Static analysis model of a non-pneumatic tire with elastic spokes contacting with rigid ground

Author(s):  
Chen Liang ◽  
Hao Liu ◽  
Hoda Mousavi ◽  
Kun Chen ◽  
Bentil Asafo-Duho ◽  
...  

An analytical model of a non-pneumatic tire is proposed to study the static deformation responses of a non-pneumatic tire in contact with a rigid ground. The tire consists of a shear band which is formed by an annular beam, and elastic spokes that connect the shear band to the rigid hub of the tire. The shear band is modeled using a Timoshenko beam. The spokes are modeled by linear springs, which are distributed evenly in circumferential direction. Governing equations of the model were derived using a theoretical analysis. The shear band static deformation was obtained based on the discussion of the relationship between spoke stiffness and the parameters of the shear band. A finite element model was developed to verify the accuracy of the model. As a part of the results from this study, a parametric analysis of quantities of interest for the tire is presented, which can be used in improving the optimal design of non-pneumatic tires. This scheme offers a holonomic solution for the complicated differential equations and gives a computationally efficient tool for rapid analyzing and designing such systems.

Author(s):  
Linfa Zhu ◽  
Zhimin Tan

The stress evaluation of tensile armor layer in bent unbonded flexible pipe due to end fitting termination is investigated. A preliminary mathematical stress analysis model which accounts for the boundary condition at the end fitting interface is developed. Two shifting parameters are introduced to correct the friction field acting on the tensile wires. Closed form solutions are obtained for the modified friction force, axial stress and displacement. The validity of this model is investigated through a comparison with results obtained using a 3D finite element model. The relationship between the shifting parameters and the initial hoop position of wires is discussed. Studies of local stress elevation on wires with different initial hoop positions are conducted. The results show that end fitting effect could causes a significant stress elevation in a large amount of tensile wires if heavy pipe bending is permitted at the end fitting vicinity.


Author(s):  
Yujin Han ◽  
He Li ◽  
Yunyu Xiao ◽  
Ang Li ◽  
Tingshao Zhu

(1) Purpose: The purpose of this study was to determine suicidal risk factors, the relationship and the underlying mechanism between social variables and suicidal behavior. We hope to provide empirical support for the future suicide prevention of social media users at the social level. (2) Methods: The path analysis model with psychache as the mediate variable was constructed to analyze the relationship between suicidal behavior and selected social macro variables. The data for our research was taken from the Chinese Suicide Dictionary, Moral Foundation Dictionary, Cultural Value Dictionary and National Bureau of Statistics. (3) Results: The path analysis model was an adequate representation of the data. With the mediator psychache, higher authority vice, individualism, and disposable income of residents significantly predicted less suicidal behavior. Purity vice, collectivism, and proportion of the primary industry had positive significant effect on suicidal behavior via the mediator psychache. The coefficients of harm vice, fairness vice, ingroup vice, public transport and car for every 10,000 people, urban population density, gross domestic product (GDP), urban registered unemployment rate, and crude divorce rate were not significant. Furthermore, we applied the model to three major economic development belts in China. The model’s result meant different economic zones had no influence on the model designed in our study. (4) Conclusions: Our evidence informs population-based suicide prevention policymakers that incorporating some social factors like authority vice, individualism, etc. can help prevent suicidal ideation in China.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmad H. Bokhari ◽  
Martin Berggren ◽  
Daniel Noreland ◽  
Eddie Wadbro

AbstractA subwoofer generates the lowest frequency range in loudspeaker systems. Subwoofers are used in audio systems for live concerts, movie theatres, home theatres, gaming consoles, cars, etc. During the last decades, numerical simulations have emerged as a cost- and time-efficient complement to traditional experiments in the design process of different products. The aim of this study is to reduce the computational time of simulating the average response for a given subwoofer design. To this end, we propose a hybrid 2D–3D model that reduces the computational time significantly compared to a full 3D model. The hybrid model describes the interaction between different subwoofer components as interacting modules whose acoustic properties can partly be pre-computed. This allows us to efficiently compute the performance of different subwoofer design layouts. The results of the hybrid model are validated against both a lumped element model and a full 3D model over a frequency band of interest. The hybrid model is found to be both accurate and computationally efficient.


2014 ◽  
Vol 989-994 ◽  
pp. 5540-5543
Author(s):  
Yong Chang Ren

China is in a critical period of urbanization, and various social contradictions continue to be accumulated, emerged and enlarged, so public crisis management mechanism has been highly valued by governments at all levels with the public crisis events are occurred frequently. The paper conducts study for the problems in the current urban public crisis handle mechanism. First, the evaluation model of crisis management can be researched, and crisis management can be divided into four stages to evaluate respectively, they are Reduction, Readiness, Response and Recovery; then, we should research crisis prediction model to strengthen prediction, prevention and monitoring of the crisis before the crisis happened; finally, stakeholders analysis model should be studied, and scientific analyzing the interests of the various stakeholders and the relationship among them. From the theoretical point of view, the paper carries on a study for crisis handle mechanism to provide support for improving the crisis handle level.


2014 ◽  
Vol 580-583 ◽  
pp. 3208-3214 ◽  
Author(s):  
Zhen Wei Xiong ◽  
Xin Ling Liang ◽  
Xian Xing Dai ◽  
Ping Wang

when the ballast track stretch with the bridge, ballast which is near expansion joint will move confusedly. As a result, rail produced vertical deformation. The deformation will affect the running safety and comfortability of train. At present, there are two kinds of treatments which are cover board structure and baffle structure to deal ballast’s movement. Aiming at the different modes of stretching when the two kinds of structures and different arrangement condition of bridge plate are applied, the rail-sleeper-ballast discrete element model is developed by the method of two-dimensional granular flow. The relationship between rail deformation and bridge expansion is analyzed on the foundation of the model. Results show as flows: when bridge extends or shortens, rail always produced upwarp deformation. Bridge plate should arrange asymmetrically. Like this, the rail deformation decrease by 40%. And adopting the baffle structure can effectively reduce the influence of bridge expansion in ballast truck.


Author(s):  
V. Ramirez-Elias ◽  
E. Ledesma-Orozco ◽  
H. Hernandez-Moreno

This paper shows the finite element simulation of a representative specimen from the firewall section in the AEROMARMI ESTELA M1 aircraft. This specimen is manufactured in glass and carbon / epoxy laminates. The specimen is subjected to a load which direction and magnitude are determined by a previous dynamic loads study [10], taking into account the maximum load factor allowed by the FAA (Federal Aviation Administration) for utilitarian aircrafts [11]. A representative specimen is manufactured with the same features of the firewall. Meanwhile a fix is built in order to introduce the load directions on the representative specimen. The relationship between load and displacement is plotted for this representative specimen, whence the maximum displacement at the specific load is obtained, afterwards it is compared with the finite element model, which is modified in its laminate thicknesses in order to decrease the deviation error; subsequently this features could be applied to perform the whole firewall analysis in a future model [10].


1999 ◽  
Author(s):  
Hwan-Sik Yoon ◽  
Gregory Washington

Abstract In this study, a smart aperture antenna of spherical shape is modeled and experimentally verified. The antenna is modeled as a shallow spherical shell with a small hole at the apex for mounting. Starting from five governing equations of the shallow spherical shell, two governing equations are derived in terms of a stress function and the axial deflection using Reissner’s approach. As actuators, four PZT strip actuators are attached along the meridians separated by 90 degrees respectively. The forces developed by the actuators are considered as distributed pressure loads on the shell surface instead of being applied as boundary conditions like previous studies. This new way of applying the actuation force necessitates solving for the particular solutions in addition to the homogeneous solutions for the governing equations. The amount of deflections is evaluated from the calculated stress function and the axial deflection. In addition to the analytical model, a finite element model is developed to verify the analytical model on the various surface positions of the reflector. Finally, an actual working model of the reflector is built and tested in a zero gravity environment, and the results of the theoretical model are verified by comparing them to the experimental data.


1985 ◽  
Vol 107 (1) ◽  
pp. 141-146
Author(s):  
G. Umasankar ◽  
C. R. Mischke

A simple method of computing the effect of a dimensional change at a particular element of a stepped shaft on two bearings, on bending deflections, and on slopes of the neutral axis at any of the nodes of interest is presented. The changes in deflection and slope of the neutral axis are derived as incremental quantities and as functions of the dimension change and the prior deflections and slopes of the neutral axis of the shaft. For shaft synthesis, the implications are that one can begin with a uniform diameter bar subjected to the loading and make a complete deflection analysis with superposed closed-form relations. Then the geometry can be modified element by element and the deflectional changes easily updated. This is computationally efficient. Further, deflections and deflection changes computed using the proposed method are identical to those obtained using a finite beam element model of the shaft.


2019 ◽  
Vol 18 (3) ◽  
pp. 89-99
Author(s):  
Vinh Huy Chau ◽  
Anh Thu Vo ◽  
Ba Tuan Le

Abstract As a up and coming sport, powerlifting is gathering more and more attetion. Powerlifters vary in their strength levels and performances at different ages as well as differing in height and weight. Hence the questions arises on how to establish the relationship between age and weight. It is difficult to judge the performance of athletes by artificial expertise, as subjective factors affecting the performance of powerlifters often fail to achieve the desired results. In recent years, artificial intelligence has made groundbreaking strides. Therefore, using artificial intelligence to predict the performance of athletes is among one of many interesting topics in sports competitions. Based on the artificial intelligence algorithm, this research proposes an analysis model of powerlifters’ performance. The results show that the method proposed in this paper can predict the best performance of powerlifters. Coefficient of determination-R2=0.86 and root-mean-square error of prediction-RMSEP=20.98 demonstrate the effectiveness of our method.


Author(s):  
N. Lomov ◽  
S. Sidyakin

The concept of morphological moments of binary images is introduced. Morphological moments can be used as a shape descriptor combining an integral width description of an object with a description of its spatial distribution. The relationship between the proposed descriptor and the disc cover of the figure is discussed and an exact analytical method for descriptor calculation is proposed within the continuous morphology framework. The approach is based on the approximation of the shape by a polygonal figure and the extraction of its medial representation in the form of the continuous skeleton and the radial function. The proposed method for calculation of morphological moments achieves high accuracy and it is computationally efficient. Experimentations have been conducted. Obtained results indicate that the morphological moments are a more informative and rich shape descriptor than the area of the disc cover. Application of morphological moments to the font recognition task improves the recognition quality.


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