scholarly journals An experimental and comparative study of the self-loosening of bolted-joints under cyclic transverse loading

2021 ◽  
Author(s):  
Umut İNCE ◽  
Mustafa GÜDEN
Keyword(s):  
Comparative Study ◽  
The Self ◽  
Bolted Joints ◽  
Transverse Loading

Design of multi-bolted joints to prevent self-loosening failure

2016 ◽  
Vol 230 (15) ◽  
pp. 2564-2578 ◽  
Author(s):  
G Dinger
Keyword(s):  
Automotive Industry ◽  
Development Process ◽  
Design Method ◽  
The Self ◽  
Bolted Joints ◽  
Combined Loading ◽  
Experimental Investigations ◽  
Transverse Loading ◽  
Periodic Load ◽  
Element Analysis

The rotational self-loosening of bolted joints under cyclic loading is a process, which means a screw rotation against the assembly direction by periodic load cycles. Thus, the preload balance is released and the clamping function is no longer maintained. The effect is well known, but prevention is usually performed experimentally only after occurrence of self-loosening events. The paper gives a systematic presentation of the dimensioning and the possibility to consider self-loosening in the development process. The procedure for self-loosening dimensioning and the influences are demonstrated with safety-relevant multi-bolted connections from the automotive industry. The aim of this paper is to provide a numerical design method with finite element analysis for detecting and understanding of the self-loosening process at bolted joints. Another focus of the work is to investigate the self-loosening behaviour under combined loading with a superposition of translation and rotation. Combined loading can lead to self-loosening even before reaching the limit of self-loosening for transverse loading. The computational results of the numerical simulation (FEA) are compared with experimental investigations.

Makna Alif dalam Puisi Zikir D. Zawawi Imron dan Sajak Alif Ahmadun Yosi Herfanda

2020 ◽  
Vol 2 (1) ◽  
pp. 52
Author(s):  
Sholeha Rosalia ◽  
Yosi Wulandari
Keyword(s):  
Comparative Study ◽  
Comparative Method ◽  
The Self ◽  
Sociology Of Literature ◽  
Self Reflection ◽  
The Public ◽  
The Creation

Alif means the first, saying the Supreme Life and is Sturdy and has the element of fire and Alif is formed from Ulfah (closeness) ta'lif (formation). With this letter Allah mementa'lif (unite) His creation with the foundation of monotheism and ma'rifah belief in appreciation of faith and monotheism. Therefore, Alif opens certain meanings and definitions of shapes and colors that are in other letters. Then be Alif as "Kiswah" (clothes) for different messages. That is a will. "IQRO" is a revelation that was first passed down to the Prophet Muhammad. Saw. Read it, which starts with the letter Alif and ends with the letter Alif. The creation of a poem is influenced by the environment and the self-reflection of a poet where according to the poet's origin, in comparing in particular Alif's poetry from the two poets. The object of this research is the poetry of Zikir by D. Zawawi Imron and Sajak Alif by Ahmadun Yosi Herfanda. This study uses a comparative method and sociology of literature. Through a comparative study of literature between the poetry of Zikir D. Zawawi Imron and Sajak Alif Ahmadun Yosi Herfanda, it is hoped that the public can know the meaning of Alif according to the poet's view. With this research, the Indonesian people can accept different views on the meaning of Alif in accordance with their respective understanding without having to look for what is right and wrong. The purpose in Alif is like a life, in the form of letters like a body, a tree that is cut to the root, from the heart is split to the seeds, then from the seeds are split so that nothing is the essence of life. So, it is clear that Alif is the most important and Supreme letter. Talking about the meaning of Alif as the first letter revealed on earth. After the letter Alif was revealed, 28 other Hijaiyah letters were born. The letter Alif is made the beginning of His book and the opening letter. Other letters are from Alif and appear on him.

scholarly journals Comparative Study of Chemosensory Dysfunction in COVID-19 in 2 Geographically Distinct Regions

2021 ◽  
pp. 014556132110001
Author(s):  
Daniel J. Lee ◽  
Daniella Daliyot ◽  
Ri Wang ◽  
Joel Lockwood ◽  
Paul Das ◽  
...  
Keyword(s):  
Comparative Study ◽  
Symptom Onset ◽  
Subgroup Analysis ◽  
Primary Outcome ◽  
Cross Sectional Study ◽  
The Self ◽  
Sectional Study ◽  
Cross Sectional ◽  
Specific Data ◽  
Geographical Regions

Objective: To directly compare the prevalence of chemosensory dysfunction (smell and taste) in geographically distinct regions with the same questionnaires. Methods: A cross-sectional study was performed to evaluate the self-reported symptoms among adults (older than 18 years) who underwent COVID-19 testing at an ambulatory assessment center in Canada and at a hospital in Israel between March 16, 2020, and August 19, 2020. The primary outcome was the prevalence of self-reported chemosensory dysfunction (anosmia/hypomsia and dysgeusia/ageusia). Subgroup analysis was performed to evaluate the prevalence of chemosensory deficits among the outpatients. Results: We identified a total of 350 COVID-19–positive patients (138 Canadians and 212 Israelis). The overall prevalence of chemosensory dysfunction was 47.1%. There was a higher proportion of chemosensory deficits among Canadians compared to Israelis (66.7% vs 34.4%, P < .01). A subgroup analysis for outpatients (never hospitalized) still identified a higher prevalence of chemosensory dysfunction among Canadians compared to Israelis (68.2% vs 36.1%, P < 0.01). A majority of patients recovered their sense of smell after 4 weeks of symptom onset. Conclusion: Although the prevalence of chemosensory deficit in COVID-19 was found to be similar to previously published reports, the prevalence can vary significantly across different geographical regions. Therefore, it is important to obtain regionally specific data so that the symptom of anosmia/dysgeusia can be used as a guide for screening for the clinical diagnosis of COVID-19.

Vibration-Induced Loosening Performance of Preloaded Threaded Fasteners

2010 ◽  
Author(s):  
Xianjie Yang ◽  
Sayed Nassar
Keyword(s):  
Nonlinear Model ◽  
Excitation Amplitude ◽  
The Self ◽  
Transverse Displacement ◽  
Transverse Loading ◽  
Threaded Fasteners ◽  
Bolt Preload ◽  
Proposed Model ◽  
Number Of Cycles ◽  
Insight Into

In an effort to establish a theoretical outline of a criterion for preventing the vibration-induced loosening of preloaded threaded fasteners, this paper provides an experimental and analytical insight into the effect of the initial bolt preload and the excitation amplitude on the self loosening performance of cap screw fastener. A nonlinear model is used for predicting the clamp load loss caused by the vibration-induced loosening of cap screw fasteners under cyclic transverse loading. Experimental verification was conducted on the twisting torque variation and the effect of the preload level and transverse displacement amplitude. Comparison of the experimental and analytical results on the clamp load loss with the number of cycles verifies that the proposed model accurately predicts self-loosening performance.

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