Consensus Conferences ◽  
The Impact

<b><i>Introduction:</i></b> Reports of consensus conferences are usually valued less than reports of clinical trials even when rigorous methodology is used. However, limited data are available comparing the impact of these 2 methods of shaping clinical practice. <b><i>Objective:</i></b> Compare the publication impact of consensus conferences and clinical trials. <b><i>Methods:</i></b> Consensus publications from the Acute Disease Quality Initiative (ADQI) from 2002 through 2017 were identified and classified by subject matter. Randomized trials were identified in the same publication year and subject in journals, starting with the highest impact factor. Both publication types were matched, and total citations were determined for each using Google Scholar. A secondary analysis compared total costs for each publication type. <b><i>Results and Conclusions:</i></b> Seventeen ADQI consensus conference reports and 17 randomized trials were identified. ADQI reports received a similar number of citations per paper (median, interquartile range) compared to randomized trials (132, 54–228; vs. 159, 60–340, <i>p</i> = ns). Similarly, 10 (58.8%) ADQI reports and 10 randomized trials were cited &#x3e;100 times. On average, ADQI reports appeared in journals with lower impact factors compared to clinical trials (5.4 ± 4.6 vs. 25.4 ± 27.1; <i>p</i> &#x3c; 0.01). The median cost per citation (USD 2017) for ADQI reports was USD 606.01 compared to almost twice this figure, USD 1,182.59, for clinical trials on the same topics (<i>p</i> = 0.09). Despite being published in lower impact factor journals, consensus reports on topics in critical care nephrology, received similar citations to randomized controlled trials published the same year.

scholarly journals Comparison of the Impact Factors of the Most-Cited Cardiovascular Journals

2019 ◽  
Vol 124 (12) ◽  
pp. 1718-1724 ◽  
Author(s):  
Tobias Opthof
Keyword(s):  
Impact Factor ◽  
Journal Impact Factor ◽  
European Heart Journal ◽  
The Other ◽  
Impact Factors ◽  
Additional Advantage ◽  
The Right ◽  
Number Of Classes ◽  
The Impact ◽  
Journal Impact

In this article, I show that the distribution of citations to papers published by the top 30 journals in the category Cardiac & Cardiovascular Systems of the Web of Science is extremely skewed. This skewness is to the right, which means that there is a long tail of papers that are cited much more frequently than the other papers of the same journal. The consequence is that there is a large difference between the mean and the median of the citation of the papers published by the journals. I further found that there are no differences between the citation distributions of the top 4 journals European Heart Journal , Circulation , Journal of the American College of Cardiology , and Circulation Research . Despite the fact that the journal impact factor (IF) varied between 23.425 for Eur Heart J and 15.211 for Circ Res with the other 2 journals in between, the median citation of their articles plus reviews (IF Median) was 10 for all 4 journals. Given the fact that their citation distributions were similar, it is obvious that an indicator (IF Median) that reflects this similarity must be superior to the classical journal impact factor, which may indicate a nonexisting difference. It is underscored that the IF Median is substantially lower than the journal impact factor for all 30 journals under consideration in this article. Finally, the IF Median has the additional advantage that there is no artificial ranking of 128 journals in the category but rather an attribution of journals to a limited number of classes with comparable impact.

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