The application of p-version FEM to gear teeth peak stress valuation

1988 ◽  
Vol 5 (4) ◽  
pp. 170-176 ◽  
Author(s):  
A Pidello ◽  
P.P Strona ◽  
F.A Raffa
Keyword(s):  
Peak Stress ◽  
Gear Teeth

scholarly journals Compliance and Stress Sensitivity of Spur Gear Teeth

1981 ◽  
Vol 103 (2) ◽  
pp. 447-459 ◽  
Author(s):  
R. W. Cornell
Keyword(s):  
Closed Form Solution ◽  
Time History ◽  
Peak Stress ◽  
Spur Gear ◽  
Stress Sensitivity ◽  
Form Solution ◽  
Sensitivity Analyses ◽  
Spur Gears ◽  
Contact Ratio ◽  
Gear Teeth

The magnitude and variation of tooth pair compliance with load position affects the dynamics and loading significantly, and the tooth root stressing per load varies significantly with load position. Therefore, the recently developed time history, interactive, closed form solution for the dynamic tooth loads for both low and high contact ratio spur gears [1] was expanded to include improved and simplified methods for calculating the compliance and stress sensitivity for three involute tooth forms as a function of load position. The compliance analysis is based on Weber [2] and O’Donnell [3] but with an improved fillet/foundation compliance analysis. The stress sensitivity analysis is a modified version of the Heywood method [4] but with an improvement in the magnitude and location of the peak stress in the fillet. These improved compliance and stress sensitivity analyses are presented along with their evaluation using test, finite element, and analytic transformation results, which showed good agreement.

Damage on Roller Bearing Races and Gear Teeth – Classification and Methods of Analysis

2017 ◽  
Vol 54 (7) ◽  
pp. 469-484
Author(s):  
F. Ahrens ◽  
H. Oelschner ◽  
F. M. Ahrens
Keyword(s):  
Roller Bearing ◽  
Gear Teeth ◽  
Methods Of Analysis

Quasi-static Compressive Properties and Behavior of Single-cell Miura Origami Column Fabricated by 3D Printed PLA Material

2020 ◽  
Vol 3 (2) ◽  
pp. 66-73
Author(s):  
Farid Triawan ◽  
Geraldy Cahya Denatra ◽  
Djati Wibowo Djamari
Keyword(s):  
Single Cell ◽  
Peak Stress ◽  
Absorption Capacity ◽  
Compression Tests ◽  
Compressive Properties ◽  
Folding Pattern ◽  
Column Structure ◽  
Thin Walled ◽  
And Behavior ◽  
Initial Peak

The study of a thin-walled column structure has gained much attention due to its potential in many engineering applications, such as the crash box of a car. A thin-walled square column usually exhibits high initial peak force, which may become very dangerous to the driver or passenger. To address this issue, introducing some shape patterns, e.g., origami folding pattern, to the column may become a solution. The present work investigates the compressive properties and behavior of a square box column structure which adopts the Miura origami folding pattern. Several test pieces of single-cell Miura origami column with varying folding angle and layer height are fabricated by a 3D printer. The filament is made of Polylactic Acid (PLA), which is a brittle material. Then, compression tests are carried out to understand its compressive mechanical properties and behavior. The results show that introducing a Miura origami pattern to form a thin-walled square column can dramatically lower down the initial peak stress by 96.82% and, at the same time, increase its ductility, which eventually improves the energy absorption capacity by 61.68% despite the brittle fracture behavior.

Flexible and Wearable GRF and EMG Sensors Enabled Locomotion Mode Recognition for IoHT Based In-home Rehabilitation

2020 ◽  
Author(s):  
Chaoming Fang ◽  
Yixuan Wang ◽  
Shuo Gao
Keyword(s):  
Sensitive Element ◽  
Small Volume ◽  
Peak Stress ◽  
Higher Learning ◽  
Force Sensing ◽  
Sensing System ◽  
Mode Recognition ◽  
Locomotion Mode ◽  
Stress Sensing ◽  
Manipulation Process

In order to quantify the manipulation process of acupuncture, in this article, a piezoelectric glove based wearable stress sensing system is presented. Served as the sensitive element with small volume and high tensile resistance, PVDF greatly meet the need of quantitative analysis. Through piezoelectric force sensing glove, the system is capable of detecting both perpendicular stress as well as shear stress. Besides, key parameters including peak stress at needle are detected and extracted, potentially allowing for a higher learning efficiency hence advancing the development of acupuncture.

Meshing and Bearing Analysis of Nutation Drive with Face Gear

2020 ◽  
Vol 13 (4) ◽  
pp. 352-365
Author(s):  
Guangxin Wang ◽  
Lili Zhu ◽  
Peng Wang ◽  
Jia Deng
Keyword(s):  
Contact Stress ◽  
High Efficiency ◽  
Transmission Ratio ◽  
Contact Strength ◽  
Hertz Contact ◽  
Face Gear ◽  
Compact Structure ◽  
Gear Teeth ◽  
Gear Drive ◽  
Number Of Teeth

Background: Nutation drive is being extensively investigated due to its ability to achieve a high reduction ratio with a compact structure and the potential for low vibration, high efficiency and design flexibility. However, many problems including the difficulty to process the inner bevel gear, less number of teeth in engagement and not being suitable for high-power transmission have restricted its development. Objective: The purpose of this paper is to analyze the contact strength of a patent about a new nutation drive developed based on meshing between two face gears, which has the advantages of both face gear and nutation drive, including large transmission ratio, large coincidence, small size, compact structure and strong bearing capacity. Methods: Based on the meshing principle and basic structure of the nutation face gear drive, the contact strength of nutation face gear transmission is analyzed by the Hertz contact analysis method and FEM method. Results: The maximum stress values of nutation face gear teeth are compared by two methods, which verify the accuracy of Hertz contact analytical method in calculating the contact strength of nutation face gear teeth. Furthermore, nine groups of three-dimensional models for the nutation face gear drive with a transmission ratio of 52 and different cutter parameters are established. Conclusion: The study analyzes the contact stress of fixed and rotary face gears in meshing with planetary face gears, and obtains the distribution law of contact stress and the influence of the number of teeth and parameters of the cutter on the load-carrying capacity.

scholarly journals An Extension Strain Type Mohr–Coulomb Criterion

2021 ◽  
Author(s):  
Manfred Staat
Keyword(s):  
Failure Modes ◽  
Peak Stress ◽  
Fracture Initiation ◽  
Failure Surface ◽  
Confining Pressure ◽  
Biaxial Compression ◽  
Simple Extension ◽  
Strain Criterion ◽  
Shear Component ◽  
Extension Strain

AbstractExtension fractures are typical for the deformation under low or no confining pressure. They can be explained by a phenomenological extension strain failure criterion. In the past, a simple empirical criterion for fracture initiation in brittle rock has been developed. In this article, it is shown that the simple extension strain criterion makes unrealistic strength predictions in biaxial compression and tension. To overcome this major limitation, a new extension strain criterion is proposed by adding a weighted principal shear component to the simple criterion. The shear weight is chosen, such that the enriched extension strain criterion represents the same failure surface as the Mohr–Coulomb (MC) criterion. Thus, the MC criterion has been derived as an extension strain criterion predicting extension failure modes, which are unexpected in the classical understanding of the failure of cohesive-frictional materials. In progressive damage of rock, the most likely fracture direction is orthogonal to the maximum extension strain leading to dilatancy. The enriched extension strain criterion is proposed as a threshold surface for crack initiation CI and crack damage CD and as a failure surface at peak stress CP. Different from compressive loading, tensile loading requires only a limited number of critical cracks to cause failure. Therefore, for tensile stresses, the failure criteria must be modified somehow, possibly by a cut-off corresponding to the CI stress. Examples show that the enriched extension strain criterion predicts much lower volumes of damaged rock mass compared to the simple extension strain criterion.

scholarly journals Effect of peak stress and deformation history on the dynamic tensile behavior of a dual phase steel

2020 ◽  
Author(s):  
J.P. Escobedo ◽  
A.A.H. Ameri ◽  
M. Gonzales ◽  
R. Miller ◽  
H. Wang ◽  
...  
Keyword(s):  
Dual Phase Steel ◽  
Peak Stress ◽  
Tensile Behavior ◽  
Dual Phase ◽  
Deformation History ◽  
Stress And Deformation

Prognostic value of peak stress cardiac power in patients with normal ejection fraction undergoing exercise stress echocardiography

2020 ◽  
Author(s):  
Vidhu Anand ◽  
Garvan C Kane ◽  
Christopher G Scott ◽  
Sorin V Pislaru ◽  
Rosalyn O Adigun ◽  
...  
Keyword(s):  
Ejection Fraction ◽  
Stress Echocardiography ◽  
Stress Test ◽  
Peak Stress ◽  
Left Ventricular ◽  
Exercise Stress ◽  
Cardiac Power ◽  
Exercise Stress Echocardiography ◽  
Lv Mass

Abstract Aims  Cardiac power is a measure of cardiac performance that incorporates both pressure and flow components. Prior studies have shown that cardiac power predicts outcomes in patients with reduced left ventricular (LV) ejection fraction (EF). We sought to evaluate the prognostic significance of peak exercise cardiac power and power reserve in patients with normal EF. Methods and results  We performed a retrospective analysis in 24 885 patients (age 59 ± 13 years, 45% females) with EF ≥50% and no significant valve disease or right ventricular dysfunction, undergoing exercise stress echocardiography between 2004 and 2018. Cardiac power and power reserve (developed power with stress) were normalized to LV mass and expressed in W/100 g of LV myocardium. Endpoints at follow-up were all-cause mortality and diagnosis of heart failure (HF). Patients in the higher quartiles of power/mass (rest, peak stress, and power reserve) were younger and had higher peak blood pressure and heart rate, lower LV mass, and lower prevalence of comorbidities. During follow-up [median 3.9 (0.6–8.3) years], 929 patients died. After adjusting for age, sex, metabolic equivalents (METs) achieved, ischaemia/infarction on stress test results, medication, and comorbidities, peak stress power/mass was independently associated with mortality [adjusted hazard ratio (HR), highest vs. lowest quartile, 0.5, 95% confidence interval (CI) 0.4–0.6, P < 0.001] and HF at follow-up [adjusted HR, highest vs. lowest quartile, 0.4, 95% CI (0.3, 0.5), P < 0.001]. Power reserve showed similar results. Conclusion  The assessment of cardiac power during exercise stress echocardiography in patients with normal EF provides valuable prognostic information, in addition to stress test findings on inducible myocardial ischaemia and exercise capacity.

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