scholarly journals Analysis of the Main Aspects Affecting Bonding in Stainless Steel Rebars Embedded in a Hydraulic Medium

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 786
Author(s):  
Fernando Ancio ◽  
Esperanza Rodriguez-Mayorga ◽  
Beatriz Hortigon
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Boundary Conditions ◽  
Masonry Structures ◽  
Finite Element Analyses ◽  
Pull Out ◽  
Mathematical Expressions ◽  
Special Circumstances ◽  
Steel Rebars

The use of stainless steel rebars to reinforce masonry structures has become established as an eminently efficient methodology. From among the numerous techniques available, bed-joint structural repointing and superficial reinforcement with rebars or meshes attached to surfaces have become widespread, thanks to the excellent results they have produced in recent decades. Both techniques imply the use of diameters less than 6 mm and thin coverings. This article deals with the characterization of the bonding behavior of the rebar under these special circumstances. To this end, several finite element analyses have been carried out to identify the possible relationships between pull-out forces in various situations. These models allow certain conclusions to be drawn regarding the influence of the thickness of covering, boundary conditions, and geometrical aspects of the rebars in bonding. Certain mathematical expressions that relate the various conclusions from this research are finally laid out.

scholarly journals Analysis of Monolithic and Sandwich Panels Subjected To Non-Uniform Thickness-Wise Boundary Conditions

2016 ◽  
Vol 5 (1) ◽  
pp. 232-249
Author(s):  
Riccardo Vescovini ◽  
Lorenzo Dozio
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Sandwich Plate ◽  
Sandwich Plates ◽  
Vibration Frequencies ◽  
Thickness Direction ◽  
Finite Element Analyses ◽  
Uniform Thickness ◽  
Bending Problems ◽  
High Degree

Abstract The analysis of monolithic and sandwich plates is illustrated for those cases where the boundary conditions are not uniform along the thickness direction, and run at a given position along the thickness direction. For instance, a sandwich plate constrained at the bottom or top face can be considered. The approach relies upon a sublaminate formulation,which is applied here in the context of a Ritz-based approach. Due to the possibility of dividing the structure into smaller portions, viz. the sublaminates, the constraints can be applied at any given location, providing a high degree of flexibility in modeling the boundary conditions. Penalty functions and Lagrange multipliers are introduced for this scope. Results are presented for free-vibration and bending problems. The close matching with highly refined finite element analyses reveals the accuracy of the proposed formulation in determining the vibration frequencies, as well as the internal stress distribution. Reference results are provided for future benchmarking purposes.

scholarly journals Finite Element Analyses of Cold‐formed Stainless Steel Beams Subject to Shear

ce/papers ◽  
2019 ◽  
Vol 3 (3-4) ◽  
pp. 931-936
Author(s):  
Madhushan Dissanayake ◽  
Keerthan Poologanathan ◽  
Shanmuganathan Gunalan ◽  
Konstantinos Daniel Tsavdaridis ◽  
Brabha Nagaratnam
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Steel Beams ◽  
Finite Element Analyses

Evaluation of Residual Stresses in Small Diameter Stainless Steel Pipe Welds by Two-Dimensional and Three-Dimensional Finite Element Analyses

2014 ◽  
Author(s):  
Francis H. Ku ◽  
Trevor G. Hicks ◽  
William R. Mabe ◽  
Jason R. Miller
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Steel Pipe ◽  
3D Analysis ◽  
Two Dimensional ◽  
Finite Element Analyses ◽  
Stainless Steel Pipe

Two-dimensional (2D) and three-dimensional (3D) weld-induced residual stress finite element analyses have been performed for 2-inch Schedule 80 Type-304 stainless steel pipe sections joined by a multi-layer segmented-bead pipe weld. The analyses investigate the similarities and differences between the two modeling approaches in terms of residual stresses and axial shrinkage induced by the pipe weld. The 2D analyses are of axisymmetric behavior and evaluate two different pipe end constraints, namely fixed-fixed and fixed-free, while the 3D analysis approximates the non-axisymmetric segmented welding expected in production, with fixed-free pipe end constraints. Based on the results presented, the following conclusions can be drawn. The welding temperature contour results between the 2D and 3D analyses are very similar. Only the 3D analysis is capable of simulating the non-axisymmetric behavior of the segmented welding technique. The 2D analyses yield similar hoop residual stresses to the 3D analysis, and closely capture the maximum and minimum ID surface hoop residual stresses from the 3D analysis. The primary difference in ID surface residual stresses between the 2D fixed-fixed and 2D fixed-free constraints cases is the higher tensile axial stresses in the pipe outside of the weld region. The 2D analyses under-predict the maximum axial residual stress compared to the 3D analysis. The 2D ID surface residual stress results tend to bound the averaged 3D results. 2D axisymmetric modeling tends to significantly under-predict weld shrinkage. Axial weld shrinkage from 3D modeling is of the same magnitude as values measured in the laboratory on a prototypic mockup.

scholarly journals Finite element modeling of nanoindentation on an elastic-plastic microsphere

2020 ◽  
Author(s):  
Jialian Chen ◽  
Hongzhou Li
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Computational Study ◽  
Theoretical Method ◽  
Finite Element Analyses ◽  
Structured Materials ◽  
Elastic Plastic ◽  
Element Simulation ◽  
Insight Into

Abstract The understanding of the mechanical indentation on a curved specimen (e.g., microspheres and microfibers) is of paramount importance in the characterization of curved micro-structured materials, but there has been no reliable theoretical method to evaluate the mechanical behavior of nanoindentation on a microsphere. This article reports a computational study on the instrumented nanoindentation of elastic-plastic microsphere materials via finite element simulation. The finite element analyses indicate that all loading curves are parabolic curves and the loading curve for different materials can be calculated from one single indentation. The results demonstrate that the Oliver-Pharr formula is unsuitable for calculating the elastic modulus of nanoindentation involving cured surfaces. The surface of the test specimen of a microsphere requires prepolishing to achieve accurate results of indentation on a micro-spherical material. This study provides new insight into the establishment of nanoindentation models that can effectively be used to simulate the mechanical behavior of a microsphere.

Prediction of Fatigue Crack Initiation and Growth During Thermal Cycling

2015 ◽  
Author(s):  
Guiyi Wu ◽  
David Smith ◽  
David Tanner
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Crack Initiation ◽  
Thermal Cycling ◽  
Dwell Time ◽  
Thermal Loading ◽  
Fatigue Cracks ◽  
Fatigue Crack Initiation ◽  
Stress And Strain ◽  
Finite Element Analyses

Conventional approaches to assess fatigue under combined thermal and mechanical loading often utilize a fatigue design curve. In this paper models based on the physics and mechanics for the initiation and growth of fatigue cracks in stainless steel are first explained. The models are based on experimental evidence gathered for the initiation and growth of small cracks created during strain controlled laboratory tests. This evidence is then linked with data for the growth of large fatigue cracks in stainless steel. In the paper these models are coupled with finite element analyses to explore the fatigue initiation and growth of cracks in stainless steel pipes subjected to thermal cycling. It is assumed that the material behaviour is elastic-perfectly plastic, rate independent and fatigue occurs in air. The stress and strain fields for pipes subjected to a range of thermal loading conditions are explored. The fields are shown to be sensitive to parameters such as the Biot and Fourier numbers that include pipe dimensions, physical properties, dwell time and thermal conditions. Of particular interest is the temperature range and dwell time during thermal loading. Finite element analyses are then used to determine the stress and strain ranges created by thermal loading and these ranges are used in the crack initiation and growth models to estimate fatigue life.

Identifying Elastic Properties of Isotropic Materials by Finite Element Analyses and Vibration Data

2007 ◽  
Vol 345-346 ◽  
pp. 1327-1330 ◽  
Author(s):  
Marco Alfano ◽  
Leonardo Pagnotta ◽  
Giambattista Stigliano
Keyword(s):  
Finite Element ◽  
Error Function ◽  
Finite Element Analyses ◽  
Vibration Testing ◽  
Isotropic Materials ◽  
Vibration Data ◽  
The Difference ◽  
Optimizing Algorithm ◽  
Non Destructive

The use of non destructive techniques for the elastic characterization of isotropic materials is continuously increasing and those based on the modal vibration testing of plate-like specimens is very widespread. In the present paper, an optimized search procedure is proposed which allows the material constants of isotropic plates to be non-destructively identified from vibration testing data and using finite element analyses. The identification process is performed by an optimizing algorithm in which the error function to be minimized depends on the difference between the natural frequencies obtained by finite element analyses and the measured ones. In order to verify the proposed identification procedure a comparison with the results reported in literature has been made.

Geometrical and Welding Conditions on Through-Thickness Residual Stress in Primary Piping of Girth Welded Joints

2008 ◽  
Vol 580-582 ◽  
pp. 573-576 ◽  
Author(s):  
Jinya Katsuyama ◽  
Masahito Mochizuki ◽  
Hiroaki Mori ◽  
W. Asano ◽  
Gyu Baek An ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Stress Corrosion Cracking ◽  
Welded Joints ◽  
Three Dimensional ◽  
Finite Element Analyses ◽  
Welding Zone ◽  
Butt Welding ◽  
Welding Joints

Recently, stress corrosion cracking (SCC) of primary piping of stainless steel has been observed. SCC is considered to initiate and progress at near the welding zone in butt-welded pipes, because of the tensile residual stress introduced by welding. In present work, three-dimensional and axisymmetric thermo-elastic-plastic finite element analyses have been carried out, in order to clarify the effect of geometrical and welding conditions on through-thickness residual stress. In particular, butt-welding joints of SUS316L pipes have been examined. The residual stress was simulated by three-dimensional and axisymmetric models and the results were compared and discussed in detail.

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