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.

A Comparison of Frequency and Time Domain Fatigue Damage Using the Battelle Structural Stress Methodology

2015 ◽  
Author(s):  
Brian E. Healy
Keyword(s):  
Frequency Domain ◽  
Fatigue Damage ◽  
North Sea ◽  
Time Domain ◽  
Fatigue Analysis ◽  
Structural Stress ◽  
Parallel Time ◽  
Representative Cell ◽  
Shear Plate ◽  
Plate Connection

A frequency domain fatigue analysis using the Battelle structural stress methodology has been performed on a shear plate connection detail typical of a representative cell spar in North Sea service. In parallel, time domain cycle counting of the Battelle structural stress ranges has been performed on the same connection detail. The frequency and time domain fatigue damage computed at various locations is reported and compared. Recommendations regarding the application of the Battelle method to wide-banded spectral fatigue problems are provided.

Hybrid Fatigue Analysis Method for Railway Carbody Structure

2008 ◽  
Vol 44-46 ◽  
pp. 733-738 ◽  
Author(s):  
Bing Rong Miao ◽  
Wei Hua Zhang ◽  
Shou Ne Xiao ◽  
Ding Chang Jin ◽  
Yong Xiang Zhao
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Hybrid Method ◽  
Dynamic Stress ◽  
Stress Test ◽  
Fatigue Analysis ◽  
Railway Vehicle ◽  
Analysis Method ◽  
Structure Dynamic ◽  
Multi Body

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.

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.

Fatigue Damage From High Mode Number Vortex-Induced Vibration

2006 ◽  
Author(s):  
J. Kim Vandiver ◽  
Susan B. Swithenbank ◽  
Vivek Jaiswal ◽  
Vikas Jhingran
Keyword(s):  
Fatigue Damage ◽  
Field Experiments ◽  
Higher Harmonics ◽  
Vortex Induced Vibration ◽  
Third Harmonic ◽  
The Third ◽  
Damage Rate ◽  
Surface Vessels ◽  
Vortex Shedding Frequency ◽  
First Time

This paper presents results from two field experiments using long flexible cylinders, suspended vertically from surface vessels. The experiments were designed to investigate vortex-induced vibration (VIV) at higher than tenth mode in uniform and sheared flows. The results of both experiments revealed significant vibration energy at the expected Strouhal frequency (referred to in this paper as the fundamental frequency) and also at two and three times the Strouhal frequency. Although higher harmonics have been reported before, this was the first time that the contribution to fatigue damage, resulting from the third harmonic, could be estimated with some certainty. This was enabled by the direct measurement of closely spaced strain gauges in one of the experiments. In some circumstances the largest RMS stress and fatigue damage due to VIV are caused by these higher harmonics. The total fatigue damage rate including the third harmonic is shown to be up to forty times greater than the damage rate due to the vibration at the fundamental vortex-shedding frequency alone. This dramatic increase in damage rate due to the third harmonic appears to be associated with a narrow range of reduced velocities in regions of the pipe associated with significant flow-induced excitation.

A Case Study Comparison of Surface Extrapolation and Battelle Structural Stress Methodologies

2004 ◽  
Author(s):  
Brian E. Healy
Keyword(s):  
Convergence Analysis ◽  
Hot Spot ◽  
Structural Stress ◽  
Hot Spot Stress ◽  
Side Shell

A case study comparison of 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. Computations of hot spot stress via either method are consistent with current recommended practice. Convergence analysis to determine the hot spot stresses that best serve as fatigue parameters and a fatigue comparison that employs hot spot stresses from the convergence analysis have been executed at various locations around the detail. Results are reported and discussed.

Effect of Wave Induced Loading and Line Loading in Fully Stochastic Fatigue Assessment for West Africa FPSO

2004 ◽  
Author(s):  
T. H. Park ◽  
J. H. Lee ◽  
J. W. Cho ◽  
H. S. Shin
Keyword(s):  
West Africa ◽  
Fatigue Damage ◽  
Bending Moment ◽  
Ship Motions ◽  
Piping System ◽  
Site Specific ◽  
Fatigue Assessment ◽  
Loading Effects ◽  
Wave Induced ◽  
Side Shell

The fatigue assessment for a caisson of the interface between a caisson and a FPSO hull has been performed based on the FMS (Fatigue Methodology Specification) [1]. Investigation is focused on the various loading effects including inertia loading due to ship motions from a site specific swell, sea and line loading from the submerged caisson connected to the side shell of FPSO. The fully stochastic method was used for estimating damage levels from wave loadings. The component-based method was used for line loading effects. The two kinds of results from each case were combined the variance and mean period combination. For the inertia loading, it is shown that a hull deforming due to vertical bending moment is the principal effect for a fatigue assessment. For the line loading, it is found that the loading effect due to the submerged piping system connected to the side shell of FPSO is not significant for the fatigue of the side shell supporting structure. In conclusion, the fatigue damage from the site-specific swell is dominant effect among overall fatigue damage components of FPSO in the specific site condition of West Africa.

Method B Fatigue Screening in ASME BPV Code, Section VIII, Division 2, Part 5

2019 ◽  
Author(s):  
Kenneth Kirkpatrick ◽  
Christopher R. Johnson ◽  
J. Adin Mann
Keyword(s):  
Fatigue Damage ◽  
Pressure Vessel ◽  
Fatigue Analysis ◽  
Damage Factor ◽  
Simple Method ◽  
Mechanical Loads ◽  
Penalty Factor ◽  
Section Viii ◽  
Cyclic Service ◽  
Division 2

Abstract ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Division 2, Part 5 Method B fatigue screening is intended to be a quick and simple method that is sufficiently conservative to screen components in cyclic service thus not requiring detailed fatigue analysis. The method assesses pressure, thermal, and mechanical loads separately. The basis for each portion of the method is discussed along with an alternative bases for the assessments. Each assessment is reformulated as a fatigue damage factor and all variables are provided so that the intent of each equation is clearly identifiable. A penalty factor will be included in each equation rather than assuming one penalty for all designs, the reformulation creates penalty for non-fatigue resistant designs and reduces the penalty for fatigue resistant designs. Examples are given showing the potentially non-conservative results if a summed damage is not used.

Fatigue Analysis of Free Spanning Pipelines Subjected to Vortex Induced Vibrations

2013 ◽  
Author(s):  
F. Van den Abeele ◽  
F. Boël ◽  
M. Hill
Keyword(s):  
Fatigue Damage ◽  
Oil And Gas ◽  
Flow Direction ◽  
Cross Flow ◽  
Fatigue Analysis ◽  
Sensitivity Analyses ◽  
Vortex Induced Vibration ◽  
Vortex Induced Vibrations ◽  
Offshore Industry ◽  
Girth Welds

Vortex induced vibration is a major cause of fatigue failure in submarine oil and gas pipelines and steel catenary risers. Even moderate currents can induce vortex shedding, alternately at the top and bottom of the pipeline, at a rate determined by the flow velocity. Each time a vortex sheds, a force is generated in both the in-line and cross-flow direction, causing an oscillatory multi-mode vibration. This vortex induced vibration can give rise to fatigue damage of submarine pipeline spans, especially in the vicinity of the girth welds. In this paper, an integrated numerical framework is presented to predict and identify free spans that may be vulnerable to fatigue damage caused by vortex induced vibrations (VIV). An elegant and efficient algorithm is introduced to simulate offshore pipeline installation on an uneven seabed. Once the laydown simulation has been completed, the free spans can be automatically detected. When the fatigue screening for both inline and cross-flow VIV indicates that a particular span may be prone to vortex induced vibrations, a detailed fatigue analysis is required. Amplitude response models are constructed to predict the maximum steady state VIV amplitudes for a given pipeline configuration (mechanical properties) and sea state (hydrodynamic parameters). The vibration amplitudes are translated into corresponding stress ranges, which then provide an input for the fatigue analysis. A case study from the offshore industry is presented, and sensitivity analyses are performed to study the influence of the seabed conditions, where special emphasis is devoted on the selection of pipe soil interaction parameters.

Sign in / Sign up

Export Citation Format

Share Document