Wear Calculation for Toroidal Drive

2005 ◽  
Vol 128 (4) ◽  
pp. 820-823 ◽  
Author(s):  
Lizhong Xu ◽  
Zhen Huang

In this paper, by analyzing relative motion relationship of the toroidal drive, the lengths of the sliding arc and the rolling arc of the stator, worm, and planet are given. The formulas of the sliding ratios of the stator, worm, and planet teeth surfaces are introduced. The formulas of the wear values of teeth surfaces of the stator, worm, and planet for the drive are proposed. Using the formulas, distributions of the wear values of the stator, worm, and planet teeth surfaces are calculated and influences of the principal parameters of the drive on the wear values are discussed. Test results are close to calculating the value of the above wear equation.

2020 ◽  
Vol 14 (1) ◽  
pp. 45-60
Author(s):  
Yashinta Yashinta ◽  
Dwi Hurriyati

This study aims to determine the relationship of loneliness with problematic internet use on boarding students on Silaberanti street in Siantan jaya Opposite Ulu 1 Palembang city. Research subjects numbered 220 people using random sampling methods. Data was collected using a 60 item problematic internet use scale and a 60 item loneliness. Realibility is generated on scale of problematic internet use of 0,955 and loneliness of 0,946.Hypothesis testing uses product moment correlation analysis techniques. Hypothesis test results showed a positive relationshif between loneliness with problematic internet use on boarding students on Silaberanti street in Siantan jaya Opposite Ulu 1 Palembang city r= 0,684 with a significance level of 0,000 (p<0,01). Loneliness in this study made an effective contribution of 46,8% to problematic internet use which can be seen from the coefficient of determination (r²) that is equel to 0,468.


2021 ◽  
pp. 136943322110015
Author(s):  
Ting Guo ◽  
Na Yang ◽  
Huichun Yan ◽  
Fan Bai

This study aimed to investigate the moment carrying behavior of typical Tibetan timber beam-column joints under monotonic vertical static load and also evaluate the influence of length ratio of Gongmu to beam (LRGB) and dowels layout on the structural performance of the joint. Six full-scale specimens were fabricated with same construction but different Gongmu length and dowels position. The moment carrying performance of beam-column joints in terms of failure mode, moment resistance, and rotational stiffness of joints were obtained via monotonic loading tests. Test results indicated that all joints are characterized by compressive failure perpendicular to grain of Ludou. Additionally, it was found that greater LRGB leads to greater initial rotational stiffness and maximum moment of the joint by an increase of restraint length for beam end; however, offsetting dowels toward column resulted smaller stiffness and ultimate bending moment of joints, particularly, offsetting Beam-Gongmu dowels toward column changed the moment-rotation curve pattern of the beam-column joint, accompanied by a hardening stiffness at last phase. Furthermore, a simplified trilinear model was proposed to represent the moment-rotation relationship of the typical Tibetan timber beam-column joint.


Tribologia ◽  
2021 ◽  
Vol 295 (1) ◽  
pp. 21-26
Author(s):  
Mariusz Opałka ◽  
Wojciech Wieleba ◽  
Angelika Radzińska

The resistance during the frictional interaction of polymeric materials with metallic materials is characterized by a significant dependence on the dynamics of the motion inputs. In a metal-polymer friction pair, the static friction resistance during standstill under load depends on the rate of growth of the force causing the relative motion. Tribological tests of selected (polymer-metal) sliding pairs were carried out. The selected polymers were polyurethane (TPU), polysulfone (PSU), and silicone rubber (SI). They interacted with a pin made of normalized C45 steel under unitary pressure p = 0.5 MPa in dry friction conditions at different gradients of the force driving the relative motion (dF/dt = 0.1-20 [N/s]). The static friction coefficient of the selected sliding pairs was determined on the basis of the recorded static friction force values. The test results show a significant influence of the rate of increase in the motion driving force on the values of static friction resistance. This is mainly due to the viscoelastic properties of polymers.


2019 ◽  
Vol 3 (5) ◽  
pp. 815-826 ◽  
Author(s):  
James Day ◽  
Preya Patel ◽  
Julie Parkes ◽  
William Rosenberg

Abstract Introduction Noninvasive tests are increasingly used to assess liver fibrosis and determine prognosis but suggested test thresholds vary. We describe the selection of standardized thresholds for the Enhanced Liver Fibrosis (ELF) test for the detection of liver fibrosis and for prognostication in chronic liver disease. Methods A Delphi method was used to identify thresholds for the ELF test to predict histological liver fibrosis stages, including cirrhosis, using data derived from 921 patients in the EUROGOLF cohort. These thresholds were then used to determine the prognostic performance of ELF in a subset of 457 patients followed for a mean of 5 years. Results The Delphi panel selected sensitivity of 85% for the detection of fibrosis and &gt;95% specificity for cirrhosis. The corresponding thresholds were 7.7, 9.8, and 11.3. Eighty-five percent of patients with mild or worse fibrosis had an ELF score ≥7.7. The sensitivity for cirrhosis of ELF ≥9.8 was 76%. ELF ≥11.3 was 97% specific for cirrhosis. ELF scores show a near-linear relationship with Ishak fibrosis stages. Relative to the &lt;7.7 group, the hazard ratios for a liver-related outcome at 5 years were 21.00 (95% CI, 2.68–164.65) and 71.04 (95% CI, 9.4–536.7) in the 9.8 to &lt;11.3 and ≥11.3 subgroups, respectively. Conclusion The selection of standard thresholds for detection and prognosis of liver fibrosis is described and their performance reported. These thresholds should prove useful in both interpreting and explaining test results and when considering the relationship of ELF score to Ishak stage in the context of monitoring.


2007 ◽  
Vol 353-358 ◽  
pp. 868-873 ◽  
Author(s):  
Min Hao Zhu ◽  
Zhong Rong Zhou

A complex relative motion of fretting combined by dual motions of radial and tangential fretting was achieved on a modified fretting tester. The composite fretting motion was induced by the action of an oscillating normal force in a sphere-on-inclined flat contact (52100 steel ball against 2091 aluminum alloy). Two types of inclined angles (45° and 60°) were used in the tests. Variations of veridical force vs displacement have been recorded and analyzed as a function of cycles. Effects of the cyclic normal force and the inclined angle were discussed. The test results showed that wear, cracking and plastic deformation accumulation with a strong dissymmetry in damage morphology was observed. A transformation of fretting mode from composite to radial fretting mode occurred due to a strong modification at local contact configuration. As a conclusion, a physical model for wear mechanism of composite fretting was presented.


2020 ◽  
Vol 11 (1) ◽  
pp. 110-119
Author(s):  
Julianto Julianto ◽  
Izma Daud ◽  
Sari Milyati

Abstrak  Latar Belakang :Access block adalah situasi dimana pasien yang mengalami lama rawat di IGD 6 karena kurangnya akses ke ruang rawat inap dan kepadatan jumlah pasien yang tidak terkendali, dampaknya ditemukan bahwa semakin lama access block  semakin tinggi pula perburukan pasien dalam 24 jam.Tujuan : ini bertujuan untuk mengetahui hubungan access block dengan perburukan kondisi pasien di Instalasi Gawat Darurat RSUD Ulin Banjarmasin.Metode :Penelitian menggunakan desain analitik dengan pendekatan cross sectional. Jumlah sampel yang diambil berjumlah 40 orang dengan teknik pengambilan accidental sampling. Analisis data melalui uji spearman rank.Hasil : Hasil uji dipapatkan nilai p hitung 0,000 (0,05) ada hubungan antara access block dengan perburukan kondisi pasien di instalasi gawat darurat RSUD Ulin Banjarmasi.Simpulan: Berdasarka hasil penelitian Ada hubungan antara access block dengan perburukan kondisi pasien di Instalasi Gawat Darurat RSUD Ulin Banjarmasin dengan nilai P= 0,000 nilai α = 0,05 dengan nilai koefisien korelasi 0,588 Kata kunci: Access Block, Perburukan Pasien. Abstract Background :Access block is a situation where patients who experience length of stay in the ED 6 due to lack of access to the inpatient room and uncontrolled density of patients, it is found that the longer the access block the higher the deterioration of patients in 24 hours.Purpose: This study aims to determine the relationship of access block with deteriorating condition of patients in Emergency Installation Ulin Hospital Banjarmasin.Method : The research method uses an analytical design with a cross sectional approach. The number of samples taken is 40 people using the accidental sampling technique. Data analysis through spearman rank test.Result: The test results obtained p value calculated 0,000 (0.05) there is a relationship between the access block and deterioration of the patient's condition at the Ulin Banjarmasin Hospital emergency department.Conclusion: Based on the results of the study, there is a relationship between the access block and the worsening of the patient's condition at the Emergency Department of RSUD Ulin Banjarmasin with a value of P = 0.000 value α = 0.05 with a correlation coefficient value of 0.588. Keywords: Access Block, Patient worsening 


2011 ◽  
Vol 243-249 ◽  
pp. 2050-2054 ◽  
Author(s):  
Pei Hsun Tsai ◽  
Sheng Huoo Ni

In this paper the dynamic property (shear modulus and damping ratio) of cement-stabilized soil is studied with using the resonant column test. The amount of cement admixed, the magnitude of confining pressure, and shearing strain amplitude are the parameters considered. Test results show that the maximum shear modulus of cement-stabilized soil increases with increasing confining pressure, the minimum damping ratio decreases with increasing confining pressure. The shear modulus of cement-stabilized soil decreases with increasing shearing strain while the damping ratio increases with increasing shearing strain. In the paper the relationship of shear modulus versus shearing strain is fitted into the Ramberg-Osgood equations using regression analysis.


2019 ◽  
Vol 801 ◽  
pp. 410-415
Author(s):  
Preda Pichayapan ◽  
Phittayoot Chaleonpan ◽  
Peerapong Jitsangiam ◽  
Pongsakorn Wongchana

Aggregates which are the main component of asphalt concrete play a major role in loading transfer and skid resistant performance of asphalt concrete. Therefore, reduction in friction resistance of aggregate would lead to a decrease in overall skid resistance of asphalt concrete which is a commonly used road pavement surface material. This research aims to evaluate relationship of aggregate friction capacity through the polished stone value and asphalt concrete skid resistance. In this study, a series of polished stone value tests on the study aggregate of limestone and sandy mudstone and British pendulum tests for skid resistance value of polished hot mix asphalt (HMA) slab. An accelerated polishing machine was used to create reduction of skid resistance of HMA slabs. Test results showed that reduction of polished stone value (PSV) of limestone 47.6% leads to a decrease of skid resistance value (SRV) approximately 43.8% of HMA slabs. Furthermore, 14.5% reduction of PSV of sandy mudstone causes a decrease of 20.3% SRV of HMA slabs. Finally, a relationship linear regression between PSV of aggregates and SRV of HMA slab was established.


2013 ◽  
Vol 639-640 ◽  
pp. 796-802
Author(s):  
Yin Hui Qin ◽  
Wen Ji Liu ◽  
Chao Yang Zhou ◽  
Fu Hua Liu

The beam-column joints play a key role in composite steel and concrete structures. In order to ensure a safe design of a new building and obtain optimum design, an experimental program consisting of the tests of three connections with different connection details under low-cyclic reversed loading, A series of mechanical performance such as the stress-strain relationship of steel beam web, beam flange, connecting plate, bracket web, bracket flange, distributing steel, concealed column in node core area are all analyzed, the results show that in the loading process, steel beam flange and web ,bracket flange produced yield deformation, but the bracket web, distributing steel, concealed column didn’t yield, so the steel beam flange and web, bracket flange must be strengthened in the design. The test results also show that the bracket can be regarded as canlitecver model in practical engineering.


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