The Experts below are selected from a list of 52812 Experts worldwide ranked by ideXlab platform
M V Swain - One of the best experts on this subject based on the ideXlab platform.
-
in vitro Strength Degradation of dental ceramics and novel picn material by sharp indentation
Journal of The Mechanical Behavior of Biomedical Materials, 2013Co-Authors: Andrea Coldea, M V Swain, Norbert ThielAbstract:Abstract Objectives To determine the flexural Strength and subsequent Strength Degradation of a range of dental CAD/CAM ceramic materials and novel PICN (Polymer-Infiltrated-Ceramic-Network) materials by means of pre-damaging with Vickers indentations at various loads. Methods The materials tested included (Mark II, PICN test material 1 and 2, In-Ceram Alumina, VM 9, In-Ceram YZ; Vita Zahnfabrik, Bad Saeckingen, Germany) and (IPS e.max CAD, Ivoclar Vivadent, Schaan, Liechtenstein). Bending bars were cut and lapped with 15 µm diamond suspension. Initial flexural Strength ( n =10) was determined in three-point-bending. To evaluate the damage tolerance, Vickers indentations were placed on the bending bars ( n =35) with varying loads (1.96–98.07 N). The indented bending bars were subsequently loaded to fracture in three-point-bending. In addition, the fracture toughness was determined by the indentation Strength (IS) and the SEVNB technique ( n =5). Results With increasing indentation loads the fracture Strength of all materials tested decreased. The material with the highest fracture resistance to indentation induced damage, was the PICN test material 1 with an indentation load-flexural Strength curve slope of 0.21. In-Ceram YZ exhibited the highest damage susceptibility with a slope of 0.4. The fracture toughness varied with the measurement technique and material in the range of 0.82 (VM 9) to 4.94 (In-Ceram YZ) MPa√m for the SEVNB method and 0.96 (VM 9) to 4.97 (In-Ceram YZ) MPa√m for the IS method respectively. Significance This study aims to indicate the likely clinical behavior by evaluating the damage tolerance and R -curve behavior of dental ceramics by in-vitro Strength Degradation and fracture toughness measurements.
-
influence of surface and heat treatments on the flexural Strength of a glass infiltrated alumina zirconia reinforced dental ceramic
Dental Materials, 2005Co-Authors: Massimiliano Guazzato, Mohammad Albakry, Linda Quach, M V SwainAbstract:Summary Objectives The purpose of this study was to investigate the influence of sandblasting, grinding, grinding orientation and polishing before and after heat treatment, on the flexural Strength of a glass-infiltrated alumina/zirconia-reinforced dental ceramic (In-Ceram Zirconia). Methods The uniaxial flexural Strength was calculated on 160bar-shaped specimens (20×4×1.2 mm) divided equally into eight groups as follows: sandblasted; sandblasted heated; polished; polished heated; ground parallel to the tensile axis; ground parallel heated; ground perpendicular; and ground perpendicular heated. Data were analyzed with multiple regression analysis, one-way ANOVA and Tukey's pairwise multiple comparisons and Weibull analysis. The treated and fractured surfaces were observed with SEM. The relative content of the monoclinic phase was quantified with an X-ray diffraction analysis. Results A thin layer of glass was present on the surface of the specimens after heat treatment and contributed to an improvement of the flexural Strength. Surface treatment (not followed by heat treatment) generated phase transformation which, however, was not sufficient to avoid Strength Degradation caused by the flaws introduced with the surface treatments. Sandblasting caused the most marked Strength Degradation. Polishing alone increased the reliability, but did not improve the Strength. The orientation of grinding in respect of the direction of the tensile stresses did not influence the ultimate tensile Strength. Significance The present study suggests that any surface treatment performed on In-Ceram Zirconia should always be followed by heat treatment to avoid Strength Degradation.
-
influence of grinding sandblasting polishing and heat treatment on the flexural Strength of a glass infiltrated alumina reinforced dental ceramic
Biomaterials, 2004Co-Authors: Massimiliano Guazzato, Mohammad Albakry, Linda Quach, M V SwainAbstract:The influence of processing-introduced flaws and heat treatment on the Strength Degradation of the dental core material has recently been observed. However, there are insufficient studies which investigate the role of grinding, grinding orientation, sandblasting, polishing and heat treatment on the Strength of In-Ceram Alumina (IA), one of the most used glass-infiltrated alumina-reinforced dental core ceramics. To address these issues, the uniaxial flexural Strength and reliability of eight groups of specimens (sandblasted, ground parallel to the tensile axis, ground perpendicular, and polished with and without heat treatment) were assessed. Statistical analyses indicate that heat treatment significantly improved the flexural Strength of the material regardless of the surface treatment. Conversely, any surface treatment caused Strength Degradation, if it was not followed by heat treatment. Sandblasting caused the most marked Strength Degradation. Polishing alone (without heat treatment) did not Strengthen the ceramic. The orientation of grinding in respect of the direction of the tensile stresses did not influence the ultimate tensile Strength. The present study suggests that, in the case of IA, sandblasting, grinding and polishing should always be followed by heat treatment in order to avoid Strength Degradation of the material.
-
interrelation among flaw resistance kr curve behavior and thermal shock Strength Degradation in ceramics i theoretical considerations
Journal of The European Ceramic Society, 1991Co-Authors: H E Lutz, M V SwainAbstract:Abstract This paper presents a new concept by which both the K R -curve behavior and thermal shock Strength Degradation of a ceramic material can be predicted simultaneously by applying the ‘Vickers Indentation Strength in Bending (ISB)’ method.
Li Longbiao - One of the best experts on this subject based on the ideXlab platform.
-
Modeling Strength Degradation of Fiber-Reinforced Ceramic-Matrix Composites Subjected to Cyclic Loading at Elevated Temperatures in Oxidative Environments
Applied Composite Materials, 2017Co-Authors: Li LongbiaoAbstract:In this paper, the Strength Degradation of non-oxide and oxide/oxide fiber-reinforced ceramic-matrix composites (CMCs) subjected to cyclic loading at elevated temperatures in oxidative environments has been investigated. Considering damage mechanisms of matrix cracking, interface debonding, interface wear, interface oxidation and fibers fracture, the composite residual Strength model has been established by combining the micro stress field of the damaged composites, the damage models, and the fracture criterion. The relationships between the composite residual Strength, fatigue peak stress, interface debonding, fibers failure and cycle number have been established. The effects of peak stress level, initial and steady-state interface shear stress, fiber Weibull modulus and fiber Strength, and testing temperature on the Degradation of composite Strength and fibers failure have been investigated. The evolution of residual Strength versus cycle number curves of non-oxide and oxide/oxide CMCs under cyclic loading at elevated temperatures in oxidative environments have been predicted.
-
Modeling Strength Degradation of fiber-reinforced ceramic-matrix composites under cyclic loading at room and elevated temperatures
Materials Science and Engineering: A, 2017Co-Authors: Li LongbiaoAbstract:Abstract In this paper, the Strength Degradation of fiber-reinforced ceramic-matrix composites (CMCs) under cyclic loading at room and elevated temperatures has been investigated. The shear-lag model combined with the matrix statistical multiple cracking model, interface debonding criterion and fiber fracture model has been adopted to analyze the stress distributions in damaged CMCs, considering the damage mechanism of the interface wear. The relationships between the residual Strength and peak stress, interface debonding, fiber failure and cycle number have been established. The effects of fatigue peak stress, initial and steady-state interface shear stress, fiber Weibull modulus and fiber Strength on the Degradation of residual Strength and fibers failure have been investigated. The evolution of residual Strength versus cycle number curves of fiber-reinforced CMCs under cyclic loading at room and elevated temperatures have been predicted.
M Arabnejad M Khanouki - One of the best experts on this subject based on the ideXlab platform.
-
experimental assessment of angle shear connectors under monotonic and fully reversed cyclic loading in high Strength concrete
Construction and Building Materials, 2014Co-Authors: Ali Shariati, Mahdi Shariati, N Ramli H Sulong, Meldi Suhatril, M Arabnejad M Khanouki, Mehrdad MahoutianAbstract:Abstract An experimental study was performed to investigate the behaviour of angle shear connectors embedded in high Strength concrete (HSC) slab. Eight push-out specimens were tested covering various geometries of angle shear connector. On top of the experimental study, the accuracy of the available equations to estimate the load capacities of angle connectors is also evaluated for the angles embedded in HSC. The results show inadequate ductility behaviour for the angle shear connectors embedded in HSC. Nonetheless, the angle connectors exhibited good behaviour in the case of Strength Degradation under cyclic loading. All specimens experienced the angle fracture type of failure and showed a very low Strength Degradation (0.1%–1.4%) when they were subjected to low cyclic fatigue loading. This study also concludes that the current available equations estimated the shear capacity of angle connectors embedded in HSC either are conservative or overestimate the ultimate capacity.
-
behaviour of c shaped angle shear connectors under monotonic and fully reversed cyclic loading an experimental study
Materials & Design, 2012Co-Authors: Mahdi Shariati, Ali Shariati, N Ramli H Sulong, Meldi Suhatril, M Arabnejad M Khanouki, Hamid SinaeiAbstract:Abstract This paper presents an evaluation of the structural behaviour of C-shaped angle shear connectors in composite beams, suitable for transferring shear force in composite structures. The results of the experimental programme, including eight push-out tests, are presented and discussed. The results include resistance, Strength Degradation, ductility, and failure modes of C-shaped angle shear connectors, under monotonic and fully reversed cyclic loading. The results show that connector fracture type of failure was experienced in C-shaped angle connectors and after the failure, more cracking was observed in those slabs with longer angles. On top of that, by comparing the shear resistance of C-shaped angle shear connectors under monotonic and cyclic loading, these connectors showed 8.8–33.1% Strength Degradation, under fully reversed cyclic loading. Furthermore, it was concluded that the mentioned shear connector shows a proper behaviour, in terms of the ultimate shear capacity, but it does not satisfy the ductility criteria, imposed by the Eurocode 4, to perform a plastic distribution of the shear force between different connectors along the beam length.
-
experimental assessment of channel shear connectors under monotonic and fully reversed cyclic loading in high Strength concrete
Materials & Design, 2012Co-Authors: Mahdi Shariati, N Ramli H Sulong, M Arabnejad M KhanoukiAbstract:An experimental study was performed to investigate the behaviour of angle shear connectors embedded in high Strength concrete (HSC) slab. Eight push-out specimens were tested covering various geometries of angle shear connector. On top of the experimental study, the accuracy of the available equations to estimate the load capacities of angle connectors is also evaluated for the angles embedded in HSC. The results show inadequate ductility behaviour for the angle shear connectors embedded in HSC. Nonetheless, the angle connectors exhibited good behaviour in the case of Strength Degradation under cyclic loading. All specimens experienced the angle fracture type of failure and showed a very low Strength Degradation (0.1%–1.4%) when they were subjected to low cyclic fatigue loading. This study also concludes that the current available equations estimated the shear capacity of angle connectors embedded in HSC either are conservative or overestimate the ultimate capacity.
Mahdi Shariati - One of the best experts on this subject based on the ideXlab platform.
-
experimental assessment of angle shear connectors under monotonic and fully reversed cyclic loading in high Strength concrete
Construction and Building Materials, 2014Co-Authors: Ali Shariati, Mahdi Shariati, N Ramli H Sulong, Meldi Suhatril, M Arabnejad M Khanouki, Mehrdad MahoutianAbstract:Abstract An experimental study was performed to investigate the behaviour of angle shear connectors embedded in high Strength concrete (HSC) slab. Eight push-out specimens were tested covering various geometries of angle shear connector. On top of the experimental study, the accuracy of the available equations to estimate the load capacities of angle connectors is also evaluated for the angles embedded in HSC. The results show inadequate ductility behaviour for the angle shear connectors embedded in HSC. Nonetheless, the angle connectors exhibited good behaviour in the case of Strength Degradation under cyclic loading. All specimens experienced the angle fracture type of failure and showed a very low Strength Degradation (0.1%–1.4%) when they were subjected to low cyclic fatigue loading. This study also concludes that the current available equations estimated the shear capacity of angle connectors embedded in HSC either are conservative or overestimate the ultimate capacity.
-
behaviour of c shaped angle shear connectors under monotonic and fully reversed cyclic loading an experimental study
Materials & Design, 2012Co-Authors: Mahdi Shariati, Ali Shariati, N Ramli H Sulong, Meldi Suhatril, M Arabnejad M Khanouki, Hamid SinaeiAbstract:Abstract This paper presents an evaluation of the structural behaviour of C-shaped angle shear connectors in composite beams, suitable for transferring shear force in composite structures. The results of the experimental programme, including eight push-out tests, are presented and discussed. The results include resistance, Strength Degradation, ductility, and failure modes of C-shaped angle shear connectors, under monotonic and fully reversed cyclic loading. The results show that connector fracture type of failure was experienced in C-shaped angle connectors and after the failure, more cracking was observed in those slabs with longer angles. On top of that, by comparing the shear resistance of C-shaped angle shear connectors under monotonic and cyclic loading, these connectors showed 8.8–33.1% Strength Degradation, under fully reversed cyclic loading. Furthermore, it was concluded that the mentioned shear connector shows a proper behaviour, in terms of the ultimate shear capacity, but it does not satisfy the ductility criteria, imposed by the Eurocode 4, to perform a plastic distribution of the shear force between different connectors along the beam length.
-
experimental assessment of channel shear connectors under monotonic and fully reversed cyclic loading in high Strength concrete
Materials & Design, 2012Co-Authors: Mahdi Shariati, N Ramli H Sulong, M Arabnejad M KhanoukiAbstract:An experimental study was performed to investigate the behaviour of angle shear connectors embedded in high Strength concrete (HSC) slab. Eight push-out specimens were tested covering various geometries of angle shear connector. On top of the experimental study, the accuracy of the available equations to estimate the load capacities of angle connectors is also evaluated for the angles embedded in HSC. The results show inadequate ductility behaviour for the angle shear connectors embedded in HSC. Nonetheless, the angle connectors exhibited good behaviour in the case of Strength Degradation under cyclic loading. All specimens experienced the angle fracture type of failure and showed a very low Strength Degradation (0.1%–1.4%) when they were subjected to low cyclic fatigue loading. This study also concludes that the current available equations estimated the shear capacity of angle connectors embedded in HSC either are conservative or overestimate the ultimate capacity.
N Ramli H Sulong - One of the best experts on this subject based on the ideXlab platform.
-
experimental assessment of angle shear connectors under monotonic and fully reversed cyclic loading in high Strength concrete
Construction and Building Materials, 2014Co-Authors: Ali Shariati, Mahdi Shariati, N Ramli H Sulong, Meldi Suhatril, M Arabnejad M Khanouki, Mehrdad MahoutianAbstract:Abstract An experimental study was performed to investigate the behaviour of angle shear connectors embedded in high Strength concrete (HSC) slab. Eight push-out specimens were tested covering various geometries of angle shear connector. On top of the experimental study, the accuracy of the available equations to estimate the load capacities of angle connectors is also evaluated for the angles embedded in HSC. The results show inadequate ductility behaviour for the angle shear connectors embedded in HSC. Nonetheless, the angle connectors exhibited good behaviour in the case of Strength Degradation under cyclic loading. All specimens experienced the angle fracture type of failure and showed a very low Strength Degradation (0.1%–1.4%) when they were subjected to low cyclic fatigue loading. This study also concludes that the current available equations estimated the shear capacity of angle connectors embedded in HSC either are conservative or overestimate the ultimate capacity.
-
behaviour of c shaped angle shear connectors under monotonic and fully reversed cyclic loading an experimental study
Materials & Design, 2012Co-Authors: Mahdi Shariati, Ali Shariati, N Ramli H Sulong, Meldi Suhatril, M Arabnejad M Khanouki, Hamid SinaeiAbstract:Abstract This paper presents an evaluation of the structural behaviour of C-shaped angle shear connectors in composite beams, suitable for transferring shear force in composite structures. The results of the experimental programme, including eight push-out tests, are presented and discussed. The results include resistance, Strength Degradation, ductility, and failure modes of C-shaped angle shear connectors, under monotonic and fully reversed cyclic loading. The results show that connector fracture type of failure was experienced in C-shaped angle connectors and after the failure, more cracking was observed in those slabs with longer angles. On top of that, by comparing the shear resistance of C-shaped angle shear connectors under monotonic and cyclic loading, these connectors showed 8.8–33.1% Strength Degradation, under fully reversed cyclic loading. Furthermore, it was concluded that the mentioned shear connector shows a proper behaviour, in terms of the ultimate shear capacity, but it does not satisfy the ductility criteria, imposed by the Eurocode 4, to perform a plastic distribution of the shear force between different connectors along the beam length.
-
experimental assessment of channel shear connectors under monotonic and fully reversed cyclic loading in high Strength concrete
Materials & Design, 2012Co-Authors: Mahdi Shariati, N Ramli H Sulong, M Arabnejad M KhanoukiAbstract:An experimental study was performed to investigate the behaviour of angle shear connectors embedded in high Strength concrete (HSC) slab. Eight push-out specimens were tested covering various geometries of angle shear connector. On top of the experimental study, the accuracy of the available equations to estimate the load capacities of angle connectors is also evaluated for the angles embedded in HSC. The results show inadequate ductility behaviour for the angle shear connectors embedded in HSC. Nonetheless, the angle connectors exhibited good behaviour in the case of Strength Degradation under cyclic loading. All specimens experienced the angle fracture type of failure and showed a very low Strength Degradation (0.1%–1.4%) when they were subjected to low cyclic fatigue loading. This study also concludes that the current available equations estimated the shear capacity of angle connectors embedded in HSC either are conservative or overestimate the ultimate capacity.
