scholarly journals Simulation-Based Methodology for Determining the Dynamic Strength of Tire Inflation Restraining Devices

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 991 ◽  
Author(s):  
Jacek Karliński ◽  
Mariusz Ptak ◽  
Leszek Chybowski
Keyword(s):  
Permanent Deformation ◽  
Equivalent Stress ◽  
Dynamic Strength ◽  
Strength Criteria ◽  
Contour Lines ◽  
Simulation Based ◽  
Strength Tests ◽  
Principal Tool ◽  
Plastic Displacement ◽  
Operator Safety

The article suggests and supports a simulation-based methodology for determining whether the dynamic strength of tire inflation restraining devices for tire inflation meet quality requirements and ensure operator safety during a potential tire explosion. Dynamic strength tests using an NM-600 safety shield and NK-0728 safety cage during a 29.5 R25X tire explosion at a pressure of 10 bar were presented as an example application of this methodology. The shield was subjected to destructive tests involving the use of a 2200 kg impactor, dropping it so that the minimum kinetic energy reached 20 kJ at the time of impact. Analyzed devices were constructed of S355 steel in accordance with EN 10025. The Cowper–Symonds model of material for strain rate phenomena was used in the calculations. Simulations of a 20 kJ ring impact against the cage were performed. The equivalent stress distribution was determined, and displacement contour lines for the maximum dynamic deformation value and plastic deformation were calculated. The plastic displacement obtained in numerical tests was equal to the permanent deformation recorded in the experimental test. Further, the simulations showed that the examined cage met the assumed strength criteria. The conducted tests confirmed the usefulness of the proposed methodology for assessing the dynamic strength of safety cages and shields for tire inflation. The full-scale, physical cage testing is difficult to implement because it requires placing a ring impacting the cage wall. This is a major boundary for closed cages, as considered in this publication. Thus, simulation-based methods are becoming a principal tool for safety assessment of tire inflation restraining devices.

scholarly journals Using the Mathematical Criterion of Gas Pipeline Failure to Determine the Remaining Operation Life

2021 ◽  
Vol 248 ◽  
pp. 04021
Author(s):  
Minsariya Bayburova ◽  
Zulfiya Ismagilova
Keyword(s):  
Tensile Strength ◽  
Cyclic Loading ◽  
Main Pipeline ◽  
Strength Criteria ◽  
Loading Method ◽  
Underground Pipelines ◽  
Strength Tests ◽  
Pipeline Failure ◽  
Pipeline Route ◽  
Wear Damage

During the years of operation, underground pipelines deteriorate because of aging, wear, damage, and destruction. A comprehensive inspection of the main pipeline revealed various defects on a certain pipeline route section. To identify the remaining operation life of the pipeline, a number of hydraulic tensile strength tests were performed using the cyclic loading method. The authors propose to calculate the minimum allowable wall thickness capable of withstanding the maximum internal pressure, as an alternative to cyclic hydraulic tests. The strength calculations were performed using the well-known mathematical strength criteria proposed by K.V. Zakharov and I.I. Goldenblatt and V.A. Kopnov.

Finite-Element Simulation of Steckel Mill Rolling

2021 ◽  
Vol 887 ◽  
pp. 564-574
Author(s):  
Oleksandr H. Kurpe ◽  
Volodymyr V. Kukhar ◽  
Eduard S. Klimov
Keyword(s):  
Analytical Modeling ◽  
Rolling Force ◽  
Equivalent Stress ◽  
Rolling Process ◽  
Layer Formation ◽  
Average Value ◽  
Hot Rolling Process ◽  
Element Simulation ◽  
Simulation Based ◽  
Entire Thickness

In the paper the research has been performed to obtain the stress distribution through the thickness of the rolled products along the deformation zone in the conditions of roughing rolling and in the conditions of quasi-stationary temperature distribution during finishing rolling at the Steckel mill. The research has been performed by the simulation based on the Abaqus CAE 6.14-2 software and analytical modeling of the hot rolling process of coils at the Steckel mill with dimensions of 15 mm × 1500 mm, made of steel grade S355JR+AR, according to the requirements of EN 10025-2. The obtained deviations of the rolling force between simulation, analytical modeling and actual data have comparable results and a similar trend of changes through the passes, the average value of which does not exceed 1.54 % and - 1.77 %. The beginning of the continuous layer formation of equivalent stress during roughing rolling has been determined, and, accordingly, the beginning of the deformation penetration through the entire thickness of the semi-rolled product has been also determined that occurs in the pass 6 when reduction equals 14 %.

Load–Velocity Relationship in National Paralympic Powerlifters: A Case Study

2019 ◽  
Vol 14 (4) ◽  
pp. 531-535 ◽  
Author(s):  
Irineu Loturco ◽  
Lucas A. Pereira ◽  
Ciro Winckler ◽  
Weverton L. Santos ◽  
Ronaldo Kobal ◽  
...  
Keyword(s):  
Entire Range ◽  
Bench Press ◽  
Linear Regression Analysis ◽  
Dynamic Strength ◽  
Movement Velocity ◽  
Predictive Equations ◽  
Velocity Relationship ◽  
Strength Tests ◽  
Mean Differences

Purpose: To examine the relationships between different loading intensities and movement velocities in the bench-press exercise (BP) in Paralympic powerlifters. Methods: A total of 17 national Paralympic powerlifters performed maximum dynamic strength tests to determine their BP 1-repetition maximum (1RM) in a Smith-machine device. A linear position transducer was used to measure movement velocity over a comprehensive range of loads. Linear-regression analysis was performed to establish the relationships between the different bar velocities and the distinct percentages of 1RM. Results: Overall, the correlations between bar velocities and %1RM were strong over the entire range of loads (R2 .80–.91), but the precision of the predictive equations (expressed as mean differences [%] between actual and predicted 1RM values) were higher at heavier loading intensities (∼20% for loads ≤70% 1RM and ∼5% for loads ≥70% 1RM). In addition, it seems that these very strong athletes (eg, 1RM relative in the BP = 2.22 [0.36] kg·kg−1, for male participants) perform BP 1RM assessments at lower velocities than those previously reported in the literature. Conclusions: The load–velocity relationship was strong and consistent in Paralympic powerlifters, especially at higher loads (≥70% 1RM). Therefore, Paralympic coaches can use the predictive equations and the reference values provided here to determine and monitor the BP loading intensity in national Paralympic powerlifters.

scholarly journals Validating the Methods to Process the Stress Path in Multiaxial High-Cycle Fatigue Criteria

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 206
Author(s):  
Jan Papuga ◽  
Eva Cízová ◽  
Aleksander Karolczuk
Keyword(s):  
Fatigue Strength ◽  
Equivalent Stress ◽  
Stress Path ◽  
Multiaxial Fatigue ◽  
Moment Of Inertia ◽  
Critical Plane ◽  
Strength Criteria ◽  
Multiaxial Stress State ◽  
The Moment ◽  
Selection Of

The paper discusses one of the key features in the multiaxial fatigue strength evaluation—the procedure in which the stress path is analyzed to provide relevant measures of parameters required by multiaxial criteria. The selection of this procedure affects the complete equivalent stress derived for any multiaxial load combinations. Three major concepts—the minimum circumscribed circle, minimum circumscribed ellipse, and moment of inertia methods—are described. Analytical solutions of their evaluation for multiaxial stress state with components described by harmonic functions are provided. The concepts are validated on available experimental data when included into six different multiaxial fatigue strength criteria. The results show that the moment of inertia results in too conservative results. Differences between both methods of circumscribed entities are much smaller. There are indications however that the minimum circumscribed ellipse solution works better for critical plane criteria and for the criteria based on stress tensor transformation into the Ilyushin deviatoric space. On the other hand, the minimum circumscribed ellipse solution tends to shift integral criteria to the conservative side.

Repeatability of Dynamic Strength Tests

1985 ◽  
Vol 29 (5) ◽  
pp. 517-520 ◽  
Author(s):  
Krishna K. Menon ◽  
Andris Freivalds
Keyword(s):  
Dynamic Strength ◽  
Dynamic Tests ◽  
Strength Measurement ◽  
Strength Tests ◽  
Good Repeatability ◽  
Coefficients Of Variations

The repeatability of dynamic strength tests was examined by calculating coefficients of variations (CV) for the forces exerted on lifting tests using the legs, torso and arms. Static strengths were also measured and compared to dynamic strengths. The CV for dynamic strengths, was in fact slightly lower than for static strengths, 9.79% vs. 10.6%. The correlations between the two types of strength measurements were large (r=.8l) and significant, indicating that along with good repeatability dynamic tests are an acceptable form of employee strength measurement.

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