scholarly journals Measuring the Normal Stress Distribution Acting on a Locked-Wheel of Push–Pull Locomotion Rovers via a Wheel Sensor System

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4434
Author(s):  
Daisuke Fujiwara ◽  
Tetsuya Oshima ◽  
Kojiro Iizuka
Keyword(s):  
Stress Distribution ◽  
Normal Stress ◽  
Contact Area ◽  
Slip Surface ◽  
Tangential Force ◽  
Measured Data ◽  
Sensor System ◽  
Resistance Force ◽  
Normal Stress Distribution ◽  
Wheel Sensor

The resistance force generated when the locked-wheel acts on the soil is critical for deciding the traveling performance of push–pull locomotion. The resistance force depends on the tangential force of the sliding soil wedge beneath the wheel, and the tangential force depends on the forces of the soil and the wheel perpendicular to the tangential direction. Hence, the normal stress distribution of the locked-wheel can affect the resistance force. Previous studies indicated different insights that describe either a uniform or non-uniform shape of the normal stress distribution. The distribution of the locked-wheel still needs to be examined experimentally. This study measured the normal stress distribution using the wheel sensor system, and the variation of the contact area and slip surface beneath the wheel were also observed in PIV analysis. Those results showed that the normal stress distribution was non-uniform along the wheel contact area, and the change of the distribution was confirmed with the change of the contact area and slip surface. Then, the resistance force calculated by a preliminary model based on the measured data was compared with the total resistance force of the wheel measured by a separate sensor. This comparison provided a theoretical consideration for the measured data.

scholarly journals Evaluation of the stability of anchor-reinforced slopes

2005 ◽  
Vol 42 (5) ◽  
pp. 1342-1349 ◽  
Author(s):  
D Y Zhu ◽  
C F Lee ◽  
D H Chan ◽  
H D Jiang
Keyword(s):  
Stress Distribution ◽  
Normal Stress ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Load Factor ◽  
Normal Stress Distribution ◽  
Abrupt Changes ◽  
Reinforced Slopes ◽  
The Stability

The conventional methods of slices are commonly used for the analysis of slope stability. When anchor loads are involved, they are often treated as point loads, which may lead to abrupt changes in the normal stress distribution on the potential slip surface. As such abrupt changes are not reasonable and do not reflect reality in the field, an alternative approach based on the limit equilibrium principle is proposed for the evaluation of the stability of anchor-reinforced slopes. With this approach, the normal stress distribution over the slip surface before the application of the anchor (i.e., σ0) is computed by the conventional, rigorous methods of slices, and the normal stress on the slip surface purely induced by the anchor load (i.e., λpσp, where λp is the load factor) is taken as the analytical elastic stress distribution in an infinite wedge approximating the slope geometry, with the anchor load acting on the apex. Then the normal stress on the slip surface for the anchor-reinforced slope is assumed to be the linear combination of these two normal stresses involving two auxiliary unknowns, η1 and η2; that is, σ = η1σ0 + η2λpσp. Simultaneously solving the horizontal force, the vertical force, and the moment equilibrium equations for the sliding body leads to the explicit expression for the factor of safety (Fs)—or the load factor (λp), if the required factor of safety is prescribed. The reasonableness and advantages of the present method in comparison with the conventional procedures are demonstrated with two illustrative examples. The proposed procedure can be readily applied to designs of excavated slopes or remediation of landslides with steel anchors or prestressed cables, as well as with soil nails or geotextile reinforcements.Key words: slopes, factor of safety, anchors, limit equilibrium method.

scholarly journals The Influence of Initial Normal Stress Assumption of Slip Surface on Safety Factor of Symmetrical Three-Dimensional Slopes

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Huali Liu
Keyword(s):  
Stress Distribution ◽  
Normal Stress ◽  
Safety Factor ◽  
Slip Surface ◽  
Three Dimensional ◽  
Normal Stresses ◽  
Equilibrium Conditions ◽  
Normal Stress Distribution ◽  
A Value ◽  
Force Equilibrium

By using the explicit solution of three-dimensional slope stability based on modification of normal stress distribution over the slip surface, the influence of assumption of the three-dimensional initial normal stress on the safety factor is investigated. The initial normal stress distribution over the 3D slip surface was assumed, and then it was modified by a function with 2 parameters to satisfy two force equilibrium conditions about two axes and one moment equilibrium condition around one axis. An iterative equation was derived that would yield a value to 3D safety factor. The values of three-dimensional safety factor of symmetrical slopes are computed with different assumptions of initial normal stresses. The computation results show that the influence of assumption of initial normal stress on the safety factor of symmetrical three-dimensional slopes is negligible because the maximum different value of the three-dimensional safety factor is below 5%.

Stress in Bonded Adherends for Single Lap Joints

1996 ◽  
Vol 12 (03) ◽  
pp. 167-171
Author(s):  
G. Bezine ◽  
A. Roy ◽  
A. Vinet
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Numerical Model ◽  
Stress Distribution ◽  
Normal Stress ◽  
Lap Joints ◽  
Axial Loads ◽  
Normal Stress Distribution ◽  
Single Lap Joints ◽  
Element Technique

A finite-element technique is used to predict the shear stress and normal stress distribution in adherends for polycarbonate/polycarbonate single lap joints subjected to axial loads. Numerical and photoelastic results are compared so that a validation of the numerical model is obtained. The influences on stresses of the overlap length and the shape of the adherends are studied.

Normal stress distribution adjacent to optimum holes in composite plates

1994 ◽  
Vol 29 (4) ◽  
pp. 393-398 ◽  
Author(s):  
R. Ramesh Kumar ◽  
G. Venkateswara Rao ◽  
K.S. Suresh
Keyword(s):  
Stress Distribution ◽  
Normal Stress ◽  
Composite Plates ◽  
Normal Stress Distribution

Stresses in a Thick Plate With Axially Symmetric Loading

1965 ◽  
Vol 32 (2) ◽  
pp. 458-459 ◽  
Author(s):  
T. J. Lardner
Keyword(s):  
Stress Distribution ◽  
Normal Stress ◽  
Numerical Integration ◽  
Elastic Plate ◽  
Thick Plate ◽  
Axially Symmetric ◽  
Pressure Loading ◽  
Normal Stress Distribution ◽  
Symmetric Loading

The problem of the thick elastic plate with a symmetric circular pressure loading is considered. The normal stress distribution on the midplane and for two positions off the midplane is obtained by a numerical integration of the solutions. A comparison of the stress distribution on the midplane is made with previous results.

Normal stress distribution in highly concentrated suspensions undergoing squeeze flow

2013 ◽  
Vol 52 (2) ◽  
pp. 155-163 ◽  
Author(s):  
Mohsen Nikkhoo ◽  
Khosrow Khodabandehlou ◽  
LeAnne Brozovsky ◽  
Francis Gadala-Maria
Keyword(s):  
Stress Distribution ◽  
Normal Stress ◽  
Squeeze Flow ◽  
Concentrated Suspensions ◽  
Normal Stress Distribution

The Research of Pure Bending Flanged Beam’s Stress Distribution in Civil Engineering

2012 ◽  
Vol 568 ◽  
pp. 168-171
Author(s):  
Jian Ou Pan ◽  
Yu Jing Jia ◽  
Guang Zhen Cheng
Keyword(s):  
Stress Distribution ◽  
Normal Stress ◽  
Civil Engineering ◽  
Effective Means ◽  
Measurement Technology ◽  
Stress And Strain ◽  
Test Bed ◽  
Pure Bending ◽  
Normal Stress Distribution ◽  
Measuring Point

Experimental method is an important means to research the mechanical properties of materials in civil engineering. In this paper, first, analyzing the section of pure bending beam’s normal-stress distribution, drafting the measure scheme of flanged beam’s pure bending normal-stress, arranging measuring point in different place about the section of pure bending, adopting multi-function composite test-bed, static strain gauge and other testing instrument, by step loading, to finish the measure of each measuring points’ stress and strain, also, analysis and treatment for test data. According to the result of analysis and treatment, pointing out that measured stress and strain of pure bending beam is proportional to loading. The measured normal-stress distribution of the pure bend beam is uniform with theoretical analysis, which is satisfy the engineering demand. Knowing and mastering multipoint measurement technology and method is an effective means for the scientific research.

Observations by Evaluating the Uncertainty of Stress Distribution in Truss Structures Based on Probabilistic and Possibilistic Methods

2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Sushan Li ◽  
Roland Platz
Keyword(s):  
Monte Carlo ◽  
Stress Distribution ◽  
Normal Stress ◽  
Direct Methods ◽  
Truss Structure ◽  
Truss Structures ◽  
Model Parameters ◽  
Normal Stress Distribution ◽  
Fuzzy Analysis ◽  
Input Parameters

Load-bearing mechanical structures like trusses face uncertainty in loading along with uncertainty in stress and strength, which are due to uncertainty in their development, production, and usage. According to the working hypothesis of the German Collaborative Research Center SFB 805, uncertainty occurs in processes that are not or only partial deterministic and can only be controlled in processes. The authors classify, compare, and evaluate four different direct methods to describe and evaluate the uncertainty of normal stress distribution in simple truss structures with one column, two columns, and three columns. The four methods are the direct Monte Carlo (DMC) simulation, the direct quasi-Monte Carlo (DQMC) simulation, the direct interval, and the direct fuzzy analysis with α-cuts, which are common methods for data uncertainty analysis. The DMC simulation and the DQMC simulation are categorized as probabilistic methods to evaluate the stochastic uncertainty. On the contrary, the direct interval and the direct fuzzy analysis with α-cuts are categorized as possibilistic methods to evaluate the nonstochastic uncertainty. Three different truss structures with increasing model complexity, a single-column, a two-column, and a three-column systems are chosen as reference systems in this study. Each truss structure is excited with a vertical external point load. The input parameters of the truss structures are the internal system properties such as geometry and material parameters, and the external properties such as magnitude and direction of load. The probabilistic and the possibilistic methods are applied to each truss structure to describe and evaluate its uncertainty in the developing phase. The DMC simulation and DQMC simulation are carried out with full or “direct” sample sets of model parameters such as geometry parameters and state parameters such as forces, and a sensitivity analysis is conducted to identify the influence of every model and state input parameter on the normal stress, which is the output variable of the truss structures. In parallel, the direct interval and the direct fuzzy analysis with α-cuts are carried out without altering and, therefore, they are direct approaches as well. The four direct methods are then compared based on the simulation results. The criteria of the comparison are the uncertainty in the deviation of the normal stress in one column of each truss structure due to varied model and state input parameters, the computational costs, as well as the implementation complexity of the applied methods.

scholarly journals Solution of the Boussinesq’s problem in evaluating ratio between shear stress and contact pressure

2020 ◽  
pp. 139-151
Author(s):  
Е.Г. Хитров ◽  
А.В. Андронов ◽  
Е.В. Нестерова
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Normal Stress ◽  
Contact Pressure ◽  
Stress Function ◽  
Average Pressure ◽  
Normal Stress Distribution ◽  
Contact Patch ◽  
Wide Range ◽  
Boussinesq’S Problem

Решение фундаментальной задачи Буссинеска широко используется в технических науках и позволяет эффективно решать широкий спектр задач науки о лесозаготовительном производстве. На его основе удается получить практически значимые результаты в области оценки распределения напряжений, возникающих в обрабатываемом материале под воздействием рабочего органа. Цель нашего исследования - проанализировать результаты расчетов и установить соотношение максимального значения касательного напряжения и среднего значения давления по пятну контакта рабочего органа с обрабатываемом материалом. Теоретическую основу работы составляют уравнения распределения нормальных и касательных напряжений, возникающих в упругом полупространстве при вдавливании в него жесткого клина. В результате анализа теоретических расчетов показано, что характер затухания нормального напряжения по глубине деформируемого массива материала с высокой точностью аппроксимируется квадратичной функцией (на основе полученной приближенной функции выполнено сопоставление среднего давления по пятну контакта индентора с массивом и нормального напряжения по глубине массива). При этом, как показали результаты расчетов, функция распространения касательного напряжения в деформируемом массиве имеет экстремум. Выполнено сопоставление полученных данных по значению экстремума функции касательного напряжения со значением приближенной функции нормального напряжения на границе контакта индентора сдеформируемым массивом. В результате показано, что максимальное по модулю касательное напряжение составляет 11-12% среднего контактного давления. Расчеты проведены при варьировании коэффициента Пуассона материала массива, установленное соотношение остается практически неизменным. Solution of fundamental Boussinesq’s problem is widely used in technical sciences and allows effectively solving a wide range of problems in forestry science. On its basis, it is possible to obtain practically significant results in the field of assessing the distribution of stresses arising in processed material under the influence of a working body. The purpose of our study is to analyze the results of calculations and establish the ratio of the maximum value of the shear stress and the average pressure over the contact patch of the working body with the material being processed. The theoretical basis of the work is formed by the equations for the distribution of normal and tangential stresses arising in an elastic half-space when a rigid cone is pressed into it. As a result of the analysis of the results of theoretical calculations, it was shown that the character of the normal stress distribution over the depth of the deformed massif of material is approximated with high accuracy by a quadratic function (based on the obtained approximate function, the average pressure over the contact patch of the indenter with the massif and the normal stress over the depth of the massif were compared). In this case, as shown by the results of calculations, the function of the shear stress distribution in the deformed massif has the extremum. Comparison of the obtained data on the value of the extremum of the shear stress function with the value of the approximate normal stress function at the interface of the indenter contact with the deformable mass is performed. As a result, it is shown that the maximum shear stress in absolute value is 11-12% of the average contact pressure. The calculations were carried out with varying Poisson's ratio of the massif material; the established ratio remains practically unchanged.

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