Nonlinear Buckling Finite Element Analysis of Stiffened Steel Plates

2013 ◽  
Vol 699 ◽  
pp. 450-456 ◽  
Author(s):  
E. Gunay ◽  
C. Aygun ◽  
Y. O. Yıldız

In this paper, thin rectangular steel plates with stiffeners are examined under compressive loading. Consequently, nonlinear buckling finite element analysis (FEA) solutions are obtained by using ANSYS®. The local and global buckling patterns of stiffened steel plate geometries with simply supported boundary conditions are generated and critical buckling stresses are studied. Geometrically nonlinear buckling analyses are compared in order to evaluate the distributions of compressive stresses versus in-plane contractions and compressive stresses versus out-of plane deflections. Hence, it is concluded that there are critical load intervals. It is also observed that for critical loads, segments between stiffeners may switch from stable to unstable configurations under compressive stresses.

2014 ◽  
Vol 998-999 ◽  
pp. 530-533
Author(s):  
Yi Yin ◽  
Tao Tao Zhang ◽  
Xiao Dan Li

The ultimate bearing capacity of diagonally stiffened steel plates with different Span-depth ratio were analyzed by the finite element analysis software ANSYS. During the analysis, three groups of diagonally stiffened steel plates with different Span-depth ratio has been taken numerical investigations on static load, and obtained the stress distribution law of development and contrast characteristics of bearing capacity. Analysis shows components' yield and ultimate loads will be significantly improved with the decrease of Span-depth ratio. That means plates with small Span-depth ratio have better mechanical properties.


2021 ◽  
Vol 11 (13) ◽  
pp. 6094
Author(s):  
Hubdar Hussain ◽  
Xiangyu Gao ◽  
Anqi Shi

In this study, detailed finite element analysis was conducted to examine the seismic performance of square and circular hollow steel braces under axial cyclic loading. Finite element models of braces were constructed using ABAQUS finite element analysis (FEA) software and validated with experimental results from previous papers to expand the specimen’s matrix. The influences of cross-section shape, slenderness ratio, and width/diameter-to-thickness ratio on hysteretic behavior and compressive-tensile strength degradation were studied. Simulation results of parametric studies show that both square and circular hollow braces have a better cyclic performance with smaller slenderness and width/diameter-to-thickness ratios, and their compressive-tensile resistances ratio significantly decreases from cycle to cycle after the occurrence of the global buckling of braces.


2016 ◽  
Vol 41 (5) ◽  
pp. E149-E158 ◽  
Author(s):  
VF Wandscher ◽  
CD Bergoli ◽  
IF Limberger ◽  
TP Cenci ◽  
P Baldissara ◽  
...  

SUMMARY Objective: This article aims to present a fractographic analysis of an anterior tooth restored with a glass fiber post with parallel fiber arrangement, taking into account force vectors, finite element analysis, and scanning electron microscopy (SEM). Methods: A patient presented at the Faculty of Dentistry (Federal University of Santa Maria, Brazil) with an endodontically treated tooth (ETT), a lateral incisor that had a restorable fracture. The treatment was performed, and the fractured piece was analyzed using stereomicroscopy, SEM, and finite element analysis. Results: The absence of remaining coronal tooth structure might have been the main factor for the clinical failure. We observed different stresses actuating in an ETT restored with a fiber post as well as their relationship with the ultimate fracture. Tensile, compression, and shear stresses presented at different levels inside the restored tooth. Tensile and compressive stresses acted together and were at a maximum in the outer portions and a minimum in the inner portions. In contrast, shear stresses acted concomitantly with tensile and compressive stresses. Shear was higher in the inner portions (center of the post), and lower in the outer portions. This was confirmed by finite element analysis. The SEM analysis showed tensile and compression areas in the fiber post (exposed fibers=tensile areas=lingual surface; nonexposed fibers=compression areas=buccal surface) and shear areas inside the post (scallops and hackle lines). Stereomicroscopic analysis showed brown stains in the crown/root interface, indicating the presence of microleakage (tensile area=lingual surface). Conclusion: We concluded that glass fiber posts with parallel fibers (0°), when restoring anterior teeth, present a greater fracture potential by shear stress because parallel fibers are not mechanically resistant to support oblique occlusal loads. Factors such as the presence of remaining coronal tooth structure and occlusal stability assist in the biomechanical equilibrium of stresses that act upon anterior teeth.


2018 ◽  
Vol 285 (1887) ◽  
pp. 20181473 ◽  
Author(s):  
Charlotte A. Brassey ◽  
James D. Gardiner ◽  
Andrew C. Kitchener

The baculum (os penis) is a mineralized bone within the glans of the mammalian penis and is one of the most morphologically diverse structures in the mammal skeleton. Recent experimental work provides compelling evidence for sexual selection shaping the baculum, yet the functional mechanism by which this occurs remains unknown. Previous studies have tested biomechanical hypotheses for the role of the baculum based on simple metrics such as length and diameter, ignoring the wealth of additional shape complexity present. For the first time, to our knowledge, we apply a computational simulation approach (finite-element analysis; FEA) to quantify the three-dimensional biomechanical performance of carnivoran bacula (n= 74) based upon high-resolution micro-computed tomography scans. We find a marginally significant positive correlation between sexual size dimorphism and baculum stress under compressive loading, counter to the ‘vaginal friction’ hypothesis of bacula becoming more robust to overcome resistance during initial intromission. However, a highly significant negative relationship exists between intromission duration and baculum stress under dorsoventral bending. Furthermore, additional FEA simulations confirm that the presence of a ventral groove would reduce deformation of the urethra. We take this as evidence in support of the ‘prolonged intromission’ hypothesis, suggesting the carnivoran baculum has evolved in response to pressures on the duration of copulation and protection of the urethra.


Author(s):  
Samuel J. Miller ◽  
Hakan Ozaltun

This article analyzes dimensional changes due to irradiation of monolithic plate-type nuclear fuel and compares results with finite element analysis of the plates during fabrication and irradiation. Monolithic fuel plates tested in the Advanced Test Reactor (ATR) at Idaho National Lab (INL) are being used to benchmark the performance of proposed fuel for several high power research reactors. Post-irradiation metallographic images of plates sectioned at the mid-plane were analyzed to determine dimensional changes of the fuel and the cladding response. A constitutive model of the fabrication process and irradiation behavior of the tested plates was developed using the general purpose commercial finite element analysis package, ABAQUS. Using calculated burn-up profiles of irradiated plates to model the power distribution and including irradiation behaviors such as swelling and irradiation enhanced creep, model simulations allow analysis of plate parameters that are either impossible or infeasible in an experimental setting. The development and progression of fabrication induced stress concentrations at the plate edges was of primary interest, as these locations have a unique stress profile during irradiation. Additionally, comparison between 2D and 3D models was performed to optimize analysis methodology. In particular, the ability of 2D and 3D models to account for out of plane stresses which result in 3-dimensional creep behavior that is a product of these components. Results show that assumptions made in 2D models for the out-of-plane stresses and strains cannot capture the 3-dimensional physics accurately and thus 2D approximations are not representative. Stress-strain fields are dependent on plate geometry and irradiation conditions, thus, if stress based criteria is used to predict plate behavior (as opposed to material impurities, fine micro-structural defects, or sharp power gradients), unique 3D finite element formulation for each plate is required.


2008 ◽  
Vol 392-394 ◽  
pp. 980-984 ◽  
Author(s):  
Y. Sha ◽  
Hui Tang ◽  
Jia Zhen Zhang

In this paper, a detailed elastic-plastic finite element analysis of the effect of the compressive loading on crack tip plasticity is studied based on the material’s kinematic hardening model. Five centre-cracked panel specimens with different crack lengths are analyzed. The analysis shows that in a tension-compression loading the maximum spread of the crack tip reverse plastic zone increases with the increase of the compressive stress and the near crack tip opening displacement decreases with the increase of the compressive stress at the same nominal stress intensity factor. The applied compressive stress is the main factor controlling the near crack tip parameters.


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