scholarly journals A Parameter Sensitivity Analysis of the Effect of Rebar Corrosion on the Stress Field in the Surrounding Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Fangyuan Li ◽  
Wenya Ye
Keyword(s):  
Finite Element Method ◽  
Stress Field ◽  
Prestressed Concrete ◽  
Radial Displacement ◽  
Protective Layer ◽  
Fem Analysis ◽  
The Finite Element Method ◽  
Parameter Sensitivity Analysis ◽  
Ordinary Concrete ◽  
Rebar Corrosion

Rebar corrosion results in a change in the stress field in the surrounding concrete, which in turn accelerates the deterioration of the concrete structure. In addition to the protective layer, the compressive stress under which concrete is prestressed also affects the effect of corrosion-induced rebar expansion on the stress field in the concrete. The present study simulates the effect of corrosion-induced rebar expansion on the stress field in the concrete using the finite element method (FEM) by applying a virtual radial displacement to the product of corrosion-induced rebar expansion. Based on an analysis of the effect of multiple rebars on the stress field in ordinary concrete, stress distribution in the protective layer of the concrete is determined. Afterward, the locations where there is damage to the surface concrete caused by rebar corrosion are determined. After verifying the feasibility of the FEM analysis, the effect of corrosion-induced ordinary rebar expansion in a typical prestressed concrete segment is determined by analyzing the characteristics of corrosion-induced rebar expansion occurring in various prestressed concrete specimens.

Effect Review of the Strengthening Technique by Use of the External Prestressing

2011 ◽  
Vol 121-126 ◽  
pp. 3258-3262
Author(s):  
Long Sheng Bao ◽  
Dan Yang ◽  
Ling Yu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
Prestressed Concrete ◽  
Measured Data ◽  
The Finite Element Method ◽  
Construction Monitoring ◽  
External Prestressing ◽  
Monitoring Result ◽  
Strengthening Technique

The grand bridge of Fu Feng is prestressed concrete cross-section continuous girder, which is reinforced with external prestressing. Construction monitoring is based on the measured data, and using the finite element method to calculate, it need to analyze the control of the stress and deflection in the construction to ensure to make the construction could be completed on schedule and to reach an ideal type. The field monitoring result indicates that the type of bridge did improve and reach the requirement of design after reinforcement.

Modified Coronal Incision: Distribution of Stress in the Scalp and Cranium

1993 ◽  
Vol 30 (4) ◽  
pp. 382-386
Author(s):  
Sadanori Akita ◽  
Akiyoshi Hirano
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Distribution ◽  
Fem Analysis ◽  
Craniofacial Surgery ◽  
The Finite Element Method ◽  
Modified Method ◽  
Distribution Of Stress ◽  
Scalp Incision ◽  
Coronal Incision

Coronal incision or bitemporal incision is useful for wider visualization in craniofacial surgery. In volume-expanding surgery such as fronto-orbital advancement, however, the incisional scar in the temporal scalp is often undesirably wide and conspicuous. We modified the coronal incision to avoid the widened scar. Further, we analyzed the resulting stress distribution using the finite element method (FEM) to determine whether or not the modification we adapted was effective. The modified method of coronal scalp incision that we used for craniofacial surgery is practical and technically easy. FEM analysis showed that our method was effective in terms of mechanical strength. The simulated surgical craft model is presented and is concluded to be beneficial for further analysis in craniofacial surgery.

scholarly journals An Improved Equation for Predicting Compressive Stress in Posttensioned Anchorage Zone

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Young-Ha Park ◽  
Moon-Young Kim ◽  
Jong-Myen Park ◽  
Se-Jin Jeon
Keyword(s):  
Finite Element Method ◽  
Compressive Stress ◽  
Prestressed Concrete ◽  
Approximate Equation ◽  
The Finite Element Method ◽  
Concrete Member ◽  
Design Specifications ◽  
Compressive Stresses ◽  
Aashto Lrfd ◽  
Accurate Stress

Validity of the approximate equation for predicting compressive stress in the posttensioned anchorage zone presented in the AASHTO LRFD Bridge Design Specifications was investigated in this study. Numerical analysis based on the finite element method (FEM) and theoretical analysis showed that the AASHTO formula gives relatively accurate stress values when the effect of duct holes is neglected. However, it was found that the formula can significantly overestimate the stresses in the actual prestressed concrete member with spaces occupied by ducts. Therefore, an improved equation was proposed for the existing AASHTO equation to consider the effect of the duct holes on the stress distribution. This resulted in relatively accurate prediction of the distribution and magnitude of the compressive stresses even with the presence of the duct holes. The proposed equation was also validated by comparing with the stresses measured in the test of a posttensioned full-scale specimen. This study is expected to contribute to the design of the anchorage zone in prestressed concrete structures by suggesting a more reasonable way to assess the appropriateness of anchorage devices.

scholarly journals Improved Expression for Estimation of Leakage Inductance in E Core Transformer Using Energy Method

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Sivananda Reddy Thondapu ◽  
Mangesh B. Borage ◽  
Yashwant D. Wanmode ◽  
Purushottam Shrivastava
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Energy Method ◽  
Fem Analysis ◽  
Field Pattern ◽  
The Finite Element Method ◽  
Leakage Inductance ◽  
Accurate Expression ◽  
Element Method

This paper proposes a simpler and more accurate expression for estimation of leakage inductance in E core transformer, which is the most widely used transformer structure. The derived expression for leakage inductance accounts for the flux extending into air. The finite element method (FEM) analysis is made on the secondary shorted transformer to observe the H-field pattern. The results obtained from FEM analysis are used for approximating the field that is extending into air to derive an expression for leakage inductance. This expression is experimentally validated on prototype transformers of different core dimensions.

scholarly journals Voids Nucleation at Inclusions of Various Shapes in Front of the Crack in Plane Strain

2016 ◽  
Vol 61 (3) ◽  
pp. 1587-1592 ◽  
Author(s):  
A. Neimitz ◽  
U. Janus
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Distribution ◽  
Stress Field ◽  
Plane Strain ◽  
Crack Front ◽  
The Finite Element Method ◽  
Element Method

Abstract An analysis is presented of the stress field in and around inclusions of various shapes. Results were obtained by the finite element method. Inclusions were located within elementary cells located at the centre of the specimen next to the crack front. The influence of an in-plane constraint on the stress distribution was tested.

Study of the Torsional Effect of a Rectangular Quartz Disc

2011 ◽  
Vol 474-476 ◽  
pp. 2286-2289
Author(s):  
Chang Yin Gao ◽  
Wan Quan Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Field ◽  
Theoretical Analysis ◽  
Anisotropic Elasticity ◽  
Electromagnetic Theory ◽  
The Finite Element Method ◽  
Piezoelectric Body ◽  
Quartz Disc ◽  
Piezoelectric Wafers

The torsional effect of a rectangular piezoelectric quartz is studied in the article. Using the anisotropic elasticity and Maxwell electromagnetic theory, the stress field and electrostatic field is founded, and then by the Finite Element Method the distribution of the electric field in the piezoelectric body is obtained. Based on theoretical analysis of the bound charge distribution, the measuring electrodes are effectively disposed on the surfaces of the piezoelectric wafers. The theoretical and experimental results show that the measurement charge is linear with the torque. The research will provide the basis for the torque measuring technique.

Numerical Analysis of a Crack Emanating from Semicircular Notch with Connection to a Pre-Existing Crack

2012 ◽  
Vol 428 ◽  
pp. 114-120
Author(s):  
Mohamed Sahnoun ◽  
Djamel Ouinas
Keyword(s):  
Finite Element Method ◽  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Numerical Analysis ◽  
Stress Concentration ◽  
Intensity Factor ◽  
Stress Field ◽  
The Finite Element Method ◽  
Stress Concentrations

The real structures are of complex geometrical forms containing numerous zones of stress concentrations. These sites are characterized by weak sections due to the presence of notches which are the main causes of cracks initiation. The knowledge of the distribution of the stress field in the neighborhood of a notch is of an extreme importance for the analysis of the variation of the stress concentration factor with respect to the geometry of the notch. In this paper, the finite element method is used to study the effect of the existence of a microcrack on the behaviour of a notched structure. Then the behaviour of a crack emanating from the notch with the presence of the pre-existing crack is also investigated. It requires estimating the stress intensity factor at the crack tip, the length of the crack, the notch diameter and the angle between its bisecting line and the crack direction.

scholarly journals Optimized Design of an ECAP Die Using the Finite Element Method for Obtaining Nanostructured Materials

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Patricia Ponce-Peña ◽  
Edgar López-Chipres ◽  
Edgar García-Sánchez ◽  
Miguel Angel Escobedo-Bretado ◽  
Brenda Xiomara Ochoa-Salazar ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Finite Element ◽  
Tensile Strain ◽  
Fem Analysis ◽  
Optimized Design ◽  
The Finite Element Method ◽  
Angular Pressing ◽  
Cracking Tendency ◽  
Element Method

An alloy type A16060 was exposed to severe plastic deformation to study its reaction using the finite element method (FEM). To perform this, six different configurations were used in the design of the die’s channel for ECAP (equal channel angular pressing) to obtain nanostructure materials and to optimize the process. Thanks to simulation performed with FEM, it is possible to study the homogeneity in the deformation due to the variation of conditions affecting directly the material being processed using the ECAP technique, such as the friction coefficient, extrusion speed, and mainly the die’s channel geometry being utilized in the ECAP process. Due to the tensile strain area being located mainly in the upper part of the deformed test cylinder (plastic deformation area) which increases the fracture and cracking tendency preventing the processing through ECAP the die being utilized was modified to eliminate the tensile strain area favoring the appearance of compressive stress which reduces the cracking tendency and the fracture of the sample being processed. The FEM analysis demonstrated that the strain state changed significantly from tension to compression when the modified die was used, facilitating the processing of the piece by ECAP.

Comparison of Performance between Concentrated and Rhombic Windings for a Slotless Brushless DC Motor

2011 ◽  
Vol 130-134 ◽  
pp. 2832-2835
Author(s):  
Chang Chou Hwang ◽  
Ping Lun Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fem Analysis ◽  
Dc Motor ◽  
Brushless Dc Motor ◽  
The Finite Element Method ◽  
Brushless Dc ◽  
Three Phase ◽  
Element Method

This paper presents and compares the performance of a two-pole, three-phase slotless brushless DC motor with two types of winding configuration: concentrated and rhombic windings. Application of the finite element method (FEM) analysis to their performance calculations is performed.

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