Analysis of Stress Distribution of Externally Pre-Stressed Beams under Transverse Loads

2012 ◽  
Vol 166-169 ◽  
pp. 3065-3070
Author(s):  
Peng Zhang ◽  
Dan Shen ◽  
Shi Rong Li
Keyword(s):  
Mechanical Properties ◽  
Stress Distribution ◽  
Normal Stress ◽  
Cross Section ◽  
Beam Theory ◽  
Reinforcing Steel ◽  
Analytical Formulation ◽  
Simply Supported ◽  
Transverse Loads ◽  
Steel Bars

The size, the position and the arrangement of external restraint will significantly affect the mechanical properties of the structures with the external restraint. Based on classical beam theory, the stress distribution of a simply supported beam with externally reinforcing steel bars under transverse loads is analyzed in this presentation. By assuming that the stresses in both the beam and the external constrains are less than their proportional limits, an analytical formulation of normal stress in the cross section of the beam was derived by considering two cases that the externally reinforcing steel bars are pre-stressed and are not pre-stressed. Influences of the parameters of the stiffness and the position of the externally reinforcing steel bars on the stress of the beam are discussed.

scholarly journals Experimental Investigation into Corrosion Effect on Mechanical Properties of High Strength Steel Bars under Dynamic Loadings

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hui Chen ◽  
Jinjin Zhang ◽  
Jin Yang ◽  
Feilong Ye
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Dynamic Loading ◽  
High Strength Steel ◽  
High Strength ◽  
Tensile Tests ◽  
Reinforcing Steel ◽  
Test Results ◽  
Cross Sectional ◽  
Steel Bars

The tensile behaviors of corroded steel bars are important in the capacity evaluation of corroded reinforced concrete structures. The present paper studies the mechanical behavior of the corroded high strength reinforcing steel bars under static and dynamic loading. High strength reinforcing steel bars were corroded by using accelerated corrosion methods and the tensile tests were carried out under different strain rates. The results showed that the mechanical properties of corroded high strength steel bars were strain rate dependent, and the strain rate effect decreased with the increase of corrosion degree. The decreased nominal yield and ultimate strengths were mainly caused by the reduction of cross-sectional areas, and the decreased ultimate deformation and the shortened yield plateau resulted from the intensified stress concentration at the nonuniform reduction. Based on the test results, reduction factors were proposed to relate the tensile behaviors with the corrosion degree and strain rate for corroded bars. A modified Johnson-Cook strength model of corroded high strength steel bars under dynamic loading was proposed by taking into account the influence of corrosion degree. Comparison between the model and test results showed that proposed model properly describes the dynamic response of the corroded high strength rebars.

Analysis of Deep Beams

1951 ◽  
Vol 18 (2) ◽  
pp. 163-172
Author(s):  
H. D. Conway ◽  
L. Chow ◽  
G. W. Morgan
Keyword(s):  
Exact Solution ◽  
Approximate Solution ◽  
Stress Distribution ◽  
Finite Difference ◽  
Boundary Conditions ◽  
Normal Stress ◽  
Stress Function ◽  
Beam Theory ◽  
Deep Beam ◽  
Stress Functions

Abstract This paper presents a method of analyzing the stress distribution in a deep beam of finite length by superimposing two stress functions. The first stress function is chosen in the form of a trigonometric series which satisfies all but one of the boundary conditions—that of zero normal stress on the ends of the beam. The principle of least work is then used to obtain a second stress function giving the distribution of normal stress on the ends which is left by the first stress function. By superimposing the two solutions, all the boundary conditions are satisfied. Two particular cases of a given type of loading are solved in this way to investigate the stresses in a deep beam and their deviation from the ordinary beam theory. In addition, an approximate solution by the numerical method of finite difference is worked out for one of the two cases. Results from the two methods are compared and discussed. A method of obtaining an exact solution to the problem is given in an Appendix.

Determination of Some Mechanical Properties of Welded Reinforcing Steel with Self-Shielded Wires by Vibration Tests

2014 ◽  
Vol 1029 ◽  
pp. 206-211 ◽  
Author(s):  
Liviu Bereteu ◽  
Mircea Burcă ◽  
Raul Moisa ◽  
Dorin Simoiu ◽  
Gheorghe Drăgănescu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welding Process ◽  
Steel Reinforcement ◽  
Reinforcing Steel ◽  
Coated Electrode ◽  
Major Disadvantage ◽  
Steel Bars ◽  
Vibration Tests ◽  
The Cost

Reinforced concrete is a material formed by pouring concrete over reinforcement steel bars and wires and sometimes by a polymer that turns by drying in a hard and rigid composite. Welding of steel reinforcement concrete is a relatively difficult operation and with a large amount of work, given by the large number of welds that are needed and when this work is make in site conditions. The most common method of steel reinforcement welding is manual welding with coated electrode. The major disadvantage of this process is low productivity in welding effects on execution time, and the cost of welding. An alternative to manual welding with coated electrode for steel reinforcement welding on site is the welding process with self-shielded tubular wires.The aim of this paper is to determine the mechanical properties of welded reinforcing steel PC 52 with self-shielded wires, using a vibroacustic technique. To validate this method, the results obtained by vibroacoustic signal processing are compared with those determined by the tensile stresses of the same samples.

scholarly journals Essential Mechanical Properties of Structural Steels for Steel Reinforced Buildings in the Earthquake Sensitive Areas

2011 ◽  
Vol 4 (1) ◽  
pp. 51 ◽  
Author(s):  
M. A. Islam
Keyword(s):  
Mechanical Properties ◽  
Structural Steel ◽  
Fatigue Loading ◽  
Structural Steels ◽  
Reinforcing Steel ◽  
High Rise ◽  
Steel Bar ◽  
Steel Bars ◽  
Cyclic Type ◽  
Earthquake Effects

During earthquake, the ground along with its various natural and manmade structures experiences shaking of various intensities and frequencies depending on the nature of the earthquake. The loading activities caused by earthquakes on various structures are very much cyclic type, which is popularly known as fatigue loading. On the other hand, for modern high-rise buildings a large volume of steel bar is used to reinforce the concrete because of the pioneer role of steel bars embedded inside the concrete for safety of the buildings. In this study various mechanical properties of reinforcing steel bars that are essential to counter balance the earthquake effects have been identified first. At the same time these essential mechanical properties have been defined and studied for most commonly used reinforcing steel bars. For doing this, both the conventional and advanced structural steels were selected. The mechanical properties and fatigue behaviours of these steels have been presented and discussed in this paper.  Keywords: Earthquake; High-rise buildings; Reinforcing steel bars; Conventional structural steel; Advanced structural steel.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7069 J. Sci. Res. 4 (1), 51-63 (2012)

scholarly journals Experimental study on LBL beams

2019 ◽  
Vol 275 ◽  
pp. 01026
Author(s):  
Chenjie Zhao ◽  
Xiaohong Xiong ◽  
Zhenhua Xiong ◽  
Kangwen Wu ◽  
Zhen Cao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Elastic Modulus ◽  
Standard Deviation ◽  
Cross Section ◽  
Beam Theory ◽  
Bending Moment ◽  
Modulus Of Rupture ◽  
Loading Process ◽  
The Mean

Six specimens were made and tested to study the mechanical properties of LBL beams. The mean ultimate loading value is 68.39 MPa with a standard deviation of 6.37 MPa, giving a characteristic strength (expected to be exceeded by 95% of specimens) of 57.91 MPa, and the mean ultimate deflection is 53.3 mm with a standard deviation of 5.5 mm, giving the characteristic elastic modulus of 44.3 mm. The mean ultimate bending moment is 20.18 kN.m with a standard deviation of 1.88 kN.m, giving the characteristic elastic modulus of 17.08 kN.m. The mean elastic modulus is 9688 MPa with a standard deviation of 1765 MPa, giving the characteristic elastic modulus of 6785 MPa, and the mean modulus of rupture is 93.3 MPa with a standard deviation of 8.6 MPa, giving the characteristic elastic modulus of 79.2 MPa. The strain across the cross-section for all LBL beams is basically linear throughout the loading process, following standard beam theory.

scholarly journals Bond Behavior of Reinforcing Steel Bars in Thermal Insulation Concrete Exposed to Freeze-Thaw Cycles

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Jinsong Tu ◽  
Ming Zhou ◽  
Yuanzhen Liu ◽  
Y. Frank Chen
Keyword(s):  
Mechanical Properties ◽  
Thermal Insulation ◽  
Ct Scanning ◽  
Reinforcing Steel ◽  
Freezing And Thawing ◽  
Scanning Method ◽  
Bond Behavior ◽  
Freeze Thaw ◽  
Bond Performance ◽  
Steel Bars

An experimental study on the bond behavior of reinforcing steel bars in thermal insulation concrete (TIC) mixed with glazed hollow beads (GHBs) and exposed to freeze-thaw (F-T) cycles was carried out. In order to investigate the effects of GHBs on freezing and thawing, the experimental results were compared with those of normal concrete (NC). The comparison shows that, after 300 F-T cycles, both bond behavior and mechanical properties of the TIC specimens are better than those of the NC specimens. Furthermore, in order to investigate the mechanism of frost effect on TIC, the CT scanning method was used to investigate the evolution of the inner structure of a TIC specimen exposed to F-T cycles. The CT images show that the deterioration of bond performance and mechanical properties of the TIC specimen appears to be caused by the increase of micropores in the TIC.

scholarly journals Chemical and Mechanical Properties of Reinforcing Steel Bars from Local Steel Plants

2019 ◽  
Vol 19 (4) ◽  
pp. 1067-1076
Author(s):  
Jamiu Kolawole Odusote ◽  
Wasiu Shittu ◽  
Adekunle Akanni Adeleke ◽  
Peter Pelumi Ikubanni ◽  
Olumide Adeyemo
Keyword(s):  
Mechanical Properties ◽  
Reinforcing Steel ◽  
Steel Bars

Numerical Solution of Section Stress about Steel-Concrete Composite Beams

2010 ◽  
Vol 163-167 ◽  
pp. 1614-1619
Author(s):  
Hai Gen Cheng ◽  
Yan Lou Yu ◽  
Yong Zhang
Keyword(s):  
Differential Equation ◽  
Cross Section ◽  
Beam Theory ◽  
Composite Beams ◽  
Nonuniform Distribution ◽  
Concrete Slabs ◽  
Shear Lag ◽  
Box Girder ◽  
Simply Supported ◽  
Lag Effect

Steel-concrete composite beams are composed of concrete slabs and steel girders by shear connectos. Due to the shear lag effect, the longitudinal normal stress of cross section is nonuniform distribution,and it is difficult to analyse the effect of that by ordinary beam theory. A differential equation of equilibrium is constituted corresponding to the compatibility of deformation and the equilibrium of forces about steel-concrete composite beams under particular assumed condition. The method of variable-separating is applied to solve the differential equation with the simply supported boundary condition. An example of steel-concrete composite box girder is given to analyse the effect of shear lag on its stress and approve its applicability.

Stresses in a Reinforced Monocoque Cylinder Under Concentrated Symmetric Transverse Loads

1944 ◽  
Vol 11 (4) ◽  
pp. A235-A239
Author(s):  
N. J. Hoff
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Cross Section ◽  
Maximum Shear Stress ◽  
Circular Cross Section ◽  
Bending Moment ◽  
Normal Stress Distribution ◽  
Transverse Loads ◽  
Conventional Analysis ◽  
Analysis Application

Abstract The stresses in the sheet covering, stringers, and rings of a reinforced monocoque cylinder of circular cross section are calculated for the case of a loading consisting of concentrated symmetric forces applied to the rings in the planes of the rings. The conventional assumptions of a linear normal stress distribution and a corresponding shear-stress distribution in the bent cylinder are replaced by a least-work analysis. Application of the theory to the numerical example of a cantilever monocoque cylinder yields a maximum shear stress in the sheet covering and a maximum bending moment in the ring amounting to 900 per cent and 33 per cent, respectively, of the values obtained by the conventional analysis.

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