Structural Response of a Multi-Strand Stay Cable to Cyclic Bending Load

<p>Recent trends towards performance-based fire designs for complex and critical structures have posed questions about the fire resilience of bridge infrastructure. There are little-to-no code requirements for bridge fire resistance and practitioner guidance on the subject is limited. Research on the fire performance of cable-supported bridge structures is scarce and knowledge gaps persist that inhibit more informed fire protection designs in a variety of bridge types. There have been few numerical or experimental studies that investigate the fire performance of steel stay-cables for use in cable-supported bridges. The thermal response of these members is critical as cable systems are highly dependent on the response of individual members, such as in the case of an anchor cable for example. The study herein examines the thermal response of several varieties of unloaded steel- stay cable during exposure to a non-standard methanol pool fire and the implications for the structural response of a cable-supported bridge. Experimental thermal strain data from fire tests of various stay-cables is used to inform high-level insights for the global response of a cable-supported bridge. Namely, the effects of cable thermal expansion on the overall cable system is approximated.</p>

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Failure Behavior of Elbows With Local Wall Thinning Under Cyclic Load

Seismic Engineering, Volume 1 ◽

10.1115/pvp2004-2950 ◽

2004 ◽

Cited By ~ 2

Author(s):

Izumi Nakamura ◽

Akihito Otani ◽

Masaki Shiratori

Keyword(s):

Failure Modes ◽

Seismic Load ◽

Failure Behavior ◽

Cyclic Bending ◽

Wall Thinning ◽

Bending Load ◽

Piping Systems ◽

Out Of Plane ◽

Effects Of Aging ◽

Local Wall Thinning

Pressurized piping systems used in nuclear power plants are supposed to be degraded by the effects of aging. Local wall thinning is one of the defects considered to be caused in piping systems due to the effects of aging, but the failure behavior of thinned wall pipes under seismic load is still not clear. Therefore an experimental and analytical study to clarify the failure behavior of thinned wall pipes is being conducted. In this paper, the experimental results of locally thinned wall elbows under cyclic bending load are described. Displacement-controlled cyclic bending tests were conducted on elbows with local wall thinning. The test models were pressurized to 10MPa with room temperature water and were subjected to in-plane or/and out-of-plane cyclic bending load until their failures. From the tests, the failure modes of the thinned wall elbows were found to be fatigue failure at the flank of the elbow, or fatigue and buckling failure accompanied with ratchet deformation. It was also found that the life of the thinned wall elbow subjected to out-of-plane bending were extremely lower than that of the elbow without wall thinning. The failure modes and fatigue lives of elbows seemed to be affected by a ratchet phenomenon.

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Propagation Behavior of Main Crack in Reinforced Concrete Beams Strengthened with CFRP under Cyclic Bending Load

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.535-536.205 ◽

2013 ◽

Vol 535-536 ◽

pp. 205-208

Author(s):

Zheng Wei Li ◽

Pei Yan Huang ◽

Hao Zhou

Keyword(s):

Reinforced Concrete ◽

Crack Propagation ◽

Main Crack ◽

Fatigue Behavior ◽

Propagation Rate ◽

Reinforced Concrete Beams ◽

Rc Beam ◽

Cyclic Bending ◽

Propagation Behavior ◽

Bending Load

Fatigue behavior of reinforced concrete (RC) beam can be improved by externally bonded fiber reinforced polymer (FRP). However, propagation behavior of a crack on the RC beam will have serious effect on the fatigue life of the beam strengthened with FRP. In this paper, a finite element (FE) procedure was developed to analysis the stress intensity factor (SIF) of the main crack and an experimental study was conducted to investigate the propagation rate of the main crack of the RC beam strengthened with carbon fiber laminate (CFL) under cyclic bending load. The FE analysis results show that the SIF near the main crack tip increases at the beginning and then decreases with the fatigue crack propagation. When relative crack length α is equal to 0.3, the SIF is maximum. When α approaches 0.75, the SIF approaches zero. A total of 3 RC beams strengthened with CFL were tested. The experimental results show that it is possible to divide the process of the crack propagation into three distinct phases, including crack initiation and then quickly propagation, stable propagation and then rest and unstable propagation. A semi-empirical equation based on the Paris Law was developed to predict the crack propagation rate.

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Reliability and Failure Analysis of Lead-Free Solder Joints for PBGA Package Under a Cyclic Bending Load

IEEE Transactions on Components and Packaging Technologies ◽

10.1109/tcapt.2008.921650 ◽

2008 ◽

Vol 31 (2) ◽

pp. 478-484 ◽

Cited By ~ 20

Author(s):

Ilho Kim ◽

Soon-Bok Lee

Keyword(s):

Failure Analysis ◽

Solder Joints ◽

Lead Free ◽

Lead Free Solder ◽

Cyclic Bending ◽

Bending Load ◽

Free Solder

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Evaluation of material behavior of wire strips under cyclic bending load and preparation of an experimental test method

10.25518/esaform21.3826 ◽

2021 ◽

Author(s):

Alina Biallas ◽

Marion Merklein

Keyword(s):

Experimental Test ◽

Kinematic Hardening ◽

Strain Curve ◽

Test Method ◽

Material Behavior ◽

Steel Fibers ◽

Compression Tests ◽

Process Step ◽

Cyclic Bending ◽

Bending Load

Steel fibers as concrete reinforcement improve the building material’s mechanical properties and enlarges its field of application. The production of steel fibers by the process chain notch rolling and cyclic bending promises energetic improvement compared to the conventional manufacturing process wire drawing. The innovative procedure is not yet researched extensively and modelling of the material behavior brings with it many challenges. Different stress states of both process steps require various material models and material failure must be considered. The study brings an appropriate modelling of the test sheet metal DP600 with a thickness of t0=0.8 mm for the second process step into focus. The wire strip’s notches are exposed to a cyclic tension-compression load for which high strength steel exhibits early yielding and a distinct transient region of the stress-strain curve after load reversal. For this reason, the isotropic-kinematic hardening model by Chaboche and Rousselier determined in tension-compression tests is validated by cyclic bending tests. For considering crack initiation, an appropriate ductile damage model for depicting material fatigue is identified. To allow practical realization of the process and validation of the material model, an experimental test method for manufacturing wire strip samples by notch stamping is introduced.

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Ratcheting Studies on Type 304LN Stainless Steel Elbows subjected to Combined Internal Pressure and In-Plane Bending Moment

Journal of Pressure Vessel Technology ◽

10.1115/1.4005886 ◽

2012 ◽

Vol 134 (4) ◽

Cited By ~ 3

Author(s):

S. Vishnuvardhan ◽

G. Raghava ◽

P. Gandhi ◽

M. Saravanan ◽

D. M. Pukazhendhi ◽

...

Keyword(s):

Stainless Steel ◽

Internal Pressure ◽

Accumulation Rate ◽

Bending Moment ◽

Cyclic Bending ◽

Ratcheting Strain ◽

Bending Load ◽

304Ln Stainless Steel ◽

Number Of Cycles ◽

Opening And Closing

“Ratcheting” is a phenomenon which leads to reduction in fatigue life of a structural component by loss of ductility due to cycle by cycle accumulation of plastic strain. Ratcheting occurs in a structure subjected to a combination of steady/sustained and cyclic loads such that the material response is in inelastic region. Ratcheting studies were carried out on Type 304LN stainless steel elbows, subjected to steady internal pressure and cyclic bending. The elbows filled with water were pressurized between 27.6 MPa and 39.2 MPa. Cyclic bending load, under opening and closing moments, was applied on the elbows at ambient temperature. Number of cycles corresponding to occurrence of a through-wall crack was recorded. Crack was observed in the bent portion at one of the crown locations in all the four specimens. Maximum strain was observed at the intrados and crown locations of the elbows. The ratcheting strain increased with number of cycles at crown and intrados locations. However, the strain accumulation rate decreased with number of cycles. Strain was observed to be minimum at the extrados location and the same stabilized toward the end of the tests. The specimens have failed by occurrence of through-wall axial crack accompanied by simultaneous ballooning. The ballooning was found to be varying from 3.8% to 5.8% with respect to the original circumference in the bent portion. The reduction in thickness was found to be around 12%–15%.

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