scholarly journals Numerical Investigation on Stress Concentration of Tension Steel Bars with One or Two Corrosion Pits

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jian Hou ◽  
Li Song
Keyword(s):  
Stress Concentration ◽  
Crack Nucleation ◽  
Three Dimensional ◽  
Relative Depth ◽  
Fatigue Crack Nucleation ◽  
Rc Structures ◽  
Steel Bars ◽  
Corrosion Pits ◽  
Tension Loading ◽  
Potential Origin

Pitting corrosion has been observed in steel bars of existing reinforced concrete (RC) structures in different erosion environments and has been identified as a potential origin for fatigue crack nucleation. In the present study, under uniaxial tension loading, stress distribution in the steel bars with one or two semiellipsoidal corrosion pits has systematically been investigated by conducting a series of three-dimensional semiellipsoidal pitted models. Based on the finite element analyses, it is shown that stress concentration factor (SCF) increases linearly with increasing pit aspect ratio (a/b) and increases nonlinearly with increasing pit relative depth (a/R) for single corrosion pit problem. For double corrosion pits problem, the SCF decreases nonlinearly with increasing angle of two transverse pits (θ). The interaction of two longitudinal pits can be ignored in the calculation of SCF even if the distance of two pits (d) is very small.

Three-dimensional tensile stress concentration in countersunk rivet holes

2007 ◽  
Vol 111 (1126) ◽  
pp. 777-786 ◽  
Author(s):  
A. Bhargava ◽  
K. N. Shivakumar
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Tensile Stress ◽  
Three Dimensional ◽  
Design Equation ◽  
Finite Element Stress Analysis ◽  
Wide Range ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Tension Loading

Abstract A detailed and accurate three-dimensional finite element stress analysis was conducted on countersunk rivet holes in a plate subjected to tension loading. The analysis included a wide range of countersunk depths, plate thicknesses, countersunk angles and plate widths. The study confirmed some of the previous results, addressed their differences, provided many new results, and investigated countersunk angle and width effects. Using the detailed FE results and the limiting conditions, a design equation for stress concentration was developed and verified.

scholarly journals Numerical analysis of axial compressive behavior of RC short columns subjected to non-uniform fire: A meso-scale study

2021 ◽  
Vol 272 ◽  
pp. 02028
Author(s):  
Xiaoya Li ◽  
Renbo Zhang ◽  
Liu Jin ◽  
Xiuli Du
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Three Dimensional ◽  
Simulation Method ◽  
Rc Structures ◽  
Compression Performance ◽  
Short Columns ◽  
Steel Bars ◽  
Meso Scale

The bearing capacity and durability of reinforced concrete (RC) structures can be affected by fire. In this study, a three-dimensional (3D) meso-scale simulation model for RC short column subjected to axial compression after exposure to fire was established. The degradation effect of mechanical properties of steel bars and concrete materials after high temperature was taken into account. The bond-slip behavior between longitudinal steel bars and concrete was also considered in the model. Based on the present simulation method, the failure mode and failure mechanism of the RC short columns were investigated. Moreover, the effects of fire scenario and fire duration on the axial compression performance of RC short columns were further investigated. It is found that the meso-scale numerical model can effectively simulate the mechanical behavior of RC short columns under axial load. Moreover, with the increase of fired surfaces and fire duration, the peak bearing capacity, axial compression stiffness and ductility decrease. The mechanical properties of short columns decrease more quickly under non-uniform fire. By comparing the theoretical value with the numerical simulation value of Nut/Nu, it is found that the theoretical value is conservative.

Different Failure Styles for Aluminum-Alloy Strip with Two Holes under Cyclic Tensile Loading

2011 ◽  
Vol 337 ◽  
pp. 660-664
Author(s):  
Fang Wen Wang ◽  
Hong Zuo ◽  
Yi Wen
Keyword(s):  
Experimental Investigation ◽  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Stress Concentration ◽  
Crack Nucleation ◽  
Tensile Loading ◽  
Alloy Strip ◽  
Fatigue Crack Nucleation ◽  
Center Region

This paper reports seven failure styles found in our experimental investigation for the failure between two neighbor holes located at different angle in an Aluminum-Alloy strip under cycle tensile loadings. In some cases, unlike expected, the initial fatigue crack is found not to nucleate at the center region between the two holes, where the stress concentration is larger than other region. In fact, the initial fatigue crack always nucleates at the outside rim of two holes far apart from the center region. The coalescence between the two holes always occurs far after the initial fatigue crack nucleation.

Fatigue Crack Nucleation and Growth Mechanisms for Ti6Al4V in Different Environments

2012 ◽  
Vol 525-526 ◽  
pp. 505-508 ◽  
Author(s):  
Sergio Baragetti ◽  
Cristian Foglia ◽  
Riccardo Gerosa
Keyword(s):  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Crack Nucleation ◽  
Fatigue Tests ◽  
Growth Mechanisms ◽  
Test Environment ◽  
Fatigue Crack Nucleation ◽  
Fracture Surfaces ◽  
Surface Morphologies

In this work fracture surfaces of Ti-6Al-4V flat samples subjected to fatigue tests were examined by means of a scanning electron microscope. SEM analyses allowed to observe in detail the morphology of the fracture surfaces, in order to identify the crack nucleation zones and the crack growth mechanisms accurately. The surface morphologies were examined in order to compare the alloy behavior, considering different test environments and stress concentration factor values (Kt). The analyses resulted in the observation of different corrosion fatigue micro-mechanisms related to the stress concentration factor and to the test environment.

Reduction of Free-Edge Stress Concentration

1985 ◽  
Vol 52 (4) ◽  
pp. 801-805 ◽  
Author(s):  
P. R. Heyliger ◽  
J. N. Reddy
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Free Edge ◽  
Shear Stresses ◽  
Normal Stresses ◽  
Interlaminar Shear ◽  
Three Dimensional Elasticity

A quasi-three dimensional elasticity formulation and associated finite element model for the stress analysis of symmetric laminates with free-edge cap reinforcement are described. Numerical results are presented to show the effect of the reinforcement on the reduction of free-edge stresses. It is observed that the interlaminar normal stresses are reduced considerably more than the interlaminar shear stresses due to the free-edge reinforcement.

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