scholarly journals An R5 Based Creep-Fatigue Critical Flaw Assessment of an In-Service Reformer Piping Tee Using Finite Element Analysis

2014 ◽  
Author(s):  
Phillip E. Prueter ◽  
David J. Dewees ◽  
Robert G. Brown
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Operating Conditions ◽  
Cyclic Plasticity ◽  
Assessment Procedure ◽  
Element Analysis ◽  
Thermal Transients ◽  
Non Linear ◽  
Creep Fatigue ◽  
Critical Flaw

This study employs three dimensional (3D) non-linear, finite element analysis (FEA) to supplement a critical flaw sizing assessment of an in-service reformer piping tee. The analysis is guided by the EDF (Électricité de France) Assessment Procedure R5 (formerly from British Energy Generation LTD. or BEGL) as well as Part 10 of API 579-1/ASME FFS-1. Specifically, Volume 4/5 of R5, which addresses crack growth, is used to determine the largest permissible flaw as a function of operational cycles and time at temperature. Required stresses are generated using FEA as well as the simplified reference stress techniques of R5 as appropriate. The analysis explicitly considers thermal transients, as well as cyclic plasticity. Furthermore, modeling of steady state operating conditions considers creep in the FEA material model. Additionally, creep-fatigue flaw growth is considered for a range of initial defect sizes. The targeted inelastic, non-linear FEA is leveraged to remove significant uncertainty and conservatism, and the simplified techniques of R5 are employed wherever reasonable to give the most efficient analysis possible. This investigation provides estimates of flaw propagation rates based on historical cyclic operation and permits determination of reasonable inspection intervals for the reformer tee in question. Paper published with permission.

Finite Element Analysis of a Locked Bolt With an Initial Crack

2009 ◽  
Author(s):  
Jean Paul Kabche ◽  
Mauri´cio Rangel Pacheco ◽  
Ivan Thesi ◽  
Luiz Carlos Largura
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Operating Conditions ◽  
Material Behavior ◽  
Isotropic Hardening ◽  
Stress Concentrations ◽  
Engineering Structures ◽  
Element Analysis ◽  
Micro Cracks ◽  
Non Linear

Bolted connections are largely employed in various types of engineering structures to transfer loads from one member to another. In particular, the off-shore industry has made extensive use of these connections, predominantly at the sub-sea level. In spite of their advantages, bolted joints are critical regions and may become sources of structural weakness due to large stress concentrations. Under severe operating conditions, micro-cracks can develop in the bolt, creating regions of elevated stress which may significantly reduce the integrity of the connection and ultimately lead to failure. This paper presents the three-dimensional finite element analysis of a steel locked bolt assembly aimed to assess the effect of micro-cracks on the structural integrity of the assembly using the commercial finite element package ANSYS. Non-linear contact between the bolt and nut threads is considered, where frictional sliding between components is allowed. A bi-linear isotropic hardening model is used to account for non-linear material behavior. The assembly is loaded by applying a pre-load of fifty percent of the yield stress of the material, according to the API-6A Norm. Two geometric models are investigated: a healthy locked bolt assembly with no initial cracks; and a damaged model, where a circular crack is introduced at the root of the bolt threads. The effect of the crack size is studied by modeling the crack with three different radius sizes. The J-Integral fracture mechanics methodology was used to study the stress concentrations in the damaged model.

Behaviour of Axially Loaded Composite Wall Panel by Using Finite Element Analysis

2015 ◽  
Vol 815 ◽  
pp. 49-53
Author(s):  
Nur Fitriah Isa ◽  
Mohd Zulham Affandi Mohd Zahid ◽  
Liyana Ahmad Sofri ◽  
Norrazman Zaiha Zainol ◽  
Muhammad Azizi Azizan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Structures ◽  
Element Analysis ◽  
Steel Sheets ◽  
Linear Behavior ◽  
Non Linear ◽  
Composite Wall ◽  
Experimental Values ◽  
Civil Engineering Infrastructure

In order to promote the efficient use of composite materials in civil engineering infrastructure, effort is being directed at the development of design criteria for composite structures. Insofar as design with regard to behavior is concerned, it is well known that a key step is to investigate the influence of geometric differences on the non-linear behavior of the panels. One possible approach is to use the validated numerical model based on the non-linear finite element analysis (FEA). The validation of the composite panel’s element using Trim-deck and Span-deck steel sheets under axial load shows that the present results have very good agreement with experimental references. The developed finite element (FE) models are found to reasonably simulate load-displacement response, stress condition, giving percentage of differences below than 15% compared to the experimental values. Trim-deck design provides better axial resistance than Span-deck. More concrete in between due to larger area of contact is the factor that contributes to its resistance.

Specimen positioning effect on microshear test: Non-linear finite element analysis

2012 ◽  
Vol 28 ◽  
pp. e15-e16
Author(s):  
L.H.A. Raposo ◽  
L.C.M. Dantas ◽  
T.A. Xavier ◽  
A.G. Pereira ◽  
A. Versluis ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Non Linear

Research on the Structural Performance of Large-Tonnage Gantry Crane

2013 ◽  
Vol 823 ◽  
pp. 247-250
Author(s):  
Jie Dong ◽  
Wen Ming Cheng ◽  
Yang Zhi Ren ◽  
Yu Pu Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Calculations ◽  
Complex Structure ◽  
Early Period ◽  
Operating Conditions ◽  
Structural Performance ◽  
Gantry Crane ◽  
Element Analysis ◽  
Design And Manufacture

Because of the huge lifting weight and complex structure of large-tonnage gantry crane and in order to effectively design and review it, this paper aims to carry out a research on its structural performance based on the method of theoretical calculation and finite element analysis. During the early period of design, the method of theoretical calculations is adopted, and after specific design it comes the finite element analysis, so as to get the results of analysis under a variety of operating conditions, which illustrates that the structural design and review of large-tonnage gantry crane based on theoretical calculations and finite element are feasible, and also verifies that the method of finite element is an effective way to find a real dangerous cross-section, thus providing the basis for the design and manufacture of the crane structure.

Dynamic Loading Approach for Structural Evaluation of Ultra Large Container Carriers

2005 ◽  
Author(s):  
Bill Shi ◽  
Donald Liu ◽  
Christopher Wiernicki
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Loading ◽  
Impact Load ◽  
Failure Mechanisms ◽  
Direct Calculation ◽  
Element Analysis ◽  
Design Philosophy ◽  
Non Linear ◽  
Large Container

The emerging global economic needs are driving the designs for the next generation of ocean going vessels. Current ultra-large container carrier (10,000 TEU plus) designs are considerably larger and more complex than any currently in service. Proper and rational classification assessment requires that first principles based direct calculation methods be used to augment the standard classification review. The design philosophy behind the ABS Dynamic Loading Approach enables comprehensive identification of potential failure mechanisms. The scope of the necessary engineering assessment encompass full-ship finite element analysis under non-linear sea loads, spectral fatigue analysis, finite element lashing analysis, free and forced vibration analysis, and transient and impact load analysis. This paper describes key aspects of the DLA design philosophy such as non-linear sea loads, load combinations, various applications derived from full-ship finite element analysis. Several examples are given to highlight some critical failure mechanisms to be considered for ultra-large container carriers.

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