Evaluation of the Staircase Test Method using Numerical Simulation

2006 ◽  
pp. 517-530
Author(s):  
Major Randall Pollak
Keyword(s):  
Numerical Simulation ◽  
Test Method ◽  
Staircase Test

scholarly journals Fatigue Strength Analysis of S34MnV Steel by Accelerated Staircase Test

2020 ◽  
Vol 10 (1) ◽  
pp. 394-400 ◽  
Author(s):  
I. M. W. Ekaputra ◽  
Rando Tungga Dewa ◽  
Gunawan Dwi Haryadi ◽  
Seon Jin Kim
Keyword(s):  
Standard Deviation ◽  
Fatigue Strength ◽  
Fatigue Limit ◽  
Fatigue Testing ◽  
Reliability Estimation ◽  
Test Method ◽  
Strength Analysis ◽  
Staircase Method ◽  
Staircase Test ◽  
Number Of Cycles

AbstractThis paper presents the reliability estimation of fatigue strength of the material used for crank throw components. The material used for crank throw components is forged S34MnV steel and subsequently heat-treated by normalising and tempering. High cycle fatigue testing under fully reversed cycling (R = −1) was performed to determine the fatigue limit of the material. The staircase test method is used to obtain accurate values of the mean fatigue limit stress until a number of cycles up to 1E7 cycles. Subsequently, the fatigue test results depend strongly on the stress step and are evaluated by the Dixon-Mood formula. The values of mean fatigue strength and standard deviation predicted by the staircase method are 282 MPa and 10.6MPa, respectively. Finally, the reliability of the design fatigue strength in some selected probability of failure is calculated. Results indicate that the fatigue strength determined from accelerated staircase test is consistent with conventional fatigue testing. Furthermore, the proposed method can be applied for the determination of fatigue strength and standard deviation for design optimisation of S34MnV steel.

Numerical simulation and application of entrainment dust collector for fully mechanized mining support based on orthogonal test method

2021 ◽  
Vol 380 ◽  
pp. 553-566
Author(s):  
Wenjing Yin ◽  
Gang Zhou ◽  
Dong Liu ◽  
Qunzhi Meng ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Orthogonal Test ◽  
Test Method ◽  
Dust Collector ◽  
Orthogonal Test Method

Supercritical Carbon Dioxide Centripetal Compressor—Aerodynamic Design and Analysis of Off Design Conditions

2019 ◽  
Vol 5 (4) ◽  
Author(s):  
Xuefei Du ◽  
Dengtao Yu ◽  
Dan Luo ◽  
Diangui Huang
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Supercritical Carbon Dioxide ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Thermal Design ◽  
Test Method ◽  
Characteristic Line ◽  
Supercritical Carbon

Abstract Based on the design of the supercritical carbon dioxide (SCO2) centripetal compressor, this paper adopts the orthogonal design test method to optimize the pear-shaped volute, designs the front guide vane with the third-order Bezier curve, and designs the outlet by the equal section method. The numerical simulation calculation and analysis of the design conditions and variable conditions of the SCO2 centripetal compressor are carried out. The results at design conditions show that the isentropic efficiency is 92%, the pressure ratio is 1.21, and the mass flow rate is 195.9 kg/s, which is close to the thermal design and level simulation results; the results of variable conditions show that the efficiency of the SCO2 centripetal compressor-flow and pressure ratio-flow characteristic line is similar to that of multistage axial flow compressor. The supercritical carbon dioxide centripetal compressor designed in this paper meets the design requirements, and its feasibility is proved through numerical simulation.

scholarly journals Study on Compaction Effect and Process of Reclaimed Soil of Nonmetallic Mines in Xinjiang, China

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Kaikai Wang ◽  
Zizhao Zhang ◽  
Guobin Tang ◽  
Xiaodong Tan ◽  
Qianli Lv ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Land Reclamation ◽  
Simulation Method ◽  
Test Method ◽  
Soil Thickness ◽  
In Situ Test ◽  
Factors Affecting ◽  
Reclaimed Soil ◽  
Different Thickness

Reclaimed soil is the key substrate for land reclamation and ecological restoration in the mine areas. The change of the density of reclaimed soil of the nonmetallic mines in Xinjiang during the land reclamation process was studied in this paper. Firstly, the in situ test method of static load was used to simulate the compaction of reclaimed soil with different thickness of overlying soil by different compaction times of mines reclamation machinery, and field in situ test compaction data were obtained. Then, the numerical simulation method was used to simulate the variation process of displacement and porosity at different depths for different thickness of the reclaimed soil under different compaction conditions. The numerical simulation and the in situ test results verified each other to acquire the compaction process and results of reclaimed soil under different compaction. The results showed that the numerical simulation results were consistent with the in situ test. The reclaimed soil thickness and compaction times were crucial factors affecting the compaction effect of the soil. The difference between the three times compaction and the uncompacted soil was obvious, and the effect of single compaction was weakened with the increase of compaction times. Under the same compaction action, the thicker the soil was, the less obvious the compaction effect would be. In the process of reclamation, the compaction effect of the surface part (at the depth of 10 cm) was visible, and the amount of compression and springback was larger. The research results can provide a reference to the land reclamation of nonmetallic mines in Xinjiang, China.

scholarly journals Numerical Simulation Virtual Test of Torsion Shear for Asphalt Mixture

2019 ◽  
Vol 2019 ◽  
pp. 1-21
Author(s):  
Jun Xie ◽  
Yougang Yang
Keyword(s):  
Numerical Simulation ◽  
Shear Failure ◽  
Failure Process ◽  
Asphalt Mixture ◽  
Test Method ◽  
Reconstruction Method ◽  
Virtual Test ◽  
Torsional Shear ◽  
Shear Process ◽  
Air Void

In order to analyze the torsional shear process of asphalt mixtures in a microscopic view, the numerical simulation of a torsional shear test of an asphalt mixture was carried out by discrete element method. Based on the defects of existing algorithms, the method of random reconstruction of the existing 3D model of the asphalt mixture was improved, and a new reconstruction method was proposed. A 3D numerical model of the asphalt mixture contained irregular-shaped coarse aggregate, mineral gradation, and asphalt mortar; furthermore, the particle algorithm established the air void distribution. Then, the numerical simulation of the asphalt mixture’s torsional shear was completed; in addition, the stress, displacement, and contact of the specimens at each stage were analyzed. The results showed that the stress and displacement in different stages changed greatly with the loading, i.e., the crack generated from a weak point on the surface and then spread to the ends with an oblique angle of about 45°. At the same time, the shear failure process of the asphalt mixture was studied. The virtual test method could accomplish the implementation of the numerical simulation of torsional shear; it also provided a good research method for analysis of the asphalt mixture’s shear failure process.

Numerical Simulation Analysis of Bearing Characteristics on Super-Large Diameter Rock Socketed Pile

2014 ◽  
Vol 580-583 ◽  
pp. 432-435 ◽  
Author(s):  
Cheng Zhong Gong ◽  
Chun Lin He ◽  
Ming Xing Zhu
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Large Diameter ◽  
Flow Analysis ◽  
Test Method ◽  
Main Stress ◽  
Pile Cap ◽  
Pile Caps ◽  
S Curve ◽  
Stress Flow

Wujiang Bridge is located on the Wujiang River in Chongqing Province in China. Based on test method of numerical simulation, the bearing characteristics of this large-diameter rock-socket pile with super-thick pile caps have been analyzed, including pile foundation load-bearing characteristics, pile-soil load sharing, and stress flow analysis of thick pile caps. The results indicated that Q-s curve of this kind of pile is approximate to linear. Under the action of ultimate load, the main load was supported by pile end résistance. And according to main stress distribution of pile cap, there is an obvious spatial truss effect phenomenon in it.

Numerically Testing and Analyzing the Limit Bearing Capacity of Pollution Soil Body

2011 ◽  
Vol 187 ◽  
pp. 535-539
Author(s):  
Li Bo Liu ◽  
An Nan Jiang
Keyword(s):  
Numerical Simulation ◽  
Sulfuric Acid ◽  
Bearing Capacity ◽  
Numerical Method ◽  
Limit Analysis ◽  
Numerical Test ◽  
Test Method ◽  
Analysis Theory ◽  
Soil Foundation ◽  
Complex Foundation

Because actual soil body, especially pollution soil has the complex geotechnical conditions and non-uniformity character, the conventional methods are limited to solve the foundation bearing capacity pressure. The paper proposed an analysis flow of pollution soil foundation bearing capacity evolution, and proposed the numerical test method for pollution soil body combining Fast Lagrange numerical method and limit analysis theory, which utilizes the power ability of numerical simulation and has good flexibility to complex foundation. Using the method to execute a simulation for the pollution soil body of certain sulfuric acid factory, obtained the visual destroy process and got the foundation bearing capacity accurately. And the foundation destroy mechanism is also revealed. The numerical results stated that the proposed method is a good mean to analyze foundation bearing capacity for pollution soil body which has good application prospect.

scholarly journals Concept development of a method for identifying friction coefficients for the numerical simulation of clinching processes

2021 ◽  
Author(s):  
Max Böhnke ◽  
Moritz Rossel ◽  
Christian R. Bielak ◽  
Mathias Bobbert ◽  
Gerson Meschut
Keyword(s):  
Numerical Simulation ◽  
Sheet Metal ◽  
Test Method ◽  
Image Correlation ◽  
Pollutant Emissions ◽  
Friction Coefficients ◽  
Frictional Behavior ◽  
Metal Material ◽  
Metal Materials ◽  
Interface Pressures

AbstractIn order to reduce fuel consumption and thus pollutant emissions, the automotive industry is increasingly developing lightweight construction concepts that are accompanied by an increasing usage of aluminum materials. Due to poor weldability of aluminum in combination with other materials, mechanical joining methods such as clinching were developed and established in series production. In order to predict the relevant characteristics of clinched joints and to ensure the reliability of the process, it is simulated numerically during product development processes. In this regard, the predictive accuracy of the simulated process highly depends on the implemented friction model. In particular, the frictional behavior between the sheet metals as well as between the sheet metal and clinching tools has a significant impact on the geometrical formation of the clinched joint. No testing methods exist that can sufficiently investigate the frictional behavior in sheet materials, especially under high interface pressures, different relative velocities, and long friction paths, while allowing a decoupled consideration of the test parameters. This paper describes the development of further testing concepts based on a proven tribo-torsion test method for determining friction coefficients between sheet metal materials for the simulation of clinching processes. For this purpose, the correlation of interface pressure and the relative velocity between aluminum and steel sheet material in clinching processes is investigated using numerical simulation. Based on these findings, the developed concepts focus on determining friction coefficients at interface pressures of the above materials, yield stress, as well as the reproduction of the occurring friction conditions between sheet metal materials and tool surfaces in clinching processes using tool substitutes. Furthermore, wear investigations between sheet metal material and tool surface were carried out in the friction tests with subsequent EDX analyses of the frictioned tool surfaces. The developed method also allows an optical deformation measurement of the sheet metal material specimen by means of digital image correlation (DIC). Based on a methodological approach, the test setups and the test systems used are explained, and the functionality of the concepts is proven by experimental tests using different sheet metal materials.

Experimental Study on Evaluating High-Pile Wharfs for Real Ship Berthing Impact

2013 ◽  
Vol 671-674 ◽  
pp. 372-379
Author(s):  
Yao Feng Xie ◽  
Wei Qing Tang
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Test Method ◽  
Security Evaluation ◽  
Pile Head ◽  
Structure Form ◽  
Overall Evaluation ◽  
Finite Element Numerical Simulation ◽  
Soil Foundation ◽  
Ship Berthing

High-pile wharf is the most frequently used wharf structure form on soil foundation. However, few researches have been conducted to establish field overall evaluation methods capable of determining the berthing capacity of high-pile wharfs. Based on finite element numerical simulation, the stress-deformation relation, and the equations for loading-deflection relation at the pile head are obtained. The method to test the actual berthing capacity for real ship impact on high-pile wharf，as a direct and effective test method，and the security evaluation of high-pile wharf is put forward. These results can be used for reference to test the actual berthing capacity and to evaluate the security of high-pile wharfs.

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