scholarly journals Experimental and Analytical Study on Deformation Behavior in Hogging Moment Regions of Composite Beams

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Aiming Song ◽  
Qi Luo ◽  
Shui Wan ◽  
Zhicong Li
Keyword(s):  
Analytical Study ◽  
Fatigue Behavior ◽  
Residual Deformation ◽  
Composite Beams ◽  
Fatigue Tests ◽  
Structural Deformation ◽  
Test Results ◽  
Fatigue Load ◽  
Deformation Curves ◽  
Good Agreement

The results of an experimental and analytical study on the static and fatigue behavior in steel-concrete composite beams under the hogging moment were presented in this paper, and the structural deformation was discussed cautiously and emphatically. Firstly, the static and fatigue tests on three inverted simply supported beams were conducted. The development of cracks under static loading, the load-deformation curves, and the values of residual deformation under fatigue load were recorded and analyzed in detail. Several meaningful conclusions were obtained from the analysis of experimental results. To study the development laws of residual deformation under fatigue load, the analytical methods of residual midspan deflection and residual rebar strain were proposed, respectively. The limitation and accuracy of the presented models were studied according to the comparison between the prediction and measured results. The calculation values of the proposed models showed good agreement with the test results. Finally, the design recommendations of fatigue deformation were proposed according to the experimental and analytical study on steel-concrete composite beams subjected to hogging moment.

High-cycle fatigue tests of pretensioned concrete beams

PCI Journal ◽  
2022 ◽  
Vol 67 (1) ◽  
Author(s):  
Jörn Remitz ◽  
Martin Empelmann
Keyword(s):  
Fatigue Life ◽  
High Cycle Fatigue ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Design Methods ◽  
Test Results ◽  
Cycle Fatigue ◽  
Pretensioned Concrete ◽  
Current Design

Pretensioned concrete beams are widely used as bridge girders for simply supported bridges. Understanding the fatigue behavior of such beams is very important for design and construction to prevent fatigue failure. The fatigue behavior of pretensioned concrete beams is mainly influenced by the fatigue of the prestressing strands. The evaluation of previous test results from the literature indicated a reduced fatigue life in the long-life region compared with current design methods and specifications. Therefore, nine additional high-cycle fatigue tests were conducted on pretensioned concrete beams with strand stress ranges of about 100 MPa (14.5 ksi). The test results confirmed that current design methods and specifications overestimate the fatigue life of embedded strands in pretensioned concrete beams.

scholarly journals Investigation of the Mechanical Behavior of Partially Precast Partially Encased Assembled Composite Beams

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Liufeng Zhang ◽  
Yinghua Yang
Keyword(s):  
Mechanical Properties ◽  
Composite Beam ◽  
Low Cost ◽  
Concrete Strength ◽  
Composite Beams ◽  
Test Results ◽  
Structural Form ◽  
Heavy Load ◽  
Grade Steel ◽  
Good Agreement

In view of the characteristics of a high floor and the heavy load of logistics buildings, a partially prefabricated partially encased assembled composite beam (PPEC) is proposed in order to achieve the low cost construction of such buildings. In this research, the mechanical properties of PPEC beams were studied experimentally. The effects of the concrete strength grade, steel content, shear span ratio, and fabrication methods on the mechanical properties of the PPEC beams were analyzed. The results showed that the proposed structural form of the PPEC beams was generally feasible. Based on the test results, a practical shear formula for PPEC beams was proposed, and the calculated results were in good agreement with the test results.

Mathematical Modeling of Ultra-High-Pressure Waterjet Peening

2005 ◽  
Vol 127 (2) ◽  
pp. 186-191 ◽  
Author(s):  
S. Kunaporn ◽  
M. Ramulu ◽  
M. Hashish
Keyword(s):  
Mathematical Modeling ◽  
High Pressure ◽  
High Cycle Fatigue ◽  
Fatigue Tests ◽  
Analytical Models ◽  
Test Results ◽  
Ultra High Pressure ◽  
Proposed Model ◽  
Compressive Residual Stresses ◽  
Good Agreement

Waterjet peening is a recent promising method in surface treatment. It has the potential to induce compressive residual stresses that benefit the fatigue life of materials similar to the conventional shot peening process. However, there are no analytical models that incorporate process parameters (i.e., supply pressure, jet exposure time, and nozzle traverse rate, etc) to allow predicting the optimized peening process. Mathematical modeling of high-pressure waterjet peening was developed in this study to describe the relation between the waterjet peening parameters and the resulting material modifications. Results showed the possibility of using the proposed mathematical model to predict an initial range for effective waterjet peening under the variation of waterjet peening conditions. The high cycle fatigue tests were performed to validate the proposed model and fatigue test results showed good agreement with the predictions.

Biomechanical analysis of spinal implants with different rod diameters under static and fatigue loads: an experimental study

2019 ◽  
Vol 64 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Halim Kovacı ◽  
Ali Fatih Yetim ◽  
Ayhan Çelik
Keyword(s):  
Dynamic Compression ◽  
Fatigue Behavior ◽  
Pedicle Screws ◽  
Fatigue Tests ◽  
Biomechanical Analysis ◽  
Static Tension ◽  
Test Results ◽  
Spinal Implants ◽  
Biomechanical Behavior ◽  
Load Carrying

Abstract Spinal implants are commonly used in the treatment of spinal disorders or injuries. However, the biomechanical analyses of them are rarely investigated in terms of both biomechanical and clinical perspectives. Therefore, the main purpose of this study is to investigate the effects of rod diameter on the biomechanical behavior of spinal implants and to make a comparison among them. For this purpose, three spinal implants composed of pedicle screws, setscrews and rods, which were manufactured from Ti6Al4V, with diameters of 5.5 mm, 6 mm and 6.35 mm were used and a bilateral vertebrectomy model was applied to spinal systems. Then, the obtained spinal systems were tested under static tension-compression and fatigue (dynamic compression) conditions. Also, failure analyses were performed to investigate the fatigue behavior of spinal implants. After static tension-compression and fatigue tests, it was found that the yield loads, stiffness values, load carrying capacities and fatigue performances of spinal implants enhanced with increasing spinal rod diameter. In comparison to spinal implants with 5.5 mm rods, the fatigue limits of implants showed 13% and 33% improvements in spinal implants having 6 mm and 6.35 mm rods, respectively. The highest static and fatigue test results were obtained from spinal implants having 6.35 mm rods among the tested implants. Also, it was observed that the increasing yield load and stiffness values caused an increase in the fatigue limits of spinal implants.

High-Cycle Fatigue Behavior of Type 4340 Steel Pressurized Blocks Including Mean Stress Effect

2019 ◽  
Author(s):  
Elie A. Badr ◽  
Joanne Ishak
Keyword(s):  
Stress Ratio ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Ultimate Stress ◽  
Stress Effect ◽  
Mean Stress ◽  
Test Results ◽  
Linear Correction ◽  
The Mean

Abstract Mean stress effects in pressurized steel blocks were examined under constant amplitude fatigue loading. The tests were performed to provide experimental data needed to study the effect of mean stress on fatigue lives of subject specimen, and to substantiate the use of analytical expressions to account for the mean stress. The mean stress was the result of subjecting the specimens to an autofrettage pressure which induced compressive residual stresses at the crossbore intersection of the specimens. Fatigue tests were carried out under both tensile and compressive mean stress levels. Test results were compared to several mean stress accounting relationships such as the Smith-Watson Topper, Bergmann and Seeger, modified Goodman, Gerber and Soderberg. Test results indicated that the modified Goodman equation is favorable in accounting for the effect of both tensile and compressive mean stresses on fatigue life (up to a compressive mean stress to ultimate stress ratio of −0.2). The behavior under compressive mean stress to ultimate stress ratio of less than −0.2 indicated that a linear correction relationship was required.

Low-Cycle Fatigue Behavior of Small Slice Specimens of Zircaloy-4 at Elevated Temperature

2006 ◽  
Vol 324-325 ◽  
pp. 1241-1244 ◽  
Author(s):  
Li Xun Cai ◽  
Yu Ming Ye
Keyword(s):  
Elevated Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Fatigue Tests ◽  
Uniaxial Strain ◽  
Transverse Strain ◽  
Test Results ◽  
Element Analysis

A series of strain fatigue tests were carried out on small bugle-like slice-specimens of Zr-4 alloy at 20 and 400. According to Elastic and Plastic Finite Element Analysis and assumption of local damage equivalence, a strain formula was given to transform transverse strain of the specimen to uniaxial strain. Based on the test results of the alloy and the strain transform formula, M-C (Manson-Coffin) models to be used for estimating uniaxial fatigue life of Zr-4 alloy were obtained. The results show that, the alloy mainly behaves as cyclic softening at 20 and as cyclic hardening at 400, and the elevated temperature can lead serious additional fatigue damage of the alloy and the effect of the elevated temperature impairs gradually with increasing of amplitude strain. A conclusion is helpful that prediction life by using M-C model based on traditional strain transform equation is quite conservative when uniaxial strain amplitude is less than 0.5%.

An Overview of the Fatigue of Polychloroprene Rubber

2014 ◽  
Vol 891-892 ◽  
pp. 518-523
Author(s):  
Jean Louis Poisson ◽  
Florian Lacroix ◽  
Stéphane Méo ◽  
Gaelle Berton ◽  
Narayanaswami Ranganathan
Keyword(s):  
Fatigue Behavior ◽  
Viscoelastic Behavior ◽  
Fatigue Tests ◽  
Test Results ◽  
Biaxial Fatigue ◽  
Synthetic Rubber ◽  
Strain Induced Crystallization ◽  
Life Enhancement ◽  
Induced Crystallization

Some fundamental studies carried in a synthetic rubber - Chloroprene CR29 are presented in the first part of the paper. A critical analysis of test results, shows that an energy based approach permits the determination of fatigue lives in this material. This aspect is further enhanced by biaxial fatigue tests in the same material. These tests covering a life range from 10000 to 1000000 cycles show that the energy based model is very efficient to describe the fatigue behavior. Some evidence of strain induced crystallization (previously observed in natural rubber) with associated life enhancement at high load ratios is also presented. A comprehensive model based on the determination of the constitutive laws taking into account the viscoelastic behavior is developed showing excellent correlation with experimental data.

Fatigue Properties of Titanium Alloy TA11 under Multiaxial Loadings with Tension - Bending Vibration

2014 ◽  
Vol 887-888 ◽  
pp. 873-877
Author(s):  
Bin Li ◽  
Nan Ma ◽  
Xin Ling Liu ◽  
Zhi Wang Qiu ◽  
Hong Ren Li
Keyword(s):  
Titanium Alloy ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Loading Conditions ◽  
Test Results ◽  
Bending Vibration ◽  
Alpha Titanium ◽  
Vibration Loads ◽  
Multiaxial Loadings

This paper studied the fatigue behavior of the near alpha titanium alloy TA11 under multiaxial loading conditions with tension - bending vibration, to simulate the service stress state applied on the engine blades, where a large centrifugal force is superimposed with bending vibration loads. A plate-like specimen was used in the fatigue tests with different ratios between the tension and bending vibration loads, then, the energy based fatigue criteria were applied for correlation of the test results. The fatigue properties of titanium alloy TA11 under the specialized loading conditions are characterized and discussed.

scholarly journals Experimental and Analytical Study of Horizontally Curved I-Girders Subjected to Equal End Moments

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1132
Author(s):  
Jeonghyeon Lim ◽  
Young-Jong Kang ◽  
Jeonghwa Lee ◽  
Seungjun Kim ◽  
Keesei Lee
Keyword(s):  
Analytical Study ◽  
Experimental Studies ◽  
Bending Moment ◽  
Test Results ◽  
Ultimate State ◽  
Moment Capacity ◽  
Horizontally Curved ◽  
Stiffness Reduction ◽  
Interaction Curves ◽  
Good Agreement

If bending and torsional moments are applied to an I-shaped beam member, the coupling of those two forces could reduce the bending moment capacity of that member. Therefore, the interaction between bending and torsional moments is an important issue for horizontally curved members that are always simultaneously subjected to bending and torsion. In this study, the behavior of the horizontally curved steel I-beam was investigated through numerical analysis. The ultimate state of sharply curved members that showed large displacement was defined in accordance with the stiffness reduction ratio to consist of strength curves. Based on the analysis results, interaction curves were established, and a strength equation was derived. The uniform torsional moment capacity, curvature, and slenderness parameters were considered in the equation, which were the main factors that affected the ultimate strength of curved members. The curvature effect was considered individually, so that the strength of the straight or curved girder could be estimated with a unified equation. To verify the accuracy of the suggested equation, experimental studies were also conducted. Consequently, the suggested equation shows very good agreement with the test results, and is expected to provide useful information for the design of curved members.

Fatigue Behavior and Deformation of Aluminum and Steel HVOF Sprayed with WC-Co Coatings

1997 ◽  
Author(s):  
A. Ibrahim ◽  
C.C. Berndt
Keyword(s):  
Fatigue Life ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Three Dimensional ◽  
Element Model ◽  
Fatigue Tests ◽  
Dimensional Finite Element ◽  
Life Distributions ◽  
Three Dimensional Finite Element ◽  
Good Agreement

Abstract The effect of WC-Co coating on the high cycle fatigue (HCF) behavior of SAE 12L14 steel and 2024-T4 aluminum was investigated. The fatigue tests were performed at room temperature and 370°C. The fatigue life distributions of specimens in the polished, grit blasted, peened, and coated conditions are presented as a function of the probability of failure. HVOF sprayed WC-Co coating has influenced the fatigue life of aluminum and steel. Factors contributing to this influence, which include grit blasting, elastic modulus, and residual stress, are discussed. A three-dimensional finite-element model (FEM) of the coated specimen was used to calculate the stress distribution across the coating and the substrate. The results of the analytical model are in good agreement with fatigue lives observed experimentally.

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