Equilibrium-equivalent structural stress approach to fatigue analysis of a rectangular hollow section joint

2005 ◽  
Vol 27 (1) ◽  
pp. 85-94 ◽  
Author(s):  
H KYUBA
Keyword(s):  
Fatigue Analysis ◽  
Structural Stress ◽  
Hollow Section

Strength-based design of a sunflower stalk cutter machine design using finite element analysis and experimental validation

2021 ◽  
pp. 095440622110597
Author(s):  
Gürkan İrsel
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Analysis ◽  
Strain Gage ◽  
Experimental Validation ◽  
Experimental Studies ◽  
Fatigue Analysis ◽  
Structural Stress ◽  
Element Analysis ◽  
Strength Based

In this study, the total algorithm of the strength-based design of the system for mass production has been developed. The proposed algorithm, which includes numerical, analytical, and experimental studies, was implemented through a case study on the strength-based structural design and fatigue analysis of a tractor-mounted sunflower stalk cutting machine (SSCM). The proposed algorithm consists of a systematic engineering approach, material selection and testing, design of the mass criteria suitability, structural stress analysis, computer-aided engineering (CAE), prototype production, experimental validation studies, fatigue calculation based on an FE model and experimental studies (CAE-based fatigue analysis), and an optimization process aimed at minimum weight. Approximately 85% of the system was designed using standard commercially available cross-section beams and elements using the proposed algorithm. The prototype was produced, and an HBM data acquisition system was used to collect the strain gage output. The prototype produced was successful in terms of functionality. Two- and three-dimensional mixed models were used in the structural analysis solution. The structural stress analysis and experimental results with a strain gage were 94.48% compatible in this study. It was determined using nCode DesignLife software that fatigue damage did not occur in the system using the finite element analysis (FEA) and experimental data. The SSCM design adopted a multi-objective genetic algorithm (MOGA) methodology for optimization with ANSYS. With the optimization solved from 422 iterations, a maximum stress value of 57.65 MPa was determined, and a 97.72 kg material was saved compared to the prototype. This study provides a useful methodology for experimental and advanced CAE techniques, especially for further study on complex stress, strain, and fatigue analysis of new systematic designs desired to have an optimum weight to strength ratio.

A Comparison of the Surface Extrapolation and Battelle Structural Stress Methodologies as Applied to a Spectral Fatigue Analysis of a Representative FPSO Structural Detail

2007 ◽  
Author(s):  
Brian E. Healy
Keyword(s):  
Fatigue Damage ◽  
Fatigue Analysis ◽  
Structural Stress ◽  
Structural Detail ◽  
First Time ◽  
Side Shell

A spectral fatigue analysis using both the surface extrapolation and Battelle structural stress methodologies has been performed on a side shell connection detail typical of a representative FPSO or tanker vessel. This marks the first time the Battelle method has been adapted to spectral fatigue and details of the implementation are presented for narrow banded applications. Fatigue damage at the toe along a number of weld lines is computed for a variety of surface extrapolation strategies and Battelle method options. Results are reported and compared. Recommendations regarding the application of the Battelle method to spectral fatigue are made.

Structural Stress Based Fatigue Analysis Method for Plane Steel Gate

2013 ◽  
Vol 838-841 ◽  
pp. 314-318
Author(s):  
Hang Gang Guo ◽  
Jin Zhang ◽  
Yang Zhang ◽  
Wei Zhang
Keyword(s):  
Fatigue Failure ◽  
Fatigue Analysis ◽  
Structural Stress ◽  
Analysis Method ◽  
Fatigue Design ◽  
Life Evaluation ◽  
Water Head ◽  
Asme Code ◽  
Rigid Connection ◽  
Steel Gate

Though fatigue failure is often happened in steel gate, fatigue design has not yet been included in design or evaluation standards in China. In this paper, analytical theory based structural stress method and structural stress based fatigue analysis method are combined and employed for fatigue life evaluation of plane steel gate. The variation of water head is taken into consideration for the conditions of gate running and resting. In order to give a valid evaluation, the weld located among all components is considered as rigid connection when calculating structural stress. Master S-N curve in ASME code is used for life evaluation. Example shows the method can be used for fatigue analysis of plane steel gate, and can be used to identify fatigue failure zone.

A Study on Fatigue Analysis Procedure of Nuclear Welded Structures Based on Structural Stress and Fracture Mechanics Approach

2004 ◽  
Author(s):  
Jong-Sung Kim ◽  
Tae-Eun Jin
Keyword(s):  
Fatigue Crack ◽  
Fracture Mechanics ◽  
Crack Initiation ◽  
Growth Models ◽  
Fatigue Crack Initiation ◽  
Fatigue Analysis ◽  
Analysis Procedure ◽  
Thickness Variation ◽  
Structural Stress ◽  
Structural Stresses

The mesh-insensitive structural stress procedure by Dong is modified to apply to the welded joints with local thickness variation and inignorable shear/normal stresses along local discontinuity surface. Validity of the modified mesh-insensitive structural stress procedure is identified comparing the structural stresses calculated for various FE models. Fatigue crack initiation cycles are determined by using the structural stresses and the various fatigue crack growth models. Fatigue test is performed to identify the validity of the fatigue analysis results. Finally, as a result of comparison between test and analysis results, it is found that the structural stress/fracture mechanics approach is valid for fatigue analysis and the requirements for development of a new fatigue crack initiation analysis procedure are presented.

Applicability Evaluation of SS (Structural Stress) Method on Actual Project

2008 ◽  
Vol 580-582 ◽  
pp. 633-636 ◽  
Author(s):  
Kwang Seok Kim ◽  
Joong Kyoo Kang ◽  
Joo Ho Heo ◽  
Sung Geun Lee
Keyword(s):  
Fatigue Life ◽  
Hot Spot ◽  
Fatigue Analysis ◽  
Correlation Factor ◽  
Structural Stress ◽  
Hot Spot Stress ◽  
Notch Stress ◽  
Loading Case ◽  
Application Data ◽  
Applicability Evaluation

The structural stress (SS) method developed by BATTELLE has been studied based on small or mid-size scale specimens. In order to apply the new method, such as SS, on an actual project, it should have application results on actual project. However, SS method didn’t have a lot of application data compared to class procedure using hot spot stress (HSS). In order to find out whether the SS method, for the evaluation of fatigue life, can give reasonable results when it is applied under the same loading suggested by classification societies, it was compared with fatigue lives derived by class. ABS & DNV’s simplified fatigue analysis method were adopted to check the validity of SS method. Before applying complicated loading of class, static loading case was applied, since the class method has their own correlation factor for wave loading. And then, simplified fatigue analysis was performed with more complicated loading cases. From the results of fatigue life calculation, it can be said that SS shows reasonable fatigue lives with respect to HSS or notch stress based fatigue lives.

Fatigue Analysis of Nuclear Welded Structures Based on Structural Stress and Elasto-Plastic Fracture Mechanics Approach

2005 ◽  
Vol 297-300 ◽  
pp. 774-780
Author(s):  
Jong Sung Kim ◽  
Tae Eun Jin
Keyword(s):  
Fracture Mechanics ◽  
Fatigue Test ◽  
Growth Models ◽  
Fatigue Analysis ◽  
Thickness Variation ◽  
Structural Stress ◽  
Test Results ◽  
Linear Elastic ◽  
Elastic Fracture ◽  
Stress Concentration Factors

In the paper, the validity of the modified mesh-insensitive SS (structural stress) procedure to apply to the welded joints with local thickness variation is identified via the comparison of SCFs (stress concentration factors) calculated for various FE (finite element) models. FCI (fatigue crac kinitiation) cycles are determined by using the SS/EPFM (elasto-plastic fracture mechanics) approach and the various fatigue crack growth models. Fatigue test is performed to identify the validity of the fatigue analysis results. Finally, as a result of comparison among test and various analysis results, it is found that the SS/FM (fracture mechanics) approach agrees well with the fatigue test results over all cycle regions and the SS/EPFM approach is more reliable than the SS/LEFM (linear elastic fracture mechanics) approach.

A Robust Structural Stress Method for Fatigue Analysis of Offshore/Marine Structures

2005 ◽  
Vol 127 (1) ◽  
pp. 68-74 ◽  
Author(s):  
P. Dong
Keyword(s):  
Finite Element ◽  
Fatigue Behavior ◽  
Fatigue Analysis ◽  
Finite Element Mesh ◽  
Complex Structures ◽  
Structural Stress ◽  
Marine Structures ◽  
Element Mesh ◽  
Fatigue Design ◽  
Structural Stresses

Recent rapid advances in developing mesh-insensitive structural stress methods are summarized in this paper. The new structural stress methods have been demonstrated to be effective in reliably calculating structural stresses that can be correlated with fatigue behavior from simple weld details to complex structures. As a result, a master S–N curve approach has been developed and validated by a large amount of weld S–N data in the literature. The applications of the present structural stress methods in a number of joint types in offshore/marine structures will be illustrated in this paper. The implications on future applications in drastically simplifying fatigue design and evaluation for offshore/marine structures will also be discussed, particularly for using very coarse finite element mesh designs in ship structures.

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