Effect of Friction Coefficients Regarding Bolt Self-Loosening

2020 ◽  
Author(s):  
Yasumasa Shoji
Keyword(s):  
Finite Element ◽  
Torque Control ◽  
Tension Control ◽  
Friction Reduction ◽  
The Other ◽  
Finite Element Analyses ◽  
Bearing Surface ◽  
Friction Coefficients ◽  
Male And Female ◽  
Other Hand

Abstract As there have been many researches for bolt self-loosening and a lot of knowledge have been accumulated, the phenomena has been understood more and more clearly. On the other hand, it is quite difficult to achieve both non-self-loosening and easy bolting tasks. In practical situations, easy and stable bolting is more focused and torque control is employed for tension control in the fields. For the stable bolting, friction of the threads is reduced by lubrication. However, the effect of this friction reduction is not yet investigated in the aspect of self-loosening. In this paper, the effect of frictions between male and female threads and between nut and bearing surface is investigated by FEA simulations. This provides information how self-loosening can be controlled. In this paper, the motion of the fastened plate transverse to the bolt axis is considered. This motion is known as the easiest motion to make self-loosening in experience and also as shown so in the author’s previous researches. The friction seems to increase self-loosening and also decrease self-loosening at the same time. It seems that the friction on the bearing surface drives self-loosening and friction on the thread surfaces prevents it. In this paper, both the frictions are examined in the relative manner with the Finite Element Analyses.

Self-Loosening Behavior of the Nut Due to Tension Change Considering the Inclination of Bearing Surface

2021 ◽  
Author(s):  
Yasumasa Shoji
Keyword(s):  
Finite Element ◽  
Axial Force ◽  
Relative Displacement ◽  
The Self ◽  
The Other ◽  
Transverse Load ◽  
Finite Element Analyses ◽  
Bearing Surface ◽  
Tension Change ◽  
Surface Inclination

Abstract Self-loosening behavior is a topic which many researchers are tackling and the principle is coming clearer. Self-loosening occurs mainly when transverse load is applied to the bolt/nut system and the loosening also occurs when such other loads are applied as impact of the bolt (NAS3350 test type) or temperature difference between bolt and nut. The author reproduced the phenomena by using finite element analyses and found the self-loosening is caused by radial relative displacement between bolt and nut threads. On the other hand, some researchers say the self-loosening occur when the tension changes repeatedly while others say it doesn’t. This axial force phenomenon is not yet clear even in experiment. In this paper, the self-loosening phenomenon by the tension change is examined using Finite Element Analyses. The results show that the self-loosening depends on the inclination of the bearing surface. The loosening does not occur when the inclination of the bearing surface is small enough and it occurs when the inclination is large. As the inclination of the bolt head and nut is allowed within the engineering tolerance and flanges rotate when it fastened making the bolt head or nut bearing surface inclination, the self-loosening may happen for any bolts in nature if tension changes repeatedly.

LANGUAGE USE BETWEEN MALE AND FEMALE HOST IN HITAM PUTIH TALK SHOW

2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Nurmaliana Sari ◽  
Sumarsih Sumarsih ◽  
Busmin Gurning
Keyword(s):  
Language Use ◽  
The Other ◽  
Male And Female ◽  
Talk Show ◽  
Dominant Language ◽  
Other Hand ◽  
Domestic Activities ◽  
Female Host ◽  
Negative Connotation ◽  
Descriptive Qualitative

This study discusses about language use occurred by male and female host in Hitam Putih talk show. The method of this research is descriptive qualitative. The subjects of this study are male and female host in Hitam Putih talk show. The data are the utterances produced by male and female host in Hitam Putih talk show. This research focuses on the show broadcasted on October 2016 by taking 4 videos randomly. The objective of this study is to describe kinds of the language use uttered by male and female host in Hitam Putih talk show. The findings showed that the kinds of language use consist of 6 parts. The dominant language use uttered by male host is expletive, because male’s utterances are frequently stated in a negative connotation. On the other hand, female host utterances are found in specialized vocabulary as the most dominant because female host has more interest in talking family affairs, such as the education of children, clothes, cooking, and fashion, etc. Women also tended to talk about one thing related to the home and domestic activities. However, the representation of language use uttered by male and female are deficit, dominance and different. Keywords: Language Use, Gender, Talk Show

scholarly journals Awareness of dental fluorosis among undergraduate dental students in Riyadh region: a survey based study

2018 ◽  
Vol 6 (12) ◽  
pp. 3852
Author(s):  
Reem AlDaiji ◽  
Malak Alotaibi ◽  
Dania Alnowaiser ◽  
Rawan Albahely ◽  
Rama Bachat ◽  
...  
Keyword(s):  
Dental Caries ◽  
Dental Fluorosis ◽  
Pilot Trial ◽  
Dental Students ◽  
The Other ◽  
Male And Female ◽  
Other Hand ◽  
Structured Questionnaire

Background: Fluoride protects the teeth from dental caries using the needed amount of fluoride products.Methods: A Modified structured questionnaire has been validated through a pilot trial (20 responses) prior to administration that contains16 questions was distributed. Other than the demographics, the data were collected from 500 participants including undergraduate male and female dental students.Results: The majority described the mild fluorosis appearance in the teeth according to Dean’s index appropriately as white opacity of the enamel (64%, n=320). On the other hand, only 31.1% (n=155) and 46% (n=229) described the moderate and severe fluorosis appearance in the teeth according to Dean’s index appropriately.Conclusions: The dissemination and education about dental fluorosis is urgently needed and should be tailored to reach this population. The knowledge about causes of fluoride and the effect on dental fluorosis should be presented in the education.

A Study of the Conservatism in ASME BPVC Section VIII Division 2 Opening Design for External Pressure

2019 ◽  
Author(s):  
Barry Millet ◽  
Kaveh Ebrahimi ◽  
James Lu ◽  
Kenneth Kirkpatrick ◽  
Bryan Mosher
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
External Pressure ◽  
The Other ◽  
Finite Element Analyses ◽  
Division 1 ◽  
Section Viii ◽  
Allowable Compressive Stress ◽  
Division 2

Abstract In the ASME Boiler and Pressure Vessel Code, nozzle reinforcement rules for nozzles attached to shells under external pressure differ from the rules for internal pressure. ASME BPVC Section I, Section VIII Division 1 and Section VIII Division 2 (Pre-2007 Edition) reinforcement rules for external pressure are less stringent than those for internal pressure. The reinforcement rules for external pressure published since the 2007 Edition of ASME BPVC Section VIII Division 2 are more stringent than those for internal pressure. The previous rule only required reinforcement for external pressure to be one-half of the reinforcement required for internal pressure. In the current BPVC Code the required reinforcement is inversely proportional to the allowable compressive stress for the shell under external pressure. Therefore as the allowable drops, the required reinforcement increases. Understandably, the rules for external pressure differ in these two Divisions, but the amount of required reinforcement can be significantly larger. This paper will examine the possible conservatism in the current Division 2 rules as compared to the other Divisions of the BPVC Code and the EN 13445-3. The paper will review the background of each method and provide finite element analyses of several selected nozzles and geometries.

Homophobia Among Social Work and Non-Social Work Students

2002 ◽  
Vol 7 (2) ◽  
pp. 15-32 ◽  
Author(s):  
An-Pyng Sun
Keyword(s):  
Social Work ◽  
Social Work Education ◽  
Social Work Students ◽  
The Other ◽  
Male And Female ◽  
Other Hand ◽  
Work Education

This study compares degree of homophobia between social work and non-social work students. The results show that although social work students are not significantly different from non-social work students in their levels of homophobia, both male and female social work students are significantly less homophobic than male non-social work students. On the other hand, somewhat surprisingly, female social work students are significantly more homophobic than female non-social work students on the issues of whether homosexuality is a sin and whether homosexuality is disgusting. Implications for social work education are discussed.

A Review and Controlled Study of Cutaneous Conditions associated with Lithium Carbonate

1983 ◽  
Vol 143 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Dimocritos Sarantidis ◽  
Brent Waters
Keyword(s):  
Demographic Data ◽  
Lithium Carbonate ◽  
Lithium Therapy ◽  
The Other ◽  
Controlled Study ◽  
Structured Interviews ◽  
Male And Female ◽  
Other Hand ◽  
Family Histories ◽  
First Time

SummaryThis study compares the incidence of a variety of cutaneous conditions among 91 patients treated with lithium carbonate with the incidence of such conditions among 44 patients treated with other non-neuroleptic, maintenance medications. Data on cutaneous conditions and allergies were obtained using structured interviews, demographic data, medication histories and personal and family histories.A significantly greater proportion of the lithium-treated patients than the comparison patients reported a cutaneous condition which may have been secondary to treatment in that it developed for the first time after the medication or appeared to have been exacerbated by the medication. Among the lithium-treated patients, females were found to be significantly more likely to report a secondary cutaneous condition. This effect was found across the whole range of cutaneous conditions. Male lithium-treated patients on the other hand reported approximately the same rate of secondary cutaneous conditions as both male and female comparison patients. Possible reasons for this sexual effect on incidence are discussed.The literature on cutaneous conditions which have been associated with lithium therapy is also reviewed.

scholarly journals Compare of Food Habit and Nutritional Status of Rural Male and Female

2021 ◽  
Vol 8 (10) ◽  
pp. 556-572
Author(s):  
Redwan Rahman ◽  
Mahfuza Khanom Sheema
Keyword(s):  
Nutritional Status ◽  
Eating Habits ◽  
Food Habit ◽  
Lower Class ◽  
The Other ◽  
Male And Female ◽  
Other Hand ◽  
The People ◽  
Different Sources ◽  
North Western

ABSTRACT There is a big difference between male and female in the rural environment of Bangladesh and the aim of this eating habits and nutritional status. The study was conducted through 384 respondents from 9 villages in Ishwardi, Pabna; a north-western district of Bangladesh. The research has done on the food habits of the middle and lower class people of the villages. And some informations are collected from the different sources. In the research 73.44% of male earn more than 24 thousand BDT per month when only 43.32% female are earning more than 24 thousand BDT. Most of the female are housewives and male are service holder. 44.79% male  are service holder on the other hand 4.69% female are service holder. Rice is the main food for Bangladesh. So, most of the people have rice on daily three times. 37.80% of female and 66.98% of male are having rice. Ruti is the second priority food, female take this food 0.56% and male take 7.55% for 2 days. 63.33% female take egg, on the other hand 58.07% male take egg per week.  3.2% female her meal last of all and 1.5% female take it first of all. On the other hand 6.25% male take their meal first of all and 3.39% male take their meal last of all. Most of the female are normal having BMI 89.06% on the other hand male are overweight 78.18%. In the light of the study the eating habits of male and female in Bangladesh have improved but it has not yet affected everyone.          

scholarly journals Children Safety: Education Game for Childs Sex Education

SISFORMA ◽  
2017 ◽  
Vol 3 (2) ◽  
pp. 44
Author(s):  
Fajar As'ari ◽  
Hendra Prasetya ◽  
Ridwan Sanjaya
Keyword(s):  
Sexual Abuse ◽  
Sex Education ◽  
The Other ◽  
Media Education ◽  
Sex Behavior ◽  
Safety Education ◽  
Male And Female ◽  
Important Thing ◽  
Other Hand ◽  
The Way

Some people still cannot talk freely about sex education. On the other hand, some of them have an assumption about teaching sex education will leads to free sex behavior. Sometimes parent afraid to talk about sex education with their children, even some parent think sex education is not important thing for children.However, in fact children need to know about sex education for their own good. To children, sex education is to explain differences in male and female and to know well about themselves. Create media to deliver sex education is the way to teach children about sex education. Among many media, game is one option to deliver this education.This research will discuss about game for childs sex media education. Use game as sex media education because game has capability to deliver message. Through game concept, picture, and animation, game deliver childs sex education to children. With the objective to prevent child from sexual abuse. However, when children play the game they need companion to make clear that children understand the meaning of game message through game story.

scholarly journals Nonlocal vibration of carbon/boron-nitride nano-hetero-structure in thermal and magnetic fields by means of nonlinear finite element method

2020 ◽  
Vol 7 (5) ◽  
pp. 591-602 ◽  
Author(s):  
Hamid M Sedighi ◽  
Mohammad Malikan ◽  
Ali Valipour ◽  
Krzysztof Kamil Żur
Keyword(s):  
Finite Element ◽  
Boron Nitride ◽  
Dynamic Behavior ◽  
Thermal Environment ◽  
Boron Nitride Nanotubes ◽  
Nonlinear Finite Element ◽  
The Other ◽  
Beam Model ◽  
Nonlinear Frequency ◽  
Other Hand

Abstract Hybrid nanotubes composed of carbon and boron-nitride nanotubes have manifested as innovative building blocks to exploit the exceptional features of both structures simultaneously. On the other hand, by mixing with other types of materials, the fabrication of relatively large nanotubes would be feasible in the case of macroscale applications. In the current article, a nonlinear finite element formulation is employed to deal with the nonlocal vibrational behavior of carbon/boron-nitride nano-hetero-tubes in the presence of magneto-thermal environment. Euler–Bernoulli beam model in conjunction with the Eringen’s nonlocal theory of elasticity is adopted to derive the governing equation of motion. In order to conduct a nonlinear frequency analysis, the von-Kármán nonlinearity associated with moderate rotations is also considered. It is well known that temperature gradients can significantly change the dynamic behavior of nanotubes. On the other hand, the coefficients of thermal expansions of carbon and boron-nitride nanotubes are quite different that may affect the structural stability of hybrid nanotubes. Hence, to explore the vibration characteristic of such composite structures, the influence of magneto-thermal environment is also taken into account. Finally, the eigenvalue analysis is performed to exhibit the nonlinear mode shapes and natural frequencies of the system due to initial displacement. It is expected that the recognition of dynamic behavior of such hybrid nanotubes may open the doors to the creative design of next-generation nano-devices.

scholarly journals Preliminary Finite Element Analysis of Locomotive Crashworthy Components

2011 ◽  
Author(s):  
Patricia Llana ◽  
Richard Stringfellow
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Management ◽  
New Technologies ◽  
The Other ◽  
Finite Element Models ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Passenger Trains ◽  
Deformation Modes

The Office of Research and Development of the Federal Railroad Administration (FRA) and the Volpe Center are continuing to evaluate new technologies for increasing the safety of passengers and operators in rail equipment. In recognition of the importance of override prevention in train-to-train collisions in which one of the vehicles is a locomotive, and in light of the success of crash energy management technologies in cab car-led passenger trains, the Volpe Center seeks to evaluate the effectiveness of components that could be integrated into the end structure of a locomotive that are specifically designed to mitigate the effects of a collision and, in particular, to prevent override of one of the lead vehicles onto the other. A research program is being conducted that aims to develop, fabricate and test two crashworthy components for the forward end of a locomotive: (1) a deformable anti-climber, and (2) a push-back coupler. Preliminary designs for these components have been developed. This paper provides details on the finite element models of the crashworthy components and how the component designs behave in the finite element analyses. The component designs will be evaluated to determine if the requirements have been met, such as the energy absorption capability, deformation modes, and force/crush characteristics.

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