Macroscopic Dynamical Fluctuations in Kac Ring Model

Abstract A rigid ring model of the tire for the study of in-plane dynamics and a new technique for determining the parameters of the model are presented in this paper. This model can be used for studying the comfort of vehicles, problems of driving, and braking problems in the longitudinal direction. Comparison with finite element models shows that the rigid ring model of the tire is capable of describing the in-plane eigenmode shapes in the frequency range of 0–130 Hz. The well-known “brush model,” integrated into the tire model, is introduced to take into account the slide phenomena in the contact patch. The parameters of the model can be correlated with the physical properties of the tire so that designers can take advantage of such a correlation in the development of new tires in terms of time, cost, and performance. The technique used to determine the parameters of the model for some automobile tires include the direct measurements of some physical properties (mass, moment of inertia, stiffness) and a method of identification applied on the results from a dynamic test. The model is able to predict experimental data in terms of natural frequencies and relative dampings. Results from the application of this technique on two tires are reported.

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Tire Rolling Kinematics Model for an Intelligent Tire Based on an Accelerometer

Tire Science and Technology ◽

10.2346/tire.20.190211 ◽

2020 ◽

Vol 48 (4) ◽

pp. 287-314

Author(s):

Yan Wang ◽

Zhe Liu ◽

Michael Kaliske ◽

Yintao Wei

Keyword(s):

Elastic Deformation ◽

Estimation Algorithm ◽

Force Sensor ◽

Euler Method ◽

Rolling Contact ◽

Body Motion ◽

Identification Algorithm ◽

Active Perception ◽

Kinematics Model ◽

Ring Model

ABSTRACT The idea of intelligent tires is to develop a tire into an active perception component or a force sensor with an embedded microsensor, such as an accelerometer. A tire rolling kinematics model is necessary to link the acceleration measured with the tire body elastic deformation, based on which the tire forces can be identified. Although intelligent tires have attracted wide interest in recent years, a theoretical model for the rolling kinematics of acceleration fields is still lacking. Therefore, this paper focuses on an explicit formulation for the tire rolling kinematics of acceleration, thereby providing a foundation for the force identification algorithms for an accelerometer-based intelligent tire. The Lagrange–Euler method is used to describe the acceleration field and contact deformation of rolling contact structures. Then, the three-axis acceleration vectors can be expressed by coupling rigid body motion and elastic deformation. To obtain an analytical expression of the full tire deformation, a three-dimensional tire ring model is solved with the tire–road deformation as boundary conditions. After parameterizing the ring model for a radial tire, the developed method is applied and validated by comparing the calculated three-axis accelerations with those measured by the accelerometer. Based on the features of acceleration, especially the distinct peak values corresponding to the tire leading and trailing edges, an intelligent tire identification algorithm is established to predict the tire–road contact length and tire vertical load. A simulation and experiments are conducted to verify the accuracy of the estimation algorithm, the results of which demonstrate good agreement. The proposed model provides a solid theoretical foundation for an acceleration-based intelligent tire.

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Analysis of the Contact Deformation of a Radial Tire with Camber Angle

Tire Science and Technology ◽

10.2346/1.2137494 ◽

1995 ◽

Vol 23 (1) ◽

pp. 26-51 ◽

Cited By ~ 5

Author(s):

S. Kagami ◽

T. Akasaka ◽

H. Shiobara ◽

A. Hasegawa

Keyword(s):

Pressure Distribution ◽

Contact Pressure ◽

Contact Region ◽

Contact Deformation ◽

Contact Pressure Distribution ◽

Radial Tire ◽

Ring Model ◽

Camber Angle ◽

Contact Free ◽

Good Agreement

Abstract The contact deformation of a radial tire with a camber angle, has been an important problem closely related to the cornering characteristics of radial tires. The analysis of this problem has been considered to be so difficult mathematically in describing the asymmetric deformation of a radial tire contacting with the roadway, that few papers have been published. In this paper, we present an analytical approach to this problem by using a spring bedded ring model consisting of sidewall spring systems in the radial, the lateral, and the circumferential directions and a spring bed of the tread rubber, together with a ring strip of the composite belt. Analytical solutions for each belt deformation in the contact and the contact-free regions are connected by appropriate boundary conditions at both ends. Galerkin's method is used for solving the additional deflection function defined in the contact region. This function plays an important role in determining the contact pressure distribution. Numerical calculations and experiments are conducted for a radial tire of 175SR14. Good agreement between the predicted and the measured results was obtained for two dimensional contact pressure distribution and the camber thrust characterized by the camber angle.

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Rat Aortic Ring Model to Assay Angiogenesis ex vivo

BIO-PROTOCOL ◽

10.21769/bioprotoc.1622 ◽

2015 ◽

Vol 5 (20) ◽

Author(s):

Isabelle Ernens ◽

B�n�dicte Lenoir ◽

Yvan Devaux ◽

Daniel Wagner

Keyword(s):

Ex Vivo ◽

Aortic Ring ◽

Ring Model ◽

Rat Aortic Ring Model

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Development of the mouse anterior amygdalar radial unit marked by Lhx9-expression

Brain Structure and Function ◽

10.1007/s00429-020-02201-8 ◽

2021 ◽

Vol 226 (2) ◽

pp. 575-600 ◽

Cited By ~ 1

Author(s):

Elena Garcia-Calero ◽

Luis Puelles

Keyword(s):

Emotional Processing ◽

Molecular Profile ◽

Ring Model ◽

Radial Model ◽

Developmental Features ◽

Anterior Posterior

AbstractThe amygdala in mammals plays a key role in emotional processing and learning, being subdivided in pallial and subpallial derivatives. Recently, the cortical ring model and the pallial amygdalar radial model (Puelles et al. 2019; Garcia-Calero et al. 2020) described the pallial amygdala as an histogenetic field external to the allocortical ring, and subdivided it in five major radial domains called lateral, basal, anterior, posterior and retroendopiriform units. The anterior radial unit, whose cells typically express the Lhx9 gene (see molecular profile in Garcia-Calero et al. 2020), is located next to the pallial/subpallial boundary. This radial domain shows massive radial translocation and accumulation of its derivatives into its intermediate and superficial strata, with only a glial palisade representing its final periventricular domain. To better understand the development of this singular radial domain, not described previously, we followed the expression of Lhx9 during mouse amygdalar development in the context of the postulated radial subdivisions of the pallial amygdala and other telencephalic developmental features.

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3D PRINTING PREOPERATIVE PLANNING AND CUSTOMIZED SURGICAL GUIDES ASSOCIATED WITH O-ARM NAVIGATION SYSTEM FOR MULTIPLANAR OSTEOTOMY OF COMPLEX PELVIC DEFORMITY

British Journal of Surgery ◽

10.1093/bjs/znab160.025 ◽

2021 ◽

Vol 108 (Supplement_3) ◽

Author(s):

M Fernández Álvarez ◽

C Garcés Zarzalejo ◽

M Adeba García ◽

P Pernia Gomez ◽

J A. Martínez Agüeros ◽

...

Keyword(s):

3D Printing ◽

Navigation System ◽

Pelvic Ring ◽

Posterior Column ◽

Pubic Ramus ◽

Printing Technology ◽

3D Printing Technology ◽

Ring Model ◽

Surgical Guides ◽

Hip Rotation

Abstract INTRODUCTION 3D printing technology is penetrating the healthcare field at an astonishing rate. The reduction of its costs, makes it more accessible to everyone. MATERIAL AND METHODS 35-year-old woman who had functional limitation in her right hip due to pelvic ring fracture in her childhood. She had dysmetria of lower limbs and femoral anteversion of 40 degrees. Imaging tests showed vicious consolidation of the right hemipelvis associated with antero-medial displacement. RESULTS Preoperative, we performed her 3D printing pelvic ring model. Osteotomies were digital planned (iliac crest, superior pubic ramus, incomplete of inferior pubic ramus, and semicircular of posterior column) and also how many degrees we would need for rotation the osteotomized fragment. Posterior column osteotomy was the most difficult, so we designed 3D surgical printing cutting guide able to being inserted into the iliac fossa. We used it to introduced four Kirschnner wires that leads us as a guide to avoid the greater sciatic notch. O-arm navigation system helped us make sure to achieve more precision. 3D printing pelvic ring model was sterilized to pre-contouring osteosynthesis plates. After two years of follow-up, good functional results were observed, without gait claudication either limb dysmetria. Her range of motion is 105 degrees of hip flexion, 20 degrees of internal hip rotation and 40 degrees of external hip rotation. Complete radiological consolidation was observed. CONCLUSION Digital planning and 3D printing technology allows to improve three-dimensional compression of bone pathology leading to a higher likelihood of a predictable ideal outcome compared to conventional techniques.

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