A New Type of Precision Tire

1988 ◽  
Vol 16 (4) ◽  
pp. 200-207
Author(s):  
O. B. Tretyakov
Keyword(s):  
Stress Concentration ◽  
Failure Rates ◽  
Stress Strain ◽  
Radial Tire ◽  
Resonance Effects ◽  
Precision Stage ◽  
New Type ◽  
Degree Of Order

Abstract A process is suggested for improving the rubber-cord composite in a radial tire through precision stage-by-stage molding of its parts. This starts by casting an inner elastomeric envelope of the carcass from a liquid oligomer mix. The full molding technology uses acoustic and resonance effects to optimize the degree of order of the structure and of rubber uniformity. The resultant precision tires should have a higher degree of order of both macro- and microstructure than do present commercial tires. Reduced stress concentration in locations that have high failure rates in commercial tires are considered. A new theory, CSSOT, is used for optimizing tires from results of stress-strain cycles.

scholarly journals Stress strain state of elastic plate with elliptical cut-out

2020 ◽  
pp. 3-8
Author(s):  
E.E. Deryugin ◽  
Keyword(s):  
Plastic Deformation ◽  
Stress Concentration ◽  
Driving Force ◽  
Strain State ◽  
Mechanical State ◽  
Concentration Coefficient ◽  
Stress Strain ◽  
Crack Driving Force ◽  
Stress Strain State ◽  
Stress Concentration Coefficient

The article considers a crack in the form of a narrow cut with a certain cfn at the cut out in an unbounded plate. The characteristics of the mechanical state of this system under uniaxial loading are determined: the stress concentration coefficient, the crack-driving force, and the energy of a solid with a crack. The elastic energy expenditure during crack propagation is determined. The general regularities of the mechanical state of a solid with a crack, not necessary having the form of an ellipse, are revealed. An important parameter of a crack is the curvature at the tip. It is shown that the Griffiths crack does not actually have a singularity at the tip. The stress strain state of the plate with an elliptical crack is identical to the same of the plate with a focus of homogeneous plastic deformation.

Development and Implement of a New Shear Creep Apparatus

2011 ◽  
Vol 90-93 ◽  
pp. 1351-1354
Author(s):  
Xiao Yan Lin ◽  
Tong Lu Li
Keyword(s):  
Stress Concentration ◽  
Vertical Load ◽  
Shear Creep ◽  
Loading Process ◽  
Loading System ◽  
New Type ◽  
Shear Box ◽  
Margin Area

The conventional shear creep apparatus uses lever to amplify the load, which has a serious limitations in practical use. First, the round and small shearing box can easily form an obvious stress concentration in the margin area. In addition, tilting of the lever can give an unreal vertical load in loading process. Aiming to solve the shortages of conventional apparatus, a new type of shear creep apparatus is introduced in this paper, whose loading system apply the pulley block, and shear box is changed from the round with the area of 30cm2 into the present square one with 10×10cm2. The new shear creep apparatus has more advantage compared with the conventional, and is more satisfactory to the need of test.

Fracture Assessment of Pipes Having Multiple Flaws Based on Ramberg–Osgood-Type Stress–Strain Relationships

2011 ◽  
Author(s):  
Hideo Machida ◽  
Tetsuya Hamanaka ◽  
Yoshiaki Takahashi ◽  
Katsumasa Miyazaki ◽  
Fuminori Iwamatsu ◽  
...  
Keyword(s):  
Flow Stress ◽  
Stress Concentration ◽  
Fracture Strength ◽  
Strain Curve ◽  
Assessment Method ◽  
Experimental Results ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Strain Relationship ◽  
Fracture Assessment

This paper describes a fracture assessment method for a pipe having multiple circumferential flaws. According to Fitness-for-Service (FFS) codes for nuclear facilities published by the Japanese Society of Mechanical Engineers (JSME), the fracture strength of a high-ductility pipe having a circumferential flaw is evaluated using the limit load assessment method assuming the elastic–perfectly-plastic stress–strain relationship. In this assessment, flow stress is used as a proportional stress. However, previous experimental results [1, 2, 3] show that a crack penetrates before the entire flawed pipe section reaches the flow stress. Therefore, stress concentration at a flaw was evaluated on the basis of the Dugdale model [4], and the fracture strength of the crack-ligament was evaluated. This model can predict test results with high accuracy when the ligament fracture strength is assumed to be tensile strength. Based on this examination, a fracture assessment method for pipes having multiple flaws was developed considering the stress concentration in the crack-ligament by using the realistic stress–strain relationship (Ramberg–Osgood-type stress–strain curve). The fracture strength of a multiple-flawed pipe estimated by the developed method was compared with previous experimental results. When the stress concentration in the crack-ligament was taken into consideration, the fracture strength estimated using the Ramberg–Osgood-type stress–strain curve was in good agreement with experimental results, confirming the validity of the proposed method.

Structure and Lightweight Improvement of New Type of Mining Bucket

2013 ◽  
Vol 710 ◽  
pp. 281-284
Author(s):  
Ni Ni Hao ◽  
Yan Yu ◽  
Ji Hua Bao ◽  
Ling Wang ◽  
Ming Xia Gu
Keyword(s):  
Stress Concentration ◽  
Optimization Design ◽  
Peak Stress ◽  
Working Life ◽  
Dead Load ◽  
Improvement Measures ◽  
New Type

This paper takes the new type of mining truck bucket as research object and analyzes the strength and rigidity of the truck body in typical situations of dead load, swerve and slanting load. According to the analysis, the author will put forward four improvement measures in the stress concentration parts and give optimization design to those parts that have much allowance to the strength of the truck structure. The calculating result indicates that the improvement of the truck structure can significantly reduce the peak stress and improve the working life of the truck. In the premise of guaranteeing the strength of the truck structure, the weight of truck bucket induces from 30t to 27.1t achieves the goal of lightweight.

Experimental investigation on new low cycle fatigue precision cropping process

2014 ◽  
Vol 229 (8) ◽  
pp. 1470-1476 ◽  
Author(s):  
Renfeng Zhao ◽  
Shengdun Zhao ◽  
Bin Zhong ◽  
Yong Tang
Keyword(s):  
Stress Concentration ◽  
Cross Sections ◽  
Low Cycle Fatigue ◽  
Fatigue Loading ◽  
High Energy ◽  
Concentration Effect ◽  
Cycle Fatigue ◽  
Stable Crack Propagation ◽  
New Type ◽  
Stress Concentration Effect

The traditional cropping processes have some disadvantages, such as poor surface quality, low yield, the waste of materials, and high energy consumption. The low cycle fatigue precision cropping process with circumferential loading, which is a new type of precision cropping process, is studied. According to the stress concentration effect of the V-shape notch, the fatigue crack on the tip of the V-shape notch is prompted to initiate and extend. The working principle of the precision cropping machine is described. The criterion that whether the crack on the root of the V-shape notch is initiated or not is provided under the effect of low cycle fatigue loading. The materials which are 0.2%C steel, H59 copper, 0.45%C steel, 20Cr steel, and LY12 aluminum are tested under two control curves. The initiation and propagation of crack are accelerated and the good cross sections of the metal bar are obtained. The results show that the mean stress of the metal bar in the cropping process can be effectively reduced due to the stress concentration effect of the V-shape notch. The metal bar’s stable crack propagation and fracture can be obtained when constantly increasing striking displacement and reducing the striking frequency in the cropping process at the same time in the process.

Laboratory Evaluation of the Stress-Strain relationship of Permeable Concrete

2011 ◽  
Vol 243-249 ◽  
pp. 3259-3262 ◽  
Author(s):  
Manal Hussin ◽  
Zhu Ge Yan ◽  
Frank Bullen ◽  
Weena Lokuge
Keyword(s):  
Pore Space ◽  
Strain Curve ◽  
Laboratory Evaluation ◽  
Fine Aggregate ◽  
Stress Strain ◽  
Average Pore ◽  
Water To Cement Ratio ◽  
Strain Relationship ◽  
New Type ◽  
Relationship Of

The authors conducted research aimed at developing a new type of permeable concrete material with enhanced structural strength. This paper presents and discusses the results of their investigation on the unaxial compressive stress-strain relationship of porous concrete made with two different mix designs with constant water to cement ratio. The concrete mixes were designed with a target compressive strength between 15-25 MPa and target porosity between 10-15% to study the effect of pore sizes on the stress-strain curve. The average pore space was increased by increasing the relative amount of large aggregate. The reduction in the relative amount of fine aggregate increased the average pore space and resulted in a reduction in mix stiffness and a marginal increase in ultimate strength.

Thermal-Fatigue Analysis of Turbine Discs under Complex Thermo-Mechanical Loading with Account of Plasticity and Creep Effects

2015 ◽  
Vol 725-726 ◽  
pp. 955-960 ◽  
Author(s):  
Igor Ignatovich ◽  
Artem S. Semenov ◽  
Sergey Semenov ◽  
Leonid Getsov
Keyword(s):  
Stress Concentration ◽  
Strain State ◽  
Local Strain ◽  
Complex Stress ◽  
Material Behavior ◽  
Stress Concentration Zone ◽  
Concentration Zone ◽  
Stress Strain ◽  
Thermomechanical Cycling ◽  
Stress Strain State

During operation of transport and maneuverable gas-turbine units, there are crack formation in turbine disc rims what exerted by thermomechanical cycling loads. For in-depth study of these problems we have to use theories of plasticity and creep which form the basis for determining the complex stress-strain state in the stress concentration zone for disc rims, and a modern failure criterion which can predict lifetime under conditions of simultaneous plastic and creep strain accumulation. There is a finite-element method (FEM) that allows us to evaluate the stress-strain state in a stress concentration zone for a non-elastic material behavior. With plasticity and creep theories, it is possible to determine local strain quiet reliable by FEM.

scholarly journals Determination of the Actual Stress–Strain Diagram for Undermatching Welded Joint Using DIC and FEM

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4691
Author(s):  
Nenad Zoran Milošević ◽  
Aleksandar Stojan Sedmak ◽  
Gordana Miodrag Bakić ◽  
Vukić Lazić ◽  
Miloš Milošević ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Welded Joint ◽  
Rectangular Cross Section ◽  
Image Correlation ◽  
Strain Diagram ◽  
Numerical Verification ◽  
Martensitic Steels ◽  
Stress Strain ◽  
3D Digital Image Correlation ◽  
Actual Stress

This paper presents new methodology for determining the actual stress–strain diagram based on analytical equations, in combination with numerical and experimental data. The first step was to use the 3D digital image correlation (DIC) to estimate true stress–strain diagram by replacing common analytical expression for contraction with measured values. Next step was to estimate the stress concentration by using a new methodology, based on recently introduced analytical expressions and numerical verification by the finite element method (FEM), to obtain actual stress–strain diagrams, as named in this paper. The essence of new methodology is to introduce stress concentration factor into the procedure of actual stress evaluation. New methodology is then applied to determine actual stress–strain diagrams for two undermatched welded joints with different rectangular cross-section and groove shapes, made of martensitic steels X10 CrMoVNb 9-1 and Armox 500T. Results indicated that new methodology is a general one, since it is not dependent on welded joint material and geometry.

scholarly journals The research of the stress-strain state with local thinning in pipelines and determination of allowable values of concentration stress and strain

2019 ◽  
Vol 15 (5) ◽  
pp. 384-391
Author(s):  
Dmitry A. Kuzmin ◽  
Anastasia V. Andreenkova
Keyword(s):  
Stress Concentration ◽  
Internal Pressure ◽  
Wall Thickness ◽  
Strain State ◽  
Stress Strain ◽  
Flow Acceleration ◽  
Stress Strain State ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Equipment And Pipelines

Relevance. The nuclear power plant contains a large number of equipment and pipelines subject to flow acceleration corrosion. As a result of a combination of various parameters - sizes (diameters, wall thickness), operational parameters (internal pressure, temperature), steels and elements types - the number of design cases is tens of thousands, without counting the possible forms of thinning. The process of maintenance and repair at the stations are doing an assessment of the accordance of actual and allowable values of wall thicknesses. The ensuring safe operations of equipment and pipelines have been introduced correction functions for regulatory functions, taking into account the forms of thinning, to determine the permissible thinning. The aim of the work. The task is to determine the influence of the forms and types of thinning on the stress-strain state and to determine the most critical thinning for straight sections of pipelines subject to flow acceleration corrosion taking into account emergency conditions. Methods. The allowable values of stress concentration factors (deformations) of pipelines subject without flow acceleration corrosion was determined taking into account allowable values, the requirements of the federal norms and rules for emergency operating conditions. For researches of the stress concentration coefficients were used the finite element method and analytical methods for various shapes, sizes and depths of thinning. Results. A method has been developed, that allows getting the maximum allowable values of stress concentration factors (deformations) for emergency operation, which afford to determine the maximum allowable depth of thinning in emergency conditions - an above criterion. The researches have been carried out definition of the stress concentration factors for local thinning with various types of these thinning. The functions of concentration coefficients depending on the geometric parameters of local thinning wall thickness were determined for a straight section of the pipeline. As a result of the research, the dependences of the sizes of thinning on the concentration coefficients for straight pipelines were created and a master-curve was obtained. The researches were carried out take into account the load from internal pressure and bending moment.

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