Study of Fatigue Tests on the Structural Details of Welding Joints of Integral Bridge Deck and Main Girder Gusset Plates

2011 ◽  
Vol 243-249 ◽  
pp. 1638-1645
Author(s):  
Cai Ping Huang ◽  
Zhong Xian Zhang ◽  
Ji Zhang ◽  
Jin Zhou Chen
Keyword(s):  
Fatigue Life ◽  
Bridge Deck ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Scale Model ◽  
Gusset Plates ◽  
Integral Bridge ◽  
Structural Details ◽  
Tensile Forces ◽  
Welding Joints

Under the action of both dead and live loads, the welding joints of the integral bridge deck and the main truss gusset plates of a steel truss bridge in the transverse and longitudinal directions are all subjected to tensile force, the fatigue performance of which greatly influence the safety and durability of the bridge during operation. Fatigue tests were carried out on a full-scale model designed and made in accordance with the structural details of the welding joints of the integral bridge deck and the main truss gusset plates of Dashengguan Changjiang River Bridge. On the basis of the results of the fatigue tests, the stress distribution of the welding joints was analyzed, the fatigue life of the welding joints under load cycles with constant amplitude was discussed and the fatigue performance of the welding joints under the condition of two-way tensile forces was studied. It is concluded that under the effect of fatigue loading with given amplitude, the fatigue life of the welding joints is more than 200 million numbers of load cycles, the structural details of welding joints have ample fatigue resistant ability under the condition of two-way tensile forces, and the maximum main stress value of the fatigue tests is lower than the allowable fatigue stress value given in various codes and relevant references and the fatigue strength meets requirement.

scholarly journals Experimental study on fatigue performance of Q420qD high-performance steel cross joint in complex environment

2021 ◽  
Author(s):  
Haigen Cheng ◽  
Cong Hu ◽  
Yong Jiang
Keyword(s):  
Fatigue Life ◽  
High Performance ◽  
Steel Structure ◽  
Steel Structures ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Corrosive Media ◽  
Joint Connection ◽  
High Performance Steel ◽  
The Cross

AbstractThe steel structure under the action of alternating load for a long time is prone to fatigue failure and affects the safety of the engineering structure. For steel structures in complex environments such as corrosive media and fires, the remaining fatigue life is more difficult to predict theoretically. To this end, the article carried out fatigue tests on Q420qD high-performance steel cross joints under three different working conditions, established a 95% survival rate $$S{ - }N$$ S - N curves, and analyzed the effects of corrosive media and high fire temperatures on its fatigue performance. And refer to the current specifications to evaluate its fatigue performance. The results show that the fatigue performance of the cross joint connection is reduced under the influence of corrosive medium, and the fatigue performance of the cross joint connection is improved under the high temperature of fire. When the number of cycles is more than 200,000 times, the design curves of EN code, GBJ code, and GB code can better predict the fatigue life of cross joints without treatment, only corrosion treatment, and corrosion and fire treatment, and all have sufficient safety reserve.

The Effect of Asphalt Binder Aging on Fatigue Performance of Evotherm WMA

2012 ◽  
Vol 535-537 ◽  
pp. 1686-1692
Author(s):  
Yong Chun Qin ◽  
Sui Yuan Wang ◽  
Wei Zeng ◽  
Xiao Pei Shi ◽  
Jian Xu ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Asphalt Binders ◽  
Different Temperatures ◽  
Binder Aging ◽  
Lower Production

One of the main benefits advertised with the use of warm mix asphalt (WMA) is the decreasing aging of the asphalt binder resulting from the lower production temperature compared to conventional hot mix asphalt (HMA). Some tests were performed to determine the asphalt binder aging properties from WMA and HMA. Asphalt binders were recovered by extraction and distillation from asphalt mixtures premixed at different temperatures (140°C, 160°C, 180°C for HMA, 100°C and 120°C for WMA) in the mixing plant. Penetration@25°C, softening point (R&B) and rotational Brookfield viscosity tests were carried out. Results show that the aging of asphalt binder increases as the mixing temperature is elevated, and remarkably accelerates at the temperatures higher than 150°C. Warm mix asphalt (for example, mixing temperature at 100°Cor 120°C) can greatly reduce the aging of asphalt. Aging of the asphalt binder is one of the factors that would affect the mixture’s fatigue life. Four-point beam fatigue test samples were mixed and compacted at 140°C for HMA and 120°C for WMA, and fatigue tests with a frequency of 10 Hz and three constant strain levels (150 micro-strain, 300 micro-strain, 450 micro-strain, respectively) were performed. Results show that WMA’s fatigue life was higher than the control HMA, which indicates that it may reduce aging of asphalt binder and improve fatigue performance of asphalt mixture at lower production temperatures.

scholarly journals Span Length Variance Effect on the Fatigue Life of FRP Bridge Deck

2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
Ki-Tae Park ◽  
Young-Jun Yu ◽  
Hyunseop Shin
Keyword(s):  
Fatigue Life ◽  
Life Cycle Cost ◽  
Bridge Deck ◽  
Safety Margin ◽  
Fatigue Tests ◽  
Span Length ◽  
Reinforced Composite ◽  
Frp Bridge Deck ◽  
Change Trend ◽  
Truck Load

Fiber reinforced composite materials have the merits of light weight and durability for bridge deck and are estimated to be superior in economy to conventional deck materials considering the life-cycle cost of bridge. In this study, fatigue tests were conducted for the span lengths of 2.0 m and 2.5 m in order to investigate the change trend of fatigue characteristics of composite material deck according to the change in the span length. The result showed that the fatigue life rapidly reduces to about 25% when the span increases by 25%. However, considering that the fatigue performance safety margin was approximately 1.6 times more than the design axle load of the DB-24 design truck load in Korea, even at the span of 2.5 m, it is judged that the FRP decks being considered can be effectively used at a span length of 2.5 m.

scholarly journals Shear Fatigue Performance of Epoxy Resin Waterproof Adhesive Layer on Steel Bridge Deck Pavement

2021 ◽  
Vol 7 ◽  
Author(s):  
Ying Xu ◽  
Xinpeng Lv ◽  
Chunfeng Ma ◽  
Fengming Liang ◽  
Jiafei Qi ◽  
...  
Keyword(s):  
Shear Strength ◽  
Fatigue Life ◽  
Epoxy Resin ◽  
Bridge Deck ◽  
Adhesive Layer ◽  
Fatigue Performance ◽  
Steel Bridge ◽  
Shear Fatigue ◽  
Interlaminar Shear ◽  
Bridge Deck Pavement

In this study, the effects of temperature, shear stress, and coating quantity of waterproof adhesive layer on the shear fatigue performance of a steel bridge deck pavement were investigated. Direct shear fatigue tests of a pavement comprising an epoxy resin waterproof adhesive layer with stone matrix asphalt were conducted at different temperatures, stress levels, and coating quantities. The results show that temperature and stress have significant effects on the shear fatigue life. With increasing temperature and stress, the shear fatigue life of the waterproof adhesive layer decreased gradually. Therefore, for steel bridge deck pavements under high temperatures and heavy loads, the use of asphalt waterproof adhesive layers or pavement layers should be evaluated carefully while limiting the traffic of heavily loaded vehicles. Shear failure occurs at the waterproof adhesive layer–pavement interface and not at the steel–waterproof adhesive layer interface. The shear strength of the epoxy resin waterproof adhesive layer is mainly provided by the bond strength between the waterproof adhesive and pavement mixture as well as the interlocking force between the cured epoxy resin and the bottom interface of uneven pavement mixture. The shear strength increases with the coating quantity of the waterproof adhesive layer; however, after reaching the maximum value, the shear strength becomes stable. In contrast, the interlaminar shear fatigue life increases continuously with the coating quantity of the waterproof adhesive layer. Appropriately increasing the coating quantity is beneficial for improving the resistance of the waterproof adhesive layer to interlaminar shear fatigue failure.

scholarly journals Effects of Machining Induced Residual Shear and Normal Stresses on Fatigue Life and Stress Intensity Factor of Inconel 718

2019 ◽  
Vol 9 (22) ◽  
pp. 4750
Author(s):  
Yang Hua ◽  
Zhanqiang Liu
Keyword(s):  
Experimental Data ◽  
Stress Intensity Factor ◽  
Fatigue Life ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Inconel 718 ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Shear Stresses ◽  
Normal Stresses

Residual shear stresses and normal stresses induced by machining affect the fatigue performance of components. Thus, residual shear and normal stresses should be considered simultaneously when evaluating the influence of residual stress on fatigue performance. In the present paper, the influences of residual shear and normal stresses on the fatigue life and stress intensity factor (SIF) of turned Inconel 718 were investigated. Firstly, the cos α measurement method was utilized to calculate the residual shear stress and residual normal stress of turned Inconel 718. Then, the combined effects of residual shear and normal stresses on fatigue life were evaluated through uniaxial tension–tension fatigue tests. Thirdly, a prediction model for the SIF was proposed by taking the residual shear and normal stresses into account. Finally, the predicted SIF was validated by the published experimental data from the literature. The predicted results of the proposed model generally agreed well with the available experimental data.

scholarly journals Comparison of Internal and External Hydrogen on Fatigue-Life of Austenitic Stainless Steels

2016 ◽  
Author(s):  
Paul J. Gibbs ◽  
Chris San Marchi ◽  
Kevin A. Nibur ◽  
Xiaoli Tang
Keyword(s):  
Fatigue Life ◽  
Stainless Steels ◽  
Life Stress ◽  
Maximum Stress ◽  
Austenitic Stainless Steels ◽  
Fatigue Tests ◽  
Gaseous Hydrogen ◽  
Fatigue Performance ◽  
Notched Specimens ◽  
Internal Hydrogen

The degradation of stress-controlled fatigue-life (stress-life) of notched specimens was measured in the presence of internal and in external hydrogen for two strain-hardened austenitic stainless steels: 316L and 21Cr-6Ni-9Mn. To assess the sensitivity of fatigue performance to various hydrogen conditions fatigue tests were performed in four environments: (1) in air with no added hydrogen, (2) in air after hydrogen pre-charging to saturate the steel with internal hydrogen, and in external gaseous hydrogen at pressure of (3)10 MPa (1.45 ksi), or (4) 103 MPa (15 ksi). The fatigue performance of the strain-hardened 316L and 21Cr-6Ni-9Mn steels in air was indistinguishable for the tested conditions. Decreases in the fatigue-life at a given stress level were measured in the presence of hydrogen and depended on the hydrogen environment. Testing in 103 MPa (15 ksi) external gaseous hydrogen always resulted in a clear decrease in the fatigue-life at a given maximum stress. Alloy dependent reductions in the observed life at a given maximum stress were observed in the presence of internal hydrogen or in gaseous hydrogen at a pressure of 10 MPa (1.45 ksi). The measured fatigue-life of hydrogen pre-charged specimens was comparable to the life with no intentional hydrogen additions. Accounting for the increased flow stress resulting from the supersaturation of hydrogen after pre-charging results in consistency between the measured fatigue-life of the pre-charged condition and measurements in 103 MPa (15 ksi) external hydrogen. The current results indicate that internal hydrogen may be an efficient method to infer hydrogen-assisted fatigue degradation of stainless steels in high-pressure gaseous hydrogen.

scholarly journals Fatigue Performance of Wet and Dry Pulverized Wood Flour Reinforced PP Composites

2019 ◽  
Vol 3 (1) ◽  
pp. 20 ◽  
Author(s):  
Md Haque ◽  
Koichi Goda ◽  
Hirokazu Ito ◽  
Shinji Ogoe ◽  
Masaki Okamoto ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Wood Flour ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Test Results ◽  
Polypropylene Composites ◽  
Different Types ◽  
Pine Trees ◽  
Negative Effect ◽  
Positive Effect

In this paper, we exclusively studied the effects of dry and wet pulverization of different wood flours on the fatigue performance of polypropylene (PP)/wood flour (WF) composites. Wood flours obtained from cypress and Scots pine trees were pulverized in both dry and wet conditions at two different mill-plate gaps, 200 µm and 350 µm, and were used as reinforcement in PP matrices. Master batches of PP with different types of pulverized WF were compounded before processing in an extruder. The PP/WF composites of initial WF were also prepared for comparison. The prepared composites were analyzed by tensile and fatigue tests. It was found that the tensile properties of wood/polypropylene composites were affected by the pulverization of WF. Fatigue test results displayed that wet pulverization of short cypress flour had a negative effect on the fatigue life of PP/WF composites, while wet pulverization of long cypress flour and pine flour had a positive effect on the fatigue life of PP/WF composites.

scholarly journals Effect of Surface Integrity on Hot Fatigue Life of Ti2AlNb Intermetallic Alloy

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4841
Author(s):  
Yanju Wang ◽  
Yi Zhou ◽  
Aixue Sha ◽  
Xingwu Li
Keyword(s):  
Surface Layer ◽  
Fatigue Life ◽  
Surface Integrity ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Microhardness Distribution ◽  
Ti2alnb Alloy ◽  
Standard Specimens ◽  
Effect Of Surface

The effect of surface integrity on the hot fatigue performance of Ti2AlNb alloy was investigated. A turning process was used to prepare the standard specimens for hot fatigue tests. The surface integrity characterization and axial fatigue tests were performed. The results show that the influence of surface roughness on the hot fatigue performance of the Ti2AlNb alloy is a secondary factor. The compressive residual stress and enhanced microhardness in the surface layer has a significant effect on the hot fatigue life and they are dominant in the hot fatigue behavior of the Ti2AlNb alloy. Through the investigation on the characteristics of the fatigue fractures, the fatigue propagation process was significantly suppressed because of the strong residual compressive stress and microhardness distribution on the surface layer of the Ti2AlNb specimen.

Experimental Studies on the Full-Scale Fatigue Performance of X65 Marine Pipeline

2014 ◽  
Vol 1052 ◽  
pp. 555-560
Author(s):  
Yan Hua Hu ◽  
De Yu Tang ◽  
Zong Tao Fang ◽  
Hu Li Niu
Keyword(s):  
Fatigue Life ◽  
Experimental Studies ◽  
Fatigue Tests ◽  
Full Scale ◽  
Welding Residual Stress ◽  
Fatigue Performance ◽  
Four Point Bending ◽  
Inner Pressure ◽  
Quantitative Basis ◽  
Safety Operation

In this paper, the fatigue performance of X65 marine pipeline is domestically studied by means of full-scale fatigue tests (four-point bending + inner pressure), in which all the influencing factors, such as welding residual stress, stress concentration, initial defects, internal pressure shutdown and pressure fluctuation are taken into consideration comprehensively. Consequently, the fatigue cycles under different stress amplitude can be derived and applied to predicting the full-scale fatigue life of pipes quantitatively. Additionally, the test results are compared with the recommended data of international general standards, such as BS 7608 and DNV C203, by which the fatigue safety of pipes could be evaluated. Therefore, this study is not only beneficial to the accumulation of full-scale fatigue data of pipes, but also can provide quantitative basis for evaluating the fatigue life and ensuring the safety operation cycles of pipes.

Crack Pinning in Asphalt Mastic and Concrete: Regular Fatigue Studies

2000 ◽  
Vol 1728 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Benjamin J. Smith ◽  
Simon A. M. Hesp
Keyword(s):  
Particle Size ◽  
Fatigue Life ◽  
Asphalt Concrete ◽  
Filler Particle ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Direct Result ◽  
Asphalt Mastic ◽  
Crack Pinning ◽  
Ground Limestone

The effects of finely dispersed fillers on the fatigue performance of asphalt binders and asphalt concrete mixes at relatively low temperatures are examined. A series of model binder systems containing glass spheres with narrow particle size distributions were used to study the effect of filler particle size on the fatigue performance of the asphalt mastic. Two mastic systems containing ground limestone fillers, which possessed significantly different gradations, also were tested. Fatigue performance was evaluated by applying a constant torsional strain to each specimen in a dynamic rheometer at 10°C and 40 Hz. Testing at various strain levels allowed the relationship between fatigue life and strain to be determined for the different systems. The results indicate that as the particle size of the filler decreases, the fatigue life of the asphalt mastic increases. This observation is a direct result of the mode of fatigue failure in the asphalt mastics and is in agreement with Evans’s theory on crack pinning for failure in filled brittle solids. Constant stress asphalt concrete fatigue tests on both dense- and gap-graded systems prepared with the two different ground limestone fillers show that the particle size does not significantly affect the fatigue life of the mixes. These results also confirm that crack pinning is the major mechanism responsible for improved fatigue performance.

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