Residual Strength Analysis of Stiffened Aluminum Panels with Widespread Fatigue Damage

2008 ◽  
Vol 33-37 ◽  
pp. 291-296
Author(s):  
Zhong Li ◽  
Sen Ge ◽  
Guo Zhi Lv ◽  
Li Chen ◽  
Hui Liang Ding
Keyword(s):  
Finite Element Method ◽  
Fatigue Damage ◽  
Residual Strength ◽  
Strength Analysis ◽  
Engineering Practice ◽  
Stiffened Panels ◽  
Acceptable Accuracy ◽  
Important Concern ◽  
Aluminum Panels ◽  
Good Agreement

Widespread fatigue damage (WFD) is an important concern of aging aircrafts. Residual strength of stiffened panels with widespread fatigue damage was evaluated by an engineering approach and a finite element method respectively. Nine stiffened panels with three types of damage were tested for their residual strength. The predictions are in good agreement with the experiment results and it is shown the methods could be used in an engineering practice for the residual strength evaluation with the acceptable accuracy. It can be seen from this research that WFD could result in significantly reduction in the residual strength of stiffened panels.

Corrosion Strength Analysis of Casing in Offshore Thermal Recovery Wells

2019 ◽  
Vol 944 ◽  
pp. 956-964
Author(s):  
Jun Li ◽  
Xue Feng Song ◽  
Gong Hui Liu ◽  
Yan Xi ◽  
Wei Lian ◽  
...  
Keyword(s):  
Residual Strength ◽  
Thermal Recovery ◽  
Local Corrosion ◽  
Strength Analysis ◽  
Transient Temperature ◽  
Engineering Practice ◽  
Uniform Corrosion ◽  
Corrosion Morphology ◽  
Corrosion Depth ◽  
Temperature And Pressure

Corrosion is a common problem in offshore oil and gas wells, especially in thermal recovery wells, which will greatly affect the residual strength of casing strings. Field data show that the corrosion pattern of casing is mainly pitting, local corrosion and uniform corrosion, of which pitting is the most common. For this reason, based on the engineering practice of thermal recovery well casing corrosion, the dynamic changes of wellbore temperature and pressure during the gas production process of thermal recovery wells are considered, and the numerical model of casing corrosion under transient temperature and pressure coupling is established. The influence of corrosion morphology and corrosion depth on the residual strength of the casing is analyzed. The transient stress variation law of the corroded casing is studied. The results show that: (1) Under the same corrosion depth, both pitting and uniform corrosion will reduce the residual internal pressure and external extrusion strength of the casing string, and the degree of influence is similar. The effect of uniform corrosion on the residual tensile strength of the casing string is larger than pitting and local corrosion; (2) the residual strength of the casing decreases linearly with the increase of the corrosion depth of the casing; (3) the stress of the corrosion part of the casing shows a significant dynamic change, in the initial stage of steam injection, casing stress rises rapidly at the corrosion position, and then the rate at which the casing stress rises is slowed, which tends to cause fatigue damage to the casing. The research results have reference significance for the assessment of the service status of offshore thermal recovery well casings.

Analysis of the Contact Deformation of Tread Blocks

1992 ◽  
Vol 20 (4) ◽  
pp. 230-253 ◽  
Author(s):  
T. Akasaka ◽  
K. Kabe ◽  
M. Koishi ◽  
M. Kuwashima
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Deformation Behavior ◽  
Contact Deformation ◽  
The Finite Element Method ◽  
The Road ◽  
Loss Of Contact ◽  
Tread Rubber ◽  
Good Agreement ◽  
Rubber Block

Abstract The deformation behavior of a tire in contact with the roadway is complicated, in particular, under the traction and braking conditions. A tread rubber block in contact with the road undergoes compression and shearing forces. These forces may cause the loss of contact at the edges of the block. Theoretical analysis based on the energy method is presented on the contact deformation of a tread rubber block subjected to compressive and shearing forces. Experimental work and numerical calculation by means of the finite element method are conducted to verify the predicted results. Good agreement is obtained among these analytical, numerical, and experimental results.

Composite Solutions for Deck Catamarans

2018 ◽  
Vol 55 (1) ◽  
pp. 1-4
Author(s):  
Elena Felicia Beznea ◽  
Ionel Chirica ◽  
Adrian Presura ◽  
Ionel Iacob
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sandwich Structure ◽  
High Strength ◽  
Total Weight ◽  
External Loading ◽  
Strength Analysis ◽  
Allowable Stress ◽  
The Finite Element Method ◽  
Inland Navigation

The paper is treating the strength analysis of the main deck structure of an inland navigation catamaran for 30 passengers. The main deck should have high stiffness and high strength to resist to external loading and endure high stresses from combined bending and torsion loads. Different materials for sandwich structure of the deck have been analysed by using the Finite Element Method in order to determine the solution which accomplish better designing criteria regarding allowable stress and deformations and total weight.

scholarly journals Structural Damage Identification Based on Integrated Utilization of Inverse Finite Element Method and Pseudo-Excitation Approach

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 606
Author(s):  
Tengteng Li ◽  
Maosen Cao ◽  
Jianle Li ◽  
Lei Yang ◽  
Hao Xu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Structural Damage ◽  
Damage Identification ◽  
Displacement Measurement ◽  
Engineering Practice ◽  
Position Measurement ◽  
Inverse Finite Element Method ◽  
Pseudo Excitation ◽  
Element Method

The attempt to integrate the applications of conventional structural deformation reconstruction strategies and vibration-based damage identification methods is made in this study, where, more specifically, the inverse finite element method (iFEM) and pseudo-excitation approach (PE) are combined for the first time, to give rise to a novel structural health monitoring (SHM) framework showing various advantages, particularly in aspects of enhanced adaptability and robustness. As the key component of the method, the inverse finite element method (iFEM) enables precise reconstruction of vibration displacements based on measured dynamic strains, which, as compared to displacement measurement, is much more adaptable to existing on-board SHM systems in engineering practice. The PE, on the other hand, is applied subsequently, relying on the reconstructed displacements for the identification of structural damage. Delamination zones in a carbon fibre reinforced plastic (CFRP) laminate are identified using the developed method. As demonstrated by the damage detection results, the iFEM-PE method possesses apparently improved accuracy and significantly enhanced noise immunity compared to the original PE approach depending on displacement measurement. Extensive parametric study is conducted to discuss the influence of a variety of factors on the effectiveness and accuracy of damage identification, including the influence of damage size and position, measurement density, sensor layout, vibration frequency and noise level. It is found that different factors are highly correlated and thus should be considered comprehensively to achieve optimal detection results. The application of the iFEM-PE method is extended to better adapt to the structural operational state, where multiple groups of vibration responses within a wide frequency band are used. Hybrid data fusion is applied to process the damage index (DI) constructed based on the multiple responses, leading to detection results capable of indicating delamination positions precisely.

scholarly journals Special Issue “Applications of Finite Element Modeling for Mechanical and Mechatronic Systems”

2021 ◽  
Vol 11 (11) ◽  
pp. 5170
Author(s):  
Marek Krawczuk ◽  
Magdalena Palacz
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Engineering Practice ◽  
The Finite Element Method ◽  
Special Issue ◽  
Mechatronic Systems ◽  
Modeling And Analysis ◽  
Modern Engineering ◽  
Concise Description

Modern engineering practice requires advanced numerical modeling because, among other things, it reduces the costs associated with prototyping or predicting the occurrence of potentially dangerous situations during operation in certain defined conditions. Different methods have so far been used to implement the real structure into the numerical version. The most popular have been variations of the finite element method (FEM). The aim of this Special Issue has been to familiarize the reader with the latest applications of the FEM for the modeling and analysis of diverse mechanical problems. Authors are encouraged to provide a concise description of the specific application or a potential application of the Special Issue.

scholarly journals A strength analysis of conventional and sandwich plate deck using finite element method

2021 ◽  
Vol 1034 (1) ◽  
pp. 012026
Author(s):  
Abdi Ismail ◽  
Achmad Zubaydi ◽  
Bambang Piscesa ◽  
Ervan Panangian ◽  
Rizky Chandra Ariesta ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sandwich Plate ◽  
Strength Analysis ◽  
Element Method

Modified Swift Criteria for Residual Strength of Multiple Site Damage Structure

2009 ◽  
Vol 417-418 ◽  
pp. 881-884 ◽  
Author(s):  
Jian Yu Zhang ◽  
Rui Bao ◽  
Bin Jun Fei
Keyword(s):  
Residual Strength ◽  
Yield Criterion ◽  
Fatigue Cracks ◽  
Tensile Load ◽  
Maximum Load ◽  
Alloy Sheet ◽  
Multiple Cracks ◽  
Multiple Site ◽  
Multiple Site Damage ◽  
Aluminum Panels

As more aircrafts reach or exceed their design life, it is becoming very important to research multiple cracks damage, especially the multiple site damage (MSD) in order to re-evaluate their service life and damage tolerance/durability performance. The existing of MSD may remarkably reduce the residual strength of an aerospace structural component than those with a singe lead crack. This study investigated the residual strength of aluminum alloy sheet with MSD through three types of aluminum specimens test. Aluminum panels with bare collinear constant diameter holes were chosen as specimens. After some constant amplitude tension-tension load cycles, the MSD were found in these specimens since there were multiple fatigue cracks emanating from the saw cuts of holes. The residual strength was recorded as the maximum load when every specimen was subjected to monotonically increasing tensile load until failure occurred. In different failure prediction criteria that were often used in engineering in order to evaluate the accuracy of these criteria, Swift criterion (ligament yield) criterion got more accurate prediction results than other criteria. Although Swift criterion was more accurate than some other criteria, its error was still big for some specimens. Two modified approaches were proposed in order to get more accurate and appropriate failure criterion for MSD structure.

scholarly journals Residual Strength Analysis Method for Composite Laminates with Internal Defects Using a Quasi-Three-Dimensional Model.

1993 ◽  
Vol 59 (563) ◽  
pp. 1697-1701 ◽  
Author(s):  
Tsuyoshi Nishiwaki ◽  
Atsushi Yokoyama ◽  
Zen'ichiro Maekwa ◽  
Hiroyuki Hamada ◽  
Yoshinori Maekawa ◽  
...  
Keyword(s):  
Residual Strength ◽  
Composite Laminates ◽  
Three Dimensional ◽  
Strength Analysis ◽  
Analysis Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Internal Defects

Simulation and Optimization of Wedge-Shaped Ultrasonic Transducers Using Finite Element Method (FEM)

2013 ◽  
Vol 281 ◽  
pp. 112-115 ◽  
Author(s):  
Dan Jin ◽  
Zhao Hui Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Effect ◽  
Ultrasonic Transducers ◽  
Fe Model ◽  
Limited Size ◽  
Simulation And Optimization ◽  
Ultrasonic Flaw ◽  
Shape And Size ◽  
Good Agreement

Wedge-shaped transducers have been widely used in industry as probes for ultrasonic flowmeters or for ultrasonic flaw detectors. But by now, few studies have focused on the influence to the performance of the wedge-shaped transducers brought by their limited size. In this paper, the effect of the shape and size of wedge-shaped substrates on the whole transducer system is discussed and the shape and size of a transducer (0.5MHz) is optimized to eliminate the influence of the boundary effect by using a 2-D Finite Element (FE) model. Lastly, wedge-shaped transducers have been manufactured for experiment which shows a good agreement with the simulation.

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