scholarly journals FATIGUE RESISTANCE AND FAILURE MODES ON RC SLAB OVERLAID CONCRETE USING ADHESIVES

2009 ◽  
Vol 63 (1) ◽  
pp. 538-545
Author(s):  
Tetsukazu KIDA ◽  
Tadashi ABE ◽  
Takayoshi KODAMA ◽  
Kiyoshi ITO
Keyword(s):  
Fatigue Resistance ◽  
Failure Modes ◽  
Rc Slab

scholarly journals Fatigue Resistance and Failure Behavior of Penetration and Non-Penetration Laser Welded Lap Joints

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xiangzhong Guo ◽  
Wei Liu ◽  
Xiqing Li ◽  
Haowen Shi ◽  
Zhikun Song
Keyword(s):  
Fatigue Resistance ◽  
Failure Modes ◽  
Plate Thickness ◽  
High Stress ◽  
Lap Joints ◽  
Failure Behavior ◽  
Passenger Cars ◽  
Plate Fracture ◽  
The Difference ◽  
Railway Passenger

AbstractPenetration and non-penetration lap laser welding is the joining method for assembling side facade panels of railway passenger cars, while their fatigue performances and the difference between them are not completely understood. In this study, the fatigue resistance and failure behavior of penetration 1.5+0.8-P and non-penetration 0.8+1.5-N laser welded lap joints prepared with 0.8 mm and 1.5 mm cold-rolled 301L plates were investigated. The weld beads showed a solidification microstructure of primary ferrite with good thermal cracking resistance, and their hardness was lower than that of the plates. The 1.5+0.8-P joint exhibited better fatigue resistance to low stress amplitudes, whereas the 0.8+1.5-N joint showed greater resistance to high stress amplitudes. The failure modes of 0.8+1.5-N and 1.5+0.8-P joints were 1.5 mm and 0.8 mm lower lap plate fracture, respectively, and the primary cracks were initiated at welding fusion lines on the lap surface. There were long plastic ribs on the penetration plate fracture, but not on the non-penetration plate fracture. The fatigue resistance stresses in the crack initiation area of the penetration and non-penetration plates calculated based on the mean fatigue limits are 408 MPa and 326 MPa, respectively, which can be used as reference stress for the fatigue design of the laser welded structures. The main reason for the difference in fatigue performance between the two laser welded joints was that the asymmetrical heating in the non-penetration plate thickness resulted in higher residual stress near the welding fusion line.

Study on the effect of length–short side ratio on the fatigue performance of the rib girder bridge's carriageway slab

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tianlai Yu ◽  
Linlin Zhang ◽  
Zizheng Liu
Keyword(s):  
Reinforced Concrete ◽  
Fatigue Failure ◽  
Fatigue Resistance ◽  
Failure Modes ◽  
Group Structure ◽  
Load Level ◽  
Fatigue Performance ◽  
Short Side ◽  
Content Type ◽  
Side Ratio

PurposeThe fatigue problems of the carriageway slabs of reinforced concrete rib-beam bridges were studied. The analysis of the carriageway slabs could not achieve the actual stress state.Design/methodology/approachBased on this characteristic, the reinforced concrete T-beam group structure system was taken as the research object. Four scale models of the carriageway slabs of reinforced concrete ribbed bridges were designed. The fatigue failure modes and actual fatigue resistance of the carriageway slabs with different length-to-side ratios were systematically studied through static load and fatigue experiments. Based on this, the concrete damage plasticity model (CDP model) was combined with numerical simulation analysis to study the influence of the length-to-short-side ratio of the carriageway slab on the fatigue performance and the remaining bearing capacity.FindingsThe results show that the fatigue failure of the carriageway slab is a three-stage failure; the ratio of the long and short sides has a significant effect on the fatigue performance of the carriageway slab. Under the same fatigue load level, the smaller the ratio of the long and short sides of the carriageway slab.Originality/valueThe fatigue resistance of the unidirectional board is significantly lower than that of the bidirectional board. It is recommended to use the bidirectional board in actual engineering design.

scholarly journals Cyclic Testing of Concrete-Filled Double-Skin Steel Tubular Column to Steel Beam Joint with RC Slab

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Dongfang Zhang ◽  
Junhai Zhao ◽  
Shuanhai He
Keyword(s):  
Energy Dissipation ◽  
Failure Modes ◽  
Compressive Force ◽  
Steel Beam ◽  
Composite Joints ◽  
Equivalent Viscous Damping ◽  
Rc Slab ◽  
Bare Steel ◽  
Double Skin ◽  
Rc Slabs

The design of composite joints for connecting concrete-filled double-skin tubular (CFDST) columns to steel beams supporting reinforced concrete (RC) slabs is presented in this paper. Five half-scale specimens were designed, including four composite joints with RC slab and one bare steel beam joint, and were tested under a constant axially compressive force and lateral cyclic loading at the top end of the column to evaluate their seismic behavior. The main experimental parameters were the construction of the joint and the type of the column. The seismic behaviors, including the failure modes, hysteresis curves, ductility, strength and stiffness degradation, and energy dissipation, were investigated. The failure modes of the composite joints depended on the joint construction and on the stiffness ratio of beams to columns. Joints of stiffening type had significantly higher load-bearing and deformation capacities than joints of nonstiffening type. Compared with the bare steel beam joint, the bearing capacities of the composite joints with RC slabs were markedly increased. The composite action was remarkable under sagging moments, resulting in larger deformation on the bottom flanges of the beams. Overall, most specimens exhibited full hysteresis loops, and the equivalent viscous damping coefficients were 0.282∼0.311. The interstory drift ratios satisfied the requirements specified by technical regulations. Composite connections of this type exhibit excellent ductility and favorable energy dissipation and can be effectively utilized in superhigh-rise buildings erected in earthquake zones.

Comparison of fatigue resistance and failure modes between metal-ceramic and all-ceramic crowns by cyclic loading in water

2014 ◽  
Vol 42 (12) ◽  
pp. 1613-1620 ◽  
Author(s):  
Maj H. Nicolaisen ◽  
Golnosh Bahrami ◽  
Scott Finlay ◽  
Flemming Isidor
Keyword(s):  
Cyclic Loading ◽  
Fatigue Resistance ◽  
Failure Modes ◽  
All Ceramic ◽  
Metal Ceramic ◽  
Ceramic Crowns

Determination of the Fatigue Behavior of Aluminide Coatings by Means of the Impact Testing Method

2007 ◽  
Vol 348-349 ◽  
pp. 645-648
Author(s):  
Kostas David ◽  
K.G. Anthymidis ◽  
P. Agrianidis ◽  
D.N. Tsipas
Keyword(s):  
Fatigue Failure ◽  
Fatigue Resistance ◽  
Failure Modes ◽  
Impact Load ◽  
Fatigue Behavior ◽  
Impact Testing ◽  
Testing Method ◽  
Aluminide Coatings ◽  
The Impact

The impact testing is an efficient experimental method that enables the quantitative and qualitative determination of the fatigue resistance of mono- and multilayer coatings deposited on various substrates, which was not possible with the common testing methods previously available. In this paper the experimental assessment of the fatigue resistance of coatings working under cyclic loading conditions by means of the dynamic impact testing method is presented. The fatigue failure mode, such cohesive or adhesive, of the investigated coatings is determined using scanning electron and optical microscopy, as well as EDX analysis. Critical values of the stress components, responsible for distinctive fatigue failure modes of the coating substrate system are obtained and the fatigue limits of aluminide coatings are illustrated in simple diagrams containing the impact load versus the number of successive impacts that the examined aluminide-P91 system can withstand.

scholarly journals EVALUATION OF FATIGUE RESISTANCE AND MAINTENANCE METHOD OF RC SLAB WITH THE TOP SURFACE REINFORCED BY OVERLAYING THE SFRC

2011 ◽  
Vol 65 (1) ◽  
pp. 485-492
Author(s):  
Tadashi ABE ◽  
Makiko TAKANO ◽  
Tetsukazu KIDA ◽  
Takayoshi KODAMA
Keyword(s):  
Fatigue Resistance ◽  
Rc Slab

scholarly journals Fatigue Resistance of Y-TZP/Porcelain Crowns is Not Influenced by the Conditioning of the Intaglio Surface

2016 ◽  
Vol 41 (1) ◽  
pp. E1-E12 ◽  
Author(s):  
LC Anami ◽  
JMC Lima ◽  
LF Valandro ◽  
CJ Kleverlaan ◽  
AJ Feilzer ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Failure Modes ◽  
Fracture Initiation ◽  
Nonparametric Test ◽  
Maximum Load ◽  
High Ratio ◽  
Resin Cement ◽  
Adhesive Resin ◽  
Luting Cements ◽  
Adhesive Resin Cement

SUMMARY Objectives The objective of this study was to investigate the effects of treatments of the intaglio surface of Y-TZP frameworks and luting agents on the fatigue resistance of all-ceramic crowns. Methods A research design was chosen that attempted to reduce the likelihood of Hertzian cracking and to increase the probability of fracture initiation at the intaglio surface of the framework. Ninety identical preparations were machined in a dentin-like epoxy composite. Each preparation was restored with a Y-TZP framework made by a CAD/CAM system and veneered using feldspathic ceramic. Prior to cementation the intaglio surface of the ceramic was treated using one of four treatments: 1) cleaning with isopropyl alcohol; 2) application of an overglaze; 3) sandblasting with 125 μm aluminum oxide powder; and 4) sandblasting with 30 μm silica powder (CJ). One of three luting cements were used: 1) zinc phosphate; 2) glass ionomer; and 3) adhesive resin cement (PN). All three cements were tested against frameworks that were alcohol cleaned. Only the PN cements were tested against frameworks that had been sandblasted or glazed. Altogether, six groups of 15 specimens each were tested. Fatigue resistance was evaluated using stepwise loads at 1.4 Hz until failure: 5000 cycles at maximum load of 200 N, followed by 10,000 cycles at maximum loads of 800, 1000, 1200, and 1400 N. The cement thickness and failure modes were analyzed using a stereomicroscope and scanning electron microscopy. The results were analyzed using the Kaplan-Meier and Mantel-Cox log rank tests (5%), a one-way analysis of variance, Tukey multiple comparison test, and Weibull nonparametric test. Results The predominant failure mode was chipping of the veneer. The crowns cemented with the adhesive resin cement exhibited chipping failure at higher mean loads than did crowns cemented with cements that usually do not bond strongly with dentin. When the adhesive cement was used, glazing and sandblasting intaglio framework surface treatments exhibited lower mean loads at chipping than did crowns whose intaglio surface was only cleaned with alcohol. Weibull analysis indicated that all specimens had a high ratio of late-to-early failures. Conclusions The fatigue experiment produced a pattern of failures that is very similar to that observed in clinical trials of Y-TZP crowns that are veneered with feldspathic porcelain. Crowns cemented with an adhesive resin cement exhibited chipping at a significantly higher mean load than those cemented with luting cements that do not usually form strong bonds with dentin. When cemented with adhesive resin cement, glazing or sandblasting the intaglio surface of the framework significantly reduced the mean fatigue loads at which chipping of veneers occurred, as compared to crowns whose intaglio surface had only been cleaned with alcohol. For this cement glazing or sandblasting the intaglio surface of the crown is not recommended.

scholarly journals Influence of internal imperfections on the fatigue resistance of cast steel – testing methodology

2019 ◽  
Vol 300 ◽  
pp. 09001
Author(s):  
Sven Nagel ◽  
Christof Rauber ◽  
Ines Veile ◽  
Peter Knödel ◽  
Thomas Ummenhofer
Keyword(s):  
Fatigue Resistance ◽  
Failure Modes ◽  
Cast Steel ◽  
Internal Defects ◽  
Destructive Testing ◽  
Tensile Fatigue ◽  
Damage Process ◽  
Individual Specimen ◽  
Stress States ◽  
Propagation Properties

Tensile fatigue specimen of G20Mn5 and G22NiMoCr5-6 were tested to quantify the influence of internal defects on the fatigue resistance of cast steel components. Defects with varying sizes, geometric shapes and distribution were enforced by influencing the solidification and recorded by computer tomography (CT). Besides the characteristics of the detected cavities, the surrounding fungoid microstructure is classified and evaluated. Later the specimens were tested under cyclic tension and S/N-curves are derived. These data form the basis for extensive numerical simulations of the damage process and the crack growth of every individual specimen. Both processes are affected by the local multiaxial stress states and have their origin in the inside of the specimen. For validation, knowledge of the crack initiation time and propagation properties are essential. Therefore, all specimens respectively the properties of the internal defects are monitored during testing with three different state-of-the-art non-destructive testing (NDT) methods. Background and application of these NDT techniques are described within this paper. Finally, fracture surface analyses show different failure modes and provide further information for model validation.

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