Contact Stress for Toroidal Drive

2003 ◽  
Vol 125 (1) ◽  
pp. 165-168 ◽  
Author(s):  
Lizhong Xu ◽  
Zhen Huang ◽  
Yulin Yang
Keyword(s):  
Elastic Deformation ◽  
Contact Stress ◽  
Load Distribution ◽  
Contact Stresses ◽  
Periodic Change ◽  
Stress Distributions ◽  
Contact Strength ◽  
Optimal Parameters ◽  
Pair Number

Considering the elastic deformation of the rotor and the periodic change of the mesh teeth pair number, the calculation equations of the load distribution for the toroidal drive are presented. Based on the equations, the formulas for calculation of the contact stresses among stator and worm are introduced. By using the above-mentioned formulas, the contact stress distributions for the drive are obtained. The optimal parameters providing for equal contact strength of the stator and worm are determined. These results are useful in manufacture and design of the drive.

Evaluating Measured Tire Contact Stresses to Predict Pavement Response and Performance

2000 ◽  
Vol 1716 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Reynaldo Roque ◽  
Leslie Ann Myers ◽  
Bjorn Birgisson
Keyword(s):  
Contact Stress ◽  
Contact Stresses ◽  
Embedded Sensors ◽  
Stress Distributions ◽  
Near Surface ◽  
Weak Bases ◽  
Truck Tires ◽  
Pavement Response ◽  
Pavement Structures ◽  
And Performance

Recent research has indicated that measured contact stress distributions under radial truck tires are highly complex. These stress distributions help to explain near-surface distresses that have become more prevalent since the inception of radial tires, indicating that realistic contact stresses must be considered when pavement response and performance are evaluated. However, because of the complexities involved in measuring contact stresses under tires, obtaining these measurements directly on real pavements is not possible. Consequently, contact stress measurements have been made on systems having rigid foundations with embedded sensors. Therefore, determining whether tire contact stresses measured on a rigid foundation are significantly different from contact stresses under the same tire on an actual pavement is critical. Finite element analyses conducted indicated that both vertical and lateral tire contact stresses measured on rigid foundations accurately represent the contact stresses for the same tire on typical asphalt pavement structures. Some minor differences were observed for thin (50-mm surface) pavements on weak bases, but the correspondence in terms of both distribution and magnitude was still very good. The conclusion was that contact stresses measured by devices with rigid foundations appear to be suitable for predicting response and performance of highway pavements.

Personalized Fiber-Reinforcement Networks for Meniscus Reconstruction

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Jay M. Patel ◽  
Andrzej Brzezinski ◽  
Salim A. Ghodbane ◽  
Rae Tarapore ◽  
Tyler M. Lu ◽  
...  
Keyword(s):  
Contact Stress ◽  
Load Distribution ◽  
Fiber Reinforcement ◽  
Distribution Analysis ◽  
Stress Distributions ◽  
Fiber Network ◽  
Fiber Networks ◽  
Length Width ◽  
Post Traumatic

Abstract The menisci are fibrocartilaginous tissues that are crucial to the load-sharing and stability of the knee, and when injured, these properties are compromised. Meniscus replacement scaffolds have utilized the circumferential alignment of fibers to recapitulate the microstructure of the native meniscus; however, specific consideration of size, shape, and morphology has been largely overlooked. The purpose of this study was to personalize the fiber-reinforcement network of a meniscus reconstruction scaffold. Human cadaveric menisci were measured for a host of tissue (length, width) and subtissue (regional widths, root locations) properties, which all showed considerable variability between donors. Next, the asymmetrical fiber network was optimized to minimize the error between the dimensions of measured menisci and predicted fiber networks, providing a 51.0% decrease (p = 0.0091) in root-mean-square (RMS) error. Finally, a separate set of human cadaveric knees was obtained, and donor-specific fiber-reinforced scaffolds were fabricated. Under cyclic loading for load-distribution analysis, in situ implantation of personalized scaffolds following total meniscectomy restored contact area (253.0 mm2 to 488.9 mm2, p = 0.0060) and decreased contact stress (1.96 MPa to 1.03 MPa, p = 0.0025) to near-native values (597.4 mm2 and 0.83 MPa). Clinical use of personalized meniscus devices that restore physiologic contact stress distributions may prevent the development of post-traumatic osteoarthritis following meniscal injury.

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.

Thermomechanical Coupling of a Hyper-viscoelastic Truck Tire and a Pavement Layer and its Impact on Three-dimensional Contact Stresses

2021 ◽  
pp. 036119812110171
Author(s):  
Angeli Jayme ◽  
Imad L. Al-Qadi
Keyword(s):  
Contact Stress ◽  
Contact Area ◽  
Three Dimensional ◽  
Interaction Model ◽  
Rolling Resistance ◽  
Contact Stresses ◽  
Thermomechanical Coupling ◽  
Temperature Profiles ◽  
Near Surface ◽  
Truck Tire

A thermomechanical coupling between a hyper-viscoelastic tire and a representative pavement layer was conducted to assess the effect of various temperature profiles on the mechanical behavior of a rolling truck tire. The two deformable bodies, namely the tire and pavement layer, were subjected to steady-state-uniform and non-uniform temperature profiles to identify the significance of considering temperature as a variable in contact-stress prediction. A myriad of ambient, internal air, and pavement-surface conditions were simulated, along with combinations of applied tire load, tire-inflation pressure, and traveling speed. Analogous to winter, the low temperature profiles induced a smaller tire-pavement contact area that resulted in stress localization. On the other hand, under high temperature conditions during the summer, higher tire deformation resulted in lower contact-stress magnitudes owing to an increase in the tire-pavement contact area. In both conditions, vertical and longitudinal contact stresses are impacted, while transverse contact stresses are relatively less affected. This behavior, however, may change under a non-free-rolling condition, such as braking, accelerating, and cornering. By incorporating temperature into the tire-pavement interaction model, changes in the magnitude and distribution of the three-dimensional contact stresses were manifested. This would have a direct implication on the rolling resistance and near-surface behavior of flexible pavements.

THREE-DIRECTIONAL CONTACT STRESS DISTRIBUTIONS FOR A PNEUMATIC TRACTOR TIRE IN SOFT SOIL

1998 ◽  
Vol 41 (5) ◽  
pp. 1237-1242 ◽  
Author(s):  
H. Jun ◽  
T. Kishimoto ◽  
T. R. Way ◽  
T. Taniguchi
Keyword(s):  
Contact Stress ◽  
Soft Soil ◽  
Stress Distributions

scholarly journals Contact stress distributions on the femoral head of the emu (Dromaius novaehollandiae)

2009 ◽  
Vol 42 (15) ◽  
pp. 2495-2500 ◽  
Author(s):  
Karen L. Troy ◽  
Thomas D. Brown ◽  
Michael G. Conzemius
Keyword(s):  
Femoral Head ◽  
Contact Stress ◽  
Stress Distributions ◽  
Dromaius Novaehollandiae

Measurement of the Interfacial Stresses in Rolling Using the Elastic Deformation of the Roll

1987 ◽  
Vol 109 (4) ◽  
pp. 362-369 ◽  
Author(s):  
D. J. Meierhofer ◽  
K. A. Stelson
Keyword(s):  
Elastic Deformation ◽  
Normal Pressure ◽  
New Method ◽  
Frictional Stress ◽  
Stress Distributions ◽  
Strain Gages ◽  
Experimental Rolling ◽  
Mechanical Isolation ◽  
Roll Gap ◽  
Future Work

A new method to measure the frictional stresses and normal pressure in the roll gap during cold rolling, and experimental verification of this new method, are presented. The method overcomes many of the shortcomings of pin-type sensors. The elastic deformation of the roll itself is measured with strain gages, and is used to calculate the stresses between the sheet and the roll. Since no modification of the roll is necessary, the deformation process is undisturbed by the measurement. Mechanical isolation of the sensor is unnecessary. The mathematical procedure used to calculate the normal pressure and frictional stresses from the measured strains explicitly acknowledges that these strains are the result of the entire distribution of pressures and shears in the roll gap. An experimental rolling mill was constructed to verify the proposed method. Lead was rolled, and the resulting pressure and frictional stress distributions in the roll gap were measured. Several features of these distributions are in agreement with measurements made by various investigators using other techniques, thereby confirming the usefulness of the new method. Future work is proposed to increase the accuracy with which the roll gap stresses may be measured.

Simple Model for Contact Stress of Strands Bent over Circular Saddles

2016 ◽  
Author(s):  
Sherif Mohareb ◽  
Arndt Goldack ◽  
Mike Schlaich
Keyword(s):  
Simple Model ◽  
Stress Distribution ◽  
Contact Force ◽  
Contact Stress ◽  
Flexural Rigidity ◽  
Strong Nonlinearity ◽  
Stress Distributions ◽  
Maximum Contact ◽  
Contact Stress Distribution ◽  
Peak Value

Cable-stayed and extra-dosed bridges are today widely used bridge types. Recently, saddles have been used to deviate strands of cables in the pylons. Up to now the mechanics of strands on saddles are not well understood. It was found, that typical longitudinal contact stress distributions between strand and saddle show a strong nonlinearity and a high peak value around the detachment point, where the strand meets the saddle. This paper presents a procedure to analyse the longitudinal contact stress distribution obtained by FEM calculations: This contact stress can be idealised as a constant contact stress according to the Barlow's formula and a contact force at the detachment point due to the flexural rigidity of the bent tension elements. An analytical model is provided to verify this contact force. Finally, a formula is presented to calculate the maximum contact stress. This study provides the basis for further research on saddle design and fatigue of strands.

The Contact Problem for a Rigid Inclusion Pressed Between Two Dissimilar Elastic Half Planes

1981 ◽  
Vol 48 (1) ◽  
pp. 104-108
Author(s):  
G. M. L. Gladwell
Keyword(s):  
Contact Problem ◽  
Plane Strain ◽  
Integral Equations ◽  
Elastic Constants ◽  
Contact Stress ◽  
Rigid Inclusion ◽  
Numerical Results ◽  
Stress Distributions ◽  
Plane Strain Problem

Paper concerns the plane-strain problem of a rigid, thin, rounded inclusion pressed between two isotropic elastic half planes with different elastic constants. Required to find the extents of the contact regions between each plane and the inclusion, and the contact stress distributions. The governing integral equations are solved approximately by using Chebyshev expansions. Numerical results are presented.

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