scholarly journals The stress-strain state in the plate material, formed as a result of the movement of a heat source

2020 ◽  
pp. 194-201
Author(s):  
Евгений Евгеньевич Абашкин ◽  
Анастасия Валерьевна Ткачева
Keyword(s):  
Mathematical Model ◽  
Residual Stress ◽  
Yield Strength ◽  
Heat Source ◽  
Residual Stresses ◽  
Strain State ◽  
Stress Fields ◽  
Plate Material ◽  
Temperature Stresses ◽  
The Mathematical Model

Работа посвящена исследованию температурных напряжений в пластине из среднеуглеродистой легированной стали, по поверхности которой с определенной скоростью проходит прямолинейно источник тепла. Математическая модель строится на основе модели Прандтля - Рейса, в которой закон Гука заменен законом Дюамеля - Неймана. В качестве условия пластического течения принимается условие Мизесса, где предел текучести параболически зависит от температуры. Рассматриваются поля остаточных напряжений в зависимости от скорости прохождения источника тепла. Значения остаточных напряжений, полученные в результате расчета, сравниваются с экспериментальными напряжениями, снятыми с пластины при помощи анализатора остаточных напряжений RIGAKU. The work is devoted to the study of temperature stresses in a plate made of mediumcarbon alloy steel on the surface of which a heat source passes rectilinearly at a certain speed. The mathematical model is based on the Prandtl - Reis model, in which Hooke’s law is modified by the Duhamel - Neumann law. As a condition for plastic flow, the Mises condition is accepted, where the yield strength of the parabolic depends on the temperature. The residual stress fields are considered depending on the speed of the heat source passage. The resulting residual stresses are compared with the experimental stresses taken from the plate using the Rigaku residual stress analyzer.

scholarly journals Evaluation of the Carrying Capacity of Rectangular Steel-Concrete Columns

2018 ◽  
Vol 14 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Glib Vatulia ◽  
Maryna Rezunenko ◽  
Dmytro Petrenko ◽  
Sergii Rezunenko
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Yield Strength ◽  
Carrying Capacity ◽  
Strain State ◽  
Experimental Studies ◽  
Concrete Columns ◽  
Regression Parameters ◽  
The Mathematical Model ◽  
Crosssectional Area

AbstractExperimental studies of rectangular steel-concrete columns under centric compression with random eccentricity were conducted. The stress-strain state and the carrying capacity exhaustion have been assessed. The regression dependence is proposed to determine the maximum carrying capacity of such columns. The mathematical model takes into account the combined influence of the physical and geometric characteristics of the columns, such as their length, crosssectional area, casing thickness, prism strength of concrete, yield strength of steel, modulus of elasticity of both steel and concrete. The correspondence of the obtained model to the experimental data, as well as the significance of the regression parameters are confirmed by the Fisher and Student criteria.

Evaluation of the residual stress in stainless steel 304L hydraulically expanded joints

2020 ◽  
pp. 095440892096401
Author(s):  
Ying Hong ◽  
Xuesheng Wang ◽  
Yan Wang ◽  
Zhao Zhang ◽  
Yong Han
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Yield Strength ◽  
Residual Stresses ◽  
Heat Exchangers ◽  
Nuclear Power ◽  
The Finite Element Method ◽  
Power Stations ◽  
Stainless Steel 304 ◽  
Initial Clearance

Stainless steel 304 L tubes are commonly used in the fabrication of heat exchangers for nuclear power stations. The stress corrosion cracking (SCC) of 304 L tubes in hydraulically expanded tube-to-tubesheet joints is the main reason for the failure of heat exchangers. In this study, 304 L hydraulically expanded joint specimens were prepared and the residual stresses of a tube were evaluated with both an experimental method and the finite element method (FEM). The residual stresses in the outer and inner surfaces of the tube were measured by strain gauges. The expanding and unloading processes of the tube-to-tubesheet joints were simulated by the FEM. Furthermore, an SCC test was carried out to verify the results of the experimental measurement and the FEM. There was good agreement between the FEM and the experimental results. The distribution of the residual stress of the tube in the expanded joint was revealed by the FEM. The effects of the expansion pressure, initial tube-to-hole clearance, and yield strength of the tube on the residual stress in the transition zone that lay between the expanded and unexpanded region of the tube were investigated. The results showed that the residual stress of the expanded joint reached the maximum value when the initial clearance was eliminated. The residual stress level decreased with the decrease of the initial tube-to-hole clearance and yield strength. Finally, an effective method that would reduce the residual stress without losing tightness was proposed.

Mathematical Model Establishment and Analysis on the Pipe Deformation under External Pressure with the Ovality

2013 ◽  
Vol 760-762 ◽  
pp. 2263-2266
Author(s):  
Kang Yong ◽  
Wei Chen
Keyword(s):  
Mathematical Model ◽  
Theoretical Analysis ◽  
Yield Strength ◽  
Residual Stresses ◽  
Numerical Simulations ◽  
Significant Influence ◽  
External Pressure ◽  
Pipe Diameter ◽  
Axial Loads ◽  
The Stability

Beside the residual stresses and axial loads, other factors of pipe like ovality, moment could also bring a significant influence on pipe deformation under external pressure. The Standard of API-5C3 has discussed the influences of deformation caused by yield strength of pipe, pipe diameter and pipe thickness, but the factor of ovality degree is not included. Experiments and numerical simulations show that with the increasing of pipe ovality degree, the anti-deformation capability under external pressure will become lower, and ovality affecting the stability of pipe shape under external pressure is significant. So it could be a path to find out the mechanics relationship between ovality and pipe deformation under external pressure by the methods of numerical simulations and theoretical analysis.

Analysis of circumferentially welded thin-walled cylinders to study the effects of tack weld orientations and joint root opening on residual stress fields

2009 ◽  
Vol 223 (5) ◽  
pp. 1037-1049 ◽  
Author(s):  
N U Dar ◽  
E M Qureshi ◽  
A M Malik ◽  
M M I Hammouda ◽  
R A Azeem
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Arc Welding ◽  
Operating Conditions ◽  
Stress Fields ◽  
Welded Structures ◽  
Prime Concern ◽  
Thin Walled ◽  
Tack Weld ◽  
Welding Processes

In recent years, the demand for resilient welded structures with excellent in-service load-bearing capacity has been growing rapidly. The operating conditions (thermal and/or structural loads) are becoming more stringent, putting immense pressure on welding engineers to secure excellent quality welded structures. The local, non-uniform heating and subsequent cooling during the welding processes cause complex thermal stress—strain fields to develop, which finally leads to residual stresses, distortions, and their adverse consequences. Residual stresses are of prime concern to industries producing weld-integrated structures around the globe because of their obvious potential to cause dimensional instability in welded structures, and contribute to premature fracture/failure along with significant reduction in fatigue strength and in-service performance of welded structures. Arc welding with single or multiple weld runs is an appropriate and cost-effective joining method to produce high-strength structures in these industries. Multi-field interaction in arc welding makes it a complex manufacturing process. A number of geometric and process parameters contribute significant stress levels in arc-welded structures. In the present analysis, parametric studies have been conducted for the effects of a critical geometric parameter (i.e. tack weld) on the corresponding residual stress fields in circumferentially welded thin-walled cylinders. Tack weld offers considerable resistance to the shrinkage, and the orientation and size of tacks can altogether alter stress patterns within the weldments. Hence, a critical analysis for the effects of tack weld orientation is desirable.

Stress and Fatigue Life Modeling of Cannon Breech Closures Including Effects of Material Strength and Residual Stress

2000 ◽  
Vol 123 (1) ◽  
pp. 150-154
Author(s):  
John H. Underwood ◽  
Michael J. Glennon
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Fatigue Life ◽  
Yield Strength ◽  
Residual Stresses ◽  
Solid Mechanics ◽  
Element Model ◽  
Pressure Vessels ◽  
Material Strength ◽  
Element Analysis

Laboratory fatigue life results are summarized from several test series of high-strength steel cannon breech closure assemblies pressurized by rapid application of hydraulic oil. The tests were performed to determine safe fatigue lives of high-pressure components at the breech end of the cannon and breech assembly. Careful reanalysis of the fatigue life tests provides data for stress and fatigue life models for breech components, over the following ranges of key parameters: 380–745 MPa cyclic internal pressure; 100–160 mm bore diameter cannon pressure vessels; 1040–1170 MPa yield strength A723 steel; no residual stress, shot peen residual stress, overload residual stress. Modeling of applied and residual stresses at the location of the fatigue failure site is performed by elastic-plastic finite element analysis using ABAQUS and by solid mechanics analysis. Shot peen and overload residual stresses are modeled by superposing typical or calculated residual stress distributions on the applied stresses. Overload residual stresses are obtained directly from the finite element model of the breech, with the breech overload applied to the model in the same way as with actual components. Modeling of the fatigue life of the components is based on the fatigue intensity factor concept of Underwood and Parker, a fracture mechanics description of life that accounts for residual stresses, material yield strength and initial defect size. The fatigue life model describes six test conditions in a stress versus life plot with an R2 correlation of 0.94, and shows significantly lower correlation when known variations in yield strength, stress concentration factor, or residual stress are not included in the model input, thus demonstrating the model sensitivity to these variables.

scholarly journals Temperature and residual stress in the products, obtained by means of thermoforming

2019 ◽  
pp. 47-48
Author(s):  
M. A. Sheryshev
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Temperature Stresses

In the products obtained by thermoforming, the temperature stresses arising when fixing the shape of the product when the heated workpiece touches the forming tool are calculated. In addition, the residual stresses in the finished products are determined.

Relaxation of Residual Stresses in Bearing Rings Based on the Optimal Geometric Setup of Equipment for Centerless Running

2019 ◽  
Vol 973 ◽  
pp. 183-188
Author(s):  
Albert V. Korolev ◽  
Andrei F. Balayev ◽  
Boris M. Iznairov
Keyword(s):  
Mathematical Model ◽  
Residual Stress ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Elastic Strain ◽  
New Approach ◽  
Technological Method ◽  
Residual Stress Relaxation ◽  
Bearing Rings

This paper discusses the technological method of residual stress relaxation of bearing rings by centerless running with cylindrical rolls. Described a new approach to relieve residual stresses by centerless running of elastically-deforming rolls on the basis of the geometrical setup of the equipment. It was found that geometrical setup of the equipment influences an elastic strain of parts and the degree of residual stress relaxation. We obtained a mathematical model for calculation of setup parameters to ensure the required variation value of elastic strain of the part. The results of experiments confirm the influence of the geometric setup on the magnitude of residual stress relaxation.

The Study on Residual Stress Testing of Humidity Effect and Distribution Law for PMMA

2013 ◽  
Vol 631-632 ◽  
pp. 358-361
Author(s):  
Shang Wei ◽  
Yang Xiao Jing ◽  
Mao Cui ◽  
Guo Long
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Residual Stress ◽  
Stress Testing ◽  
Phase Shifting ◽  
Distribution Law ◽  
Humidity Effect ◽  
Boundary Stress ◽  
The Mathematical Model ◽  
Humidity Environment

Polymethyl methacrylate (PMMA) has shown some excellent performances. However the humidity environment affects mechanical properties of PMMA seriously. In this work, the digital phase-shifting photoelasticity is used to test the humidity stress of the boundary according to which we concluded that the boundary stress decreases gradually from the boundary to the inner. The mathematical model of the boundary stress distribution is established based on the distribution law of the boundary stress. This mathematical model can be used to predict the effect of the humidity environment to the boundary stress, and guide PMMA to use safely.

Residual Stress of Gear Meshing under Shakedown Condition with Direct Analysis

2012 ◽  
Vol 152-154 ◽  
pp. 877-882
Author(s):  
Yuan Yuan ◽  
Peng Fei Li ◽  
Kai Liu
Keyword(s):  
Mathematical Model ◽  
Residual Stress ◽  
Residual Stresses ◽  
Direct Method ◽  
Direct Analysis ◽  
Numerical Approach ◽  
Operating Life ◽  
Operator Split ◽  
Gear Contact ◽  
Residual Stresses And Strains

A shakedown mathematical model of gear contact has been developed. A direct method is applied to solve the mathematical model. Local coordinates are constructed on different meshing points because curvature of gear profile is not constant. Distributions of residual stresses and strains are given base on variable curvature surface. The numerical approach consists of an operator split technique, which transforms the elastic-plastic problem into a purely elastic problem and a residual problem with prescribed eigenstrains. The eigenstrains are determined using an incremental projection method. Contact stresses and contact residual stresses of meshing gear teeth with standard and modified profile are computed. The results show compressive residual stress can improve capacity of gear and operating life. This aspect may contribute to future developments in the understanding of gear durability.

Abrasive Waterjet Peening With Elastic Prestress: Subsurface Residual Stress Distribution

2007 ◽  
Author(s):  
Balaji Sadasivam ◽  
Alpay Hizal ◽  
Dwayne Arola
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Stress Field ◽  
Yield Strength ◽  
Residual Stresses ◽  
Residual Stress Distribution ◽  
Abrasive Waterjet ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Compressive Residual Stresses

Recent advances in abrasive waterjet (AWJ) technology have resulted in new processes for surface treatment that are capable of introducing compressive residual stresses with simultaneous changes in the surface texture. While the surface residual stress resulting from AWJ peening has been examined, the subsurface residual stress field resulting from this process has not been evaluated. In the present investigation, the subsurface residual stress distribution resulting from AWJ peening of Ti6Al4V and ASTM A228 steel were studied. Treatments were conducted with the targets subjected to an elastic prestress ranging from 0 to 75% of the substrate yield strength. The surface residual stress ranged from 680 to 1487 MPa for Ti6Al4V and 720 to 1554 MPa for ASTM A228 steel; the depth ranged from 265 to 370 μm for Ti6Al4V and 550 to 680 μm for ASTM A228 steel. Results showed that elastic prestress may be used to increase the surface residual stress in AWJ peened components by up to 100%.

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