scholarly journals Experimental analysis of the behaviour of different types of joints in the steel structure model subjected to earthquake loading

2021 ◽  
Vol 2070 (1) ◽  
pp. 012227
Author(s):  
T Jaroszewski ◽  
T Falborski ◽  
R Jankowski

Abstract The present paper reports the results of the experimental study performed to investigate the behaviour of two different types of joints (destroyed and welded ones) in the model of the steel structure under seismic excitations. The structure was subjected to three earthquakes, namely Kobe, Loma Prieta and Northridge, using the shaking table investigation. The results obtained from the study indicate that there is a significant difference between the behaviour of destroyed joints and welded ones. It was concluded that the destroyed joints experience higher acceleration than the welded joints during different earthquakes.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ramutis Bansevicius ◽  
Dalius Mazeika ◽  
Vytautas Jurenas ◽  
Genadijus Kulvietis ◽  
Vytautas Bakanauskas

The paper covers the research and development of piezoelectric traveling wave actuators using different types of the waveguides. The introduced piezoelectric actuators can be characterized by specific areas of application, different resolution, and torque. All presented actuators are ultrasonic resonant devices and they were developed to increase amplitudes of the traveling wave oscillations of the contact surface. Three different waveguides are introduced, that is, symmetrical, asymmetrical, and cone type waveguide. A piezoelectric ring with the sectioned electrodes is used to excite traveling wave oscillations for all actuators. Operating principle, electrode pattern, and excitation regimes of piezoelectric actuators are described. A numerical modelling of the actuators was performed to validate the operating principle and to calculate trajectories of the contact points motion. Prototype actuators were made and experimental study was performed. The results of numerical and experimental analysis are discussed.


2020 ◽  
Vol 148 (5-6) ◽  
pp. 350-356
Author(s):  
Anisa Gradascevic ◽  
Ivan Soldatovic ◽  
Anes Joguncic ◽  
Miroslav Milosevic ◽  
Nermin Sarajlic

Introduction/Objective. Gunshot residue (GSR) on the skin of a victim are important evidence, with far better precision, for reconstructive questions in the forensic investigation of cases involving gunshot wounds. The aim of this experimental study was to analyze if there was any significant difference in macroscopic characteristics of wounds that were caused with different types of weapons from three different distances. Methods. This study was conducted at the Department of Ballistic and Mechanoscopic Expertise, Federal Police Directorate. Experiments were done on pigskin and 55 samples were made. Shooting was conducted using a system for safe firing. Samples of the pigskin were shot by firing projectiles from four different weapons and from three different distances, (contact wound, five centimetres and 10 centimetres). Results. At the contact range, wounds caused by automatic rifle had horizontal, vertical diameters larger than those made by pistols. Diameters on the wounds that were caused with different pistols, were similar. At the range of five centimetres, the narrowest part of contusion ring significantly differs even through pistol wounds. Diameters at the range of 10 centimetres are in favor of these results. Gunpowder residue scattering area was statistically different depending of type of weapon (p = 0.004). Conclusion. Wound diameters and surface area are useful for differentiation between pistol and rifle caused wounds. It is unsecure method for determination of pistol caliber or fire range. GSR have much greater potential for future analyses, but even GSR cannot be used to determine pistol caliber.


2012 ◽  
Vol 38 (6) ◽  
pp. 677-685 ◽  
Author(s):  
Mansoor Rismanchian ◽  
Mahnaz Hatami ◽  
Hamid Badrian ◽  
Navid Khalighinejad ◽  
Hossein Goroohi

A microgap between implant and abutment can lead to mechanical and biological problems such as abutment screw fracture and peri-implantitis. The aim of this study was to evaluate microgap size and microbial leakage in the connection area of 4 different abutments to ITI implants. In this experimental study, 36 abutments in 4 groups (including Cast On, Castable, Solid, and Synocta abutments) connected to Straumann fixtures (with their inner part inoculated with bacterial suspension) and microbial leakage were assessed at different times. The size of the microgap in 4 randomized locations was then measured by scanning electron microscope. The data were analyzed by SPSS software and by 1-way variance statistical test, Kruskal-Wallis, and their supplementary tests (Mann-Whitney HSD and Tukey's; α = .05) at the next step. The effect of using different types of abutments was significant on the mean microgap size (P < .001) and on the mean number of leaked colonies (CFU/mL) through the connection area of the implant and abutment within the first 5 hours of the experiment (P = .012); however, it did not significantly influence microleakage at 24 hours, 48 hours, and 14 days (P = .145). Using Synocta abutments compared with Solid abutments will not provide us with more accommodation, and vice versa. Using Solid and Synocta abutments can significantly decrease the microgap size; however, Cast On abutments do not show a significant difference in terms of microgap compared with Castable abutments. Microleakage in the connection area is comparable for these 4 abutments.


2020 ◽  
Author(s):  
Hua Jin ◽  
Lina Jia ◽  
Xiaojuan Yin ◽  
Shilin Wei ◽  
Guiping Xu

Misinformation often continues to influence people’s cognition even after corrected (the ‘continued influence effect of misinformation’, the CIEM). This study investigated the role of information relevance in the CIEM by questionnaire survey and experimental study. The results showed that information with higher relevance to the individuals had a larger CIEM, indicating a role of information relevance in the CIEM. Personal involvement might explain the effects of information relevance on the CIEM. This study provides insightful clues for reducing the CIEM in different types of misinformation and misinformation with varying relevance.


2018 ◽  
Vol 2 (1) ◽  
pp. 29-36
Author(s):  
Ali Muhammad ◽  
Zahoor Ul Haq ◽  
Imad Khan

This study uses Pakistan Social and Living Measurement Survey 2016 to study gender discrimination in school enrollment across the four provinces of Pakistan using bi-variate analysis. Results show that there is highly significant difference between male and female education in rural areas (x^2=4940.50 and p<0.05). Analysis indicate that gender disparity in enrollment is significantly higher in low income households (x^2=115.468 and P<0.05). The study also showed that as compared to male, fewer female are enrolled in both public and private sectors. Hence, socio-economic factors play important role in making decision about children enrollment in different types of school. The study recommends that government to take appropriate steps to reduce gender discrimination in school enrollment by offering subsidy on female education in the country.


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