scholarly journals Using Commercially Available Finite Element Software For Fatigue Analysis

2020 ◽  
Author(s):  
Cyrus Hagigat
Keyword(s):  
Finite Element ◽  
Fatigue Analysis ◽  
Finite Element Software

Application of Finite Element Software in Fatigue Analysis of the Welded Joints

2011 ◽  
Vol 337 ◽  
pp. 372-378
Author(s):  
Wen Xue Fan ◽  
Fu Rong Chen
Keyword(s):  
Finite Element ◽  
Welded Joints ◽  
Large Scale ◽  
Fatigue Analysis ◽  
Static Fatigue ◽  
Suitable Model ◽  
Finite Element Software ◽  
Welded Structure ◽  
Finite Element Technology ◽  
Vibration Fatigue

Based on the fatigue behaviors of welded structure and the distinction between static fatigue and vibration fatigue and sound fatigue, the general fatigue analysis methods of static fatigue and vibration fatigue are introduced in this paper, such as nominal stress method, structure stress method, hot stress method and power spectral density method. Especially application status and common software of finite element analysis are expounded and analyzed in fatigue analysis of the welded joint. In recent years, finite element technology is applied widely on analysis all kinds of welded joints, the main problems include two points, built suitable model and generated reasonable mesh. Nowadays, finite element software has many kinds of usage and different software has different functions. According to the stress analysis process of static fatigue and vibration fatigue, three large-scale general finite element software ANSYS, MSC.NASTRAN/PANTRAN and ABAQUS, some comparative analyses have been done in building model, partitioning mesh and applying method At last some important conclusions are given. Different finite element software has equivalent development background and reliable analysis performance. Different finite element software have different application platform. In order to get better analysis result, each other’s merits are drew from different software and matched with the application.

scholarly journals Fatigue Analysis Design Approach, Manufacturing and Implementation of a 500 kW Wind Turbine Main Load Frame

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3581
Author(s):  
Ahmet Selim Pehlivan ◽  
Mahmut Faruk Aksit ◽  
Kemalettin Erbatur
Keyword(s):  
Finite Element ◽  
Wind Turbine ◽  
Implementation Process ◽  
Dynamic Strength ◽  
Fatigue Analysis ◽  
Safety Factors ◽  
Safety Standards ◽  
Finite Element Software ◽  
Fatigue Rupture ◽  
Load Frame

The main load frame of a wind turbine is the primary mount for all nacelle equipment and is used as the principal load transmitter. This frame should have a reliable fatigue safety rating because it is a load-bearing component. In this work, the fatigue life design, manufacturing and implementation process for the main load frame of a 500 kW wind turbine are studied. The weight of the main load frame and static safety factors are preserved while the cyclic life of the bedplate is kept infinite. Modified Goodman theory is applied to achieve an effective fatigue design using a commercial finite element software package. Analytical calculations are carried out to obtain the safety factors of the bedplate and dynamic strength of the materials. A finite element approach is employed to perform stress analysis. Stress oscillations are established for both welded and cast parts of the hybrid bedplate, and the maximum and minimum stress values are established. Fatigue safety factors are calculated via fatigue analysis iterations. The obtained safety factors are adequate from the perspective of commonly accepted fatigue safety standards. Welding and casting techniques are applied together for manufacturing of the frame. On-site testing indicates that the wind turbine does not show any signs of fatigue. Rupture, cracks, and abrupt accelerometer reading variations are not observed.

A Proposal to Consider Cycle Counting Methods for Fatigue Analysis of Nuclear and Conventional Power Plant Components

2016 ◽  
Author(s):  
Felippe M. S. Costa ◽  
José Luiz F. Freire ◽  
Jürgen Rudolph ◽  
José Eduardo Maneschy
Keyword(s):  
Finite Element ◽  
Analytical Solution ◽  
Time History ◽  
Peak Stress ◽  
Fatigue Analysis ◽  
Transient Temperature ◽  
Stress Range ◽  
Structural Components ◽  
Finite Element Software ◽  
Asme Code

This paper points out some relevant aspects of the simplified elasto-plastic fatigue analysis as addressed in the ASME Code Section III Subsection NB and its application to two structural components that are subjected to a slow or to a fast thermal transient. The structural components considered are a thick-walled pipe and a nozzle-to-vessel junction. For the case of the thick-walled pipe, a closed form analytical solution proposed by Albrecht for pipes subjected transient temperature loading was implemented and its results were compared to coupled thermal and mechanical finite element analyses using a commercial finite element software. The application of the analytical solution allows for an optimization of the time consumed to obtain the stresses that occur across the thickness of the pipe as a function of time, i.e. the membrane plus bending plus peak stress range, Sp. The analytical solution equally allows for the linearization of the stress components actuating along the pipe thickness for all time steps considered within the thermal stress solution. This yields the membrane plus bending stress range, Sn, and allows for a design code conforming plasticity correction by means of Ke factors. In the considered case of the nozzle-to-vessel junction, a finite element solution was used. It was one aim of the study to point out, that under fast transients loading situations the relevant stresses Sp and Sn do not necessarily coincide with each other. In the ASME Code the alternating stress Sa is a function of the factor Ke and of the range of Sp, with Ke being a function of the range of Sn and of the material properties. Consequently, a non-conservative fatigue analysis may result in the case of performing cycle counting only based on the time history of the critical Sp values and simply assigning the corresponding Sn and Ke values. This paper exemplifies one of those cases and proposes a method to overcome this problem.

Influence of Intermediate Course Gradation Type on Anti-Fatigue Performance of the Asphalt Pavement Structure

2014 ◽  
Vol 684 ◽  
pp. 191-194
Author(s):  
Zhao Hui Sun ◽  
Li Guang Chen ◽  
Guo Feng Yang ◽  
Bao Yang Yu
Keyword(s):  
Finite Element ◽  
Asphalt Mixture ◽  
Fatigue Analysis ◽  
Base Layer ◽  
Rigid Base ◽  
Course Materials ◽  
Finite Element Software ◽  
Calculation Results ◽  
Pavement Structure ◽  
Asphalt Concrete Pavement

Three grading types of asphalt mixture are designed and respectively placed in intermediate course of asphalt concrete pavement with a typical semi-rigid base layer, the pavement structure model is established by the application of finite element software, the tensile stress at the bottom of intermediate course is analyzed under the wheel pressure of 1.5MPa, the finite element calculation results are led to the fatigue analysis software nSoft, the fatigue analysis results of intermediate course materials are obtained. The results show that the design gradation AC-20 mixture has excellent fatigue resistance in the pavement structure layer.

scholarly journals Low-Cycle Fatigue Crack Initiation Simulation and Life Prediction of Powder Superalloy Considering Inclusion-Matrix Interface Debonding

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4018
Author(s):  
Shuming Zhang ◽  
Yuanming Xu ◽  
Hao Fu ◽  
Yaowei Wen ◽  
Yibing Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Crack Initiation ◽  
Life Prediction ◽  
Damage Mechanics ◽  
Low Cycle Fatigue ◽  
Fatigue Crack Initiation ◽  
Fatigue Loading ◽  
Interface Debonding ◽  
Damage Evolution Equation ◽  
Finite Element Software

From the perspective of damage mechanics, the damage parameters were introduced as the characterizing quantity of the decrease in the mechanical properties of powder superalloy material FGH96 under fatigue loading. By deriving a damage evolution equation, a fatigue life prediction model of powder superalloy containing inclusions was constructed based on damage mechanics. The specimens containing elliptical subsurface inclusions and semielliptical surface inclusions were considered. The CONTA172 and TARGE169 elements of finite element software (ANSYS) were used to simulate the interfacial debonding between the inclusions and matrix, and the interface crack initiation life was calculated. Through finite element modeling, the stress field evolution during the interface debonding was traced by simulation. Finally, the effect of the position and shape size of inclusions on interface debonding was explored.

Effect of crack on free vibration of a pre-stressed curved plate

2021 ◽  
pp. 095440622199486
Author(s):  
Can Gonenli ◽  
Hasan Ozturk ◽  
Oguzhan Das
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Natural Frequency ◽  
Present Model ◽  
Mode Shapes ◽  
Load Parameter ◽  
Flexible Plate ◽  
Cantilever Plate ◽  
Finite Element Software ◽  
Aspect Ratios

In this study, the effect of crack on free vibration of a large deflected cantilever plate, which forms the case of a pre-stressed curved plate, is investigated. A distributed load is applied at the free edge of a thin cantilever plate. Then, the loading edge of the deflected plate is fixed to obtain a pre-stressed curved plate. The large deflection equation provides the non - linear deflection curve of the large deflected flexible plate. The thin curved plate is modeled by using the finite element method with a four-node quadrilateral element. Three different aspect ratios are used to examine the effect of crack. The effect of crack and its location on the natural frequency parameter is given in tables and graphs. Also, the natural frequency parameters of the present model are compared with the finite element software results to verify the reliability and validity of the present model. This study shows that the different mode shapes are occurred due to the change of load parameter, and these different mode shapes cause a change in the effect of crack.

Numerical solutions for strain-softening surrounding rock under three-dimensional principal stress condition

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sheng Yu-ming ◽  
Li Chao ◽  
Xia Ming-yao ◽  
Zou Jin-feng
Keyword(s):  
Finite Element ◽  
Principal Stress ◽  
Stress Condition ◽  
Strain Softening ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Strength Criterion ◽  
Surrounding Rock ◽  
Flow Rule ◽  
Finite Element Software

Abstract In this study, elastoplastic model for the surrounding rock of axisymmetric circular tunnel is investigated under three-dimensional (3D) principal stress states. Novel numerical solutions for strain-softening surrounding rock were first proposed based on the modified 3D Hoek–Brown criterion and the associated flow rule. Under a 3D axisymmetric coordinate system, the distributions for stresses and displacement can be effectively determined on the basis of the redeveloped stress increment approach. The modified 3D Hoek–Brown strength criterion is also embedded into finite element software to characterize the yielding state of surrounding rock based on the modified yield surface and stress renewal algorithm. The Euler implicit constitutive integral algorithm and the consistent tangent stiffness matrix are reconstructed in terms of the 3D Hoek–Brown strength criterion. Therefore, the numerical solutions and finite element method (FEM) models for the deep buried tunnel under 3D principal stress condition are presented, so that the stability analysis of surrounding rock can be conducted in a direct and convenient way. The reliability of the proposed solutions was verified by comparison of the principal stresses obtained by the developed numerical approach and FEM model. From a practical point of view, the proposed approach can also be applied for the determination of ground response curve of the tunnel, which shows a satisfying accuracy compared with the measuring data.

Research on Mesh Optimization of the Finite Element Calculation about Three-Dimensional Foundation Pit

2012 ◽  
Vol 487 ◽  
pp. 855-859
Author(s):  
Shi Lun Feng ◽  
Yu Ming Zhou ◽  
Pu Lin Li ◽  
Jun Li ◽  
Zhi Yong Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Complex Geometry ◽  
Three Dimensional ◽  
Mesh Optimization ◽  
Design Calculation ◽  
Foundation Pit ◽  
3D Design ◽  
Finite Element Software ◽  
Core Language ◽  
Grid Division

Abaqus finite element software can implement three-dimensional excavation design calculation, so authors used Python of Abaqus core language made the 3D design of foundation pit supporting program come ture and also did intensive study of mesh optimization during the process. Authors also did intensive comparison and analysis about grid division of the complex geometry foundation pit, through a regularization partion about a variety of special-shaped pit, we made the automatic division about the structural grid of all kinds of shapes foundation pit successful. On this basis, we achieved better calculation effects of the model. The article will introduce problems about optimization of grid in procedure.

scholarly journals Characterization of Mechanical Heterogeneity in Dissimilar Metal Welded Joints

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4145
Author(s):  
He Xue ◽  
Zheng Wang ◽  
Shuai Wang ◽  
Jinxuan He ◽  
Hongliang Yang
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Welded Joints ◽  
Structural Integrity ◽  
Material Interfaces ◽  
Mechanical Heterogeneity ◽  
Finite Element Software ◽  
Dissimilar Metal ◽  
Stress Changes

Dissimilar metal welded joints (DMWJs) possess significant localized mechanical heterogeneity. Using finite element software ABAQUS with the User-defined Material (UMAT) subroutine, this study proposed a constitutive equation that may be used to express the heterogeneous mechanical properties of the heat-affected and fusion zones at the interfaces in DMWJs. By eliminating sudden stress changes at the material interfaces, the proposed approach provides a more realistic and accurate characterization of the mechanical heterogeneity in the local regions of DMWJs than existing methods. As such, the proposed approach enables the structural integrity of DMWJs to be analyzed in greater detail.

Analysis of Pipe-Soil Interaction for a Miniature Pipejacking

2006 ◽  
Vol 22 (3) ◽  
pp. 213-220 ◽  
Author(s):  
K. J. Shou ◽  
F. W. Chang
Keyword(s):  
Finite Element ◽  
Failure Mechanism ◽  
Physical Modeling ◽  
Driving Force ◽  
Numerical Models ◽  
Surface Subsidence ◽  
Finite Element Software

AbstractIn this study, physical and numerical models were used to analyze pipe-soil interaction during pipejacking work. After calibrating with the physical modeling results, the finite element software ABAQUS [1] was used to study the pipejacking related behavior, such as surface subsidence, failure mechanism, pipe-soil interaction, etc. The results show that the driving force in the tunnelling face is very important and critical for pipejacking. Surface subsidence is mainly due to the lack of driving force, however, excessive driving force could cause the unfavorable surface heaving problem. It also suggests that the depth of the pipe is critical to determine a proper driving force to stabilize the tunnelling face.

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