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

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.

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4190
Author(s):  
Jincheng Zheng ◽  
Peiwei Zhang ◽  
Dahai Zhang ◽  
Dong Jiang

A multi-scale fatigue analysis method for braided ceramic matrix composites (CMCs) based on sub-models is developed in this paper. The finite element shape function is used as the interpolation function for transferring the displacement information between the macro-scale and meso-scale models. The fatigue failure criterion based on the shear lag theory is used to implement the coupling calculation of the meso-scale and micro-scale. Combining the meso-scale cell model and the fatigue failure criterion based on the shear lag theory, the fatigue life of 2D SiC/SiC is analyzed. The analysis results are in good agreement with the experimental results, which proves the accuracy of the meso-scale cell model and the fatigue life calculation method. A multi-scale sub-model fatigue analysis method is used to study the fatigue damage of 2D SiC/SiC stiffened plates under random tension–tension loads. The influence of the sub-models at different positions in the macro-model element on the analysis results was analyzed. The results shows that the fatigue analysis method proposed in this paper takes into account the damage condition of the meso-structured of composite material, and at the same time has high calculation efficiency, and has low requirements for modeling of the macro finite element model, which can be better applied to the fatigue analysis of CMCs structure.


Author(s):  
Timothy M. Adams

In conducting a Class 1 piping analysis per the simplified rules of the ASME Boiler and Pressure Vessel Code, Section III, Division 1, Article NB-3600, a fatigue analysis is required per paragraph NB-3653 for both Service Level A and Service Level B. The fatigue analysis provides two options. The options are dependent on Equation 10 of subparagraph NB-3653.1. If this equation is met for a given load set pair under consideration, then the analysis proceeds directly to subparagraphs NB-3653.2 through NB-3653.5. If however, Equation 10 is exceeded, the Code allows the use of a simplified Elastic Plastic Analysis as delineated in subparagraph NB-3653.6. The first requirement of NB-3653.6 is that both Equation 12 and Equation 13 must be met. The changes in the seismic design in the last 25+ years have not been appropriately reflected in the subparagraph NB-3653.6(b) Equation 13. Also, the Code provides no clear guidance on seismic anchor motions in paragraph NB-3650. In 2012 ASME Code Committees undertook an action to address these issues. This paper provides the background and basis for Code changes that are anticipated will be implemented in the near future in paragraph NB-3653.6 of the ASME Boiler and Pressure Vessel Code, Section III, Division 1 that will address both of these issues. This implementation will make the Elastic Plastic Fatigue rules of NB-3653.6 consistent with the design by analysis approach of NB-3228.5.


2005 ◽  
Vol 127 (1) ◽  
pp. 68-74 ◽  
Author(s):  
P. Dong

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.


2012 ◽  
Vol 229-231 ◽  
pp. 621-624
Author(s):  
Chao Yi Ding ◽  
Gang Qiang Li ◽  
Hong Che Guo

This article combines with finite element method and the rain flow count method, which is using the nominal stress method developed a wind turbine used for structural fatigue analysis method, with 2.0 MW wind and machine hub to analyze the fatigue, calculated the operation lifespan fatigue load of wind turbine in the 20 years. By choosing the hot point of hub, analyzes the wheels fatigue damage characteristics. The calculation results show that: the selection of hot point wheels meet with the requirements of GL standard Fatigue design. This paper can be used in large wind turbine development design and in the process of production design authentication.


2012 ◽  
Vol 550-553 ◽  
pp. 3082-3087
Author(s):  
Xing Ye Su ◽  
Qin Li ◽  
Hong Mei Wang

With the rapid development of petrochemical industry, the operation condition of pressure vessels under the alternating load was increasing and the probability of fatigue failure was also on the rise. As a result, pressure vessel fatigue analysis is gaining the designer's attention. This paper describes the key steps and techniques of the fatigue analysis of pressure vessel based on Workbench platform using the lock hopper of the coal chemical industry as an example.


2008 ◽  
Vol 44-46 ◽  
pp. 733-738 ◽  
Author(s):  
Bing Rong Miao ◽  
Wei Hua Zhang ◽  
Shou Ne Xiao ◽  
Ding Chang Jin ◽  
Yong Xiang Zhao

Railway vehicle structure fatigue life consumption monitoring can be used to determine fatigue damage by directly or indirectly monitoring the loads placed on critical vehicle components susceptible to failure from fatigue damage. The sample locomotive carbody structure was used for this study. Firstly, the hybrid fatigue analysis method was used with Multi-Body System (MBS) simulation and Finite Element Method (FEM) for evaluating the carbody structure dynamic stress histories. Secondly, the standard fatigue time domain method was used in fatigue analysis software FE-FATIGUE and MATLAB WAFO (Wave Analysis for Fatigue and Oceanography) tools. And carbody structure fatigue life and fatigue damage were predicted. Finally, and carbody structure dynamic stress experimental data was taken from this locomotive running between Kunming-Weishe for this analysis. The data was used to validate the simulation results based on hybrid method. The analysis results show that the hybrid method prediction error is approximately 30.7%. It also illustrates that the fatigue life and durability of the locomotive can be predicted with this hybrid method. The results of this study can be modified to be representative of the railway vehicle dynamic stress test.


Author(s):  
Gürkan İrsel

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.


Author(s):  
Omesh K. Chopra

The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components and specifies fatigue design curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Existing fatigue strain–vs.–life (ε–N) data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. This paper reviews the existing fatigue ε–N data for austenitic stainless steels in LWR coolant environments. The effects of key material, loading, and environmental parameters, such as steel type, strain amplitude, strain rate, temperature, dissolved oxygen level in water, and flow rate, on the fatigue lives of these steels are summarized. Statistical models are presented for estimating the fatigue ε–N curves for austenitic stainless steels as a function of the material, loading, and environmental parameters. Two methods for incorporating environmental effects into the ASME Code fatigue evaluations are presented. Data available in the literature have been reviewed to evaluate the conservatism in the existing ASME Code fatigue design curves.


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