Numerical Modeling of the Fracture Process of a Three-Unit All-Ceramic Fixed Partial Denture

2010 ◽  
Vol 97-101 ◽  
pp. 1569-1572
Author(s):  
Cheng Fan ◽  
Li Chi Han
Keyword(s):  
Numerical Modeling ◽  
Fracture Mechanism ◽  
Fracture Process ◽  
Lower Boundary ◽  
Fracture Pattern ◽  
Tensile Failure ◽  
Zirconia Ceramic ◽  
Fracture Mechanisms ◽  
All Ceramic ◽  
Modeling Code

Fracture of dental all-ceramic restoration is often observed in clinic. And the fracture mechanisms and processes of three-unit all-ceramic fixed partial dentures (FPDs) are still not clear. In this paper, the fracture mechanism and process of a three unit zirconia ceramic FPDs framework under simulated mechanical loading are calculated by using a self-developed numerical modeling code, the RFPA2D code. Acoustic emission showed that the fracture mechanism was tensile failure and the crack started at the lower boundary of the framework. The result revealed that the framework fracture pattern obtained by using the numerical simulation agreed with that observed in a previous laboratory test. The fracture process could be followed both in step-by-step and step-in-step. The RFPA2D code is suitable for the use as a complement to other tests and clinical observations in studying stress distribution, fracture mechanism and fracture process in ceramic FPDs framework.

Numerical modeling of the fracture process in a three-unit all-ceramic fixed partial denture

2007 ◽  
Vol 23 (8) ◽  
pp. 1042-1049 ◽  
Author(s):  
Wen Kou ◽  
Shaoquan Kou ◽  
Hongyuan Liu ◽  
Göran Sjögren
Keyword(s):  
Numerical Modeling ◽  
Fracture Process ◽  
Partial Denture ◽  
Fixed Partial Denture ◽  
All Ceramic

scholarly journals Repair Bond Strength of Composite to Zirconia Ceramic Using Two Types of Zirconia Primers

2020 ◽  
Author(s):  
Hoseinali Mahgoli ◽  
Mahnaz Arshad ◽  
Kamran Rasouli ◽  
Ali Akbar Sobati ◽  
Ahmad Reza Shamshiri
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Composite Resin ◽  
Zirconia Ceramic ◽  
Adhesive Failure ◽  
Cohesive Failure ◽  
Simultaneous Application ◽  
All Ceramic ◽  
The Mean

  Objectives: This study aimed to assess the effect of application of two types of zirconia primers on repair bond strength of composite to zirconia ceramic. Materials and Methods: In this in vitro, experimental study, 60 zirconia blocks were divided into five groups and subjected to the application of Z-Prime Plus (ZPP), Monobond Plus (MBP), Porcelain Bonding Resin (PBR), ZPP followed by PBR (ZPP+PBR) and MBP followed by PBR (MBP+PBR). They were then bonded to Z100 composite. The samples were then immersed in water at 37°C for 24 hours, thermocycled for 1000 cycles between 5-55°C and subjected to shear bond strength (SBS) test. The mode of failure was determined under a stereomicroscope and a scanning electron microscope (SEM). Results: The mean bond strength was the highest in ZPP+PBR group followed by MBP+PBR, ZPP, PBR and MBP group (22.29±8.86, 15.75±2.81, 12.02±3.24, 3.60±2.92 and 2.92±1.78 MPa, respectively). The effects of type of zirconia primer and use/no use of PBR on SBS were significant (P<0.05). The frequency of adhesive failure in MBP and PBR groups was significantly higher than that in MBP+PBR and ZPP+PBR groups (P<0.05). The cohesive failure was significantly more frequent in ZPP+PBR group than in ZPP, MBP and PBR groups (P<0.05). Conclusion: Simultaneous application of zirconia primer and PBR is the most efficient technique for repair of all-ceramic zirconia restorations with composite resin.

A review on experimental and numerical investigations of cortical bone fracture

2022 ◽  
pp. 095441192110703
Author(s):  
Ajay Kumar ◽  
Rajesh Ghosh
Keyword(s):  
Fracture Toughness ◽  
Cortical Bone ◽  
Bone Fracture ◽  
Bone Fractures ◽  
Complete Information ◽  
Fracture Pattern ◽  
Future Research ◽  
Fracture Mechanisms ◽  
Numerical Investigations ◽  
Fracture Parameters

This paper comprehensively reviews the various experimental and numerical techniques, which were considered to determine the fracture characteristics of the cortical bone. This study also provides some recommendations along with the critical review, which would be beneficial for future research of fracture analysis of cortical bone. Cortical bone fractures due to sports activities, climbing, running, and engagement in transport or industrial accidents. Individuals having different diseases are also at high risk of cortical bone fracture. It has been observed that osteon orientation influences cortical bone fracture toughness and fracture mechanisms. Apart from this, recent studies indicate that fracture parameters of cortical bone also depend on many factors such as age, sex, temperature, osteoporosis, orientation, location, loading condition, strain rate, and storage facility, etc. The cortical bone regains its fracture toughness due to various toughening mechanisms. Owing to these factors, several experimental, clinical, and numerical investigations have been carried out to determine the fracture parameters of the cortical bone. Cortical bone is the dense outer surface of the bone and contributes to 80%–82% of the skeleton mass. Cortical bone experiences load far exceeding body weight due to muscle contraction and the dynamics of motion. It is very important to know the fracture pattern, direction of fracture, location of the fracture, and toughening mechanism of cortical bone. A basic understanding of the different factors that affect the fracture parameters and fracture mechanisms of the cortical bone is necessary to prevent the failure and fracture of cortical bone. This review has summarized the advancement considered in the various experimental techniques and numerical methods to get complete information about the fracture mechanisms of cortical bone.

Fracture Mechanism and Fracture Toughness at the Interface Between Cortical and Cancellous Bone

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Pankaj Shitole ◽  
Arpan Gupta ◽  
Rajesh Ghosh
Keyword(s):  
Fracture Toughness ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Fracture Mechanism ◽  
Fracture Mechanisms ◽  
J Integral ◽  
Single Edge ◽  
Plastic Part ◽  
Edge Notch ◽  
Sample Width

The microstructure at the interface of cortical and cancellous bone is quite complicated. The fracture mechanisms at this location are necessary for understanding the comprehensive fracture of the whole bone. The goal of this study is to identify fracture toughness in terms of J integral and fracture mechanism at the interface between cortical and cancellous bone. For this purpose, single edge notch bend (SENB) specimens were prepared from bovine proximal femur according to ASTM-E399 standard. Bone samples were prepared such that half of the sample width consists of cortical bone and other half of the width was cancellous bone; this interfacial bone is referred as a corticellous bone. Elastic–plastic fracture mechanics was used to measure fracture toughness. The J integral (both elastic and plastic) was used to quantify the fracture toughness. The plastic part of J integral value (Jpl) of corticellous specimen was 9310 J m−2, and shown to be 27 times of the J integral of the elastic part (Jel), 341 J m−2. The total J integral of the corticellous bone was found to be 9651 J m−2, which is close to two times of the cortical bone, 4731 J m−2. This study observed that J integral of corticellous bone is higher than the cortical bone since more energy is required for plastic deformation of corticellous bone due to crack branches and slowdown at the interface between cortical and cancellous bone.

scholarly journals Tensile Fracture Mechanism of Masonry Wallettes Parallel to Bed Joints: A Stochastic Discontinuum Analysis

Modelling ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 78-93
Author(s):  
Bora Pulatsu ◽  
Semih Gonen ◽  
Ece Erdogmus ◽  
Paulo B. Lourenço ◽  
Jose V. Lemos ◽  
...  
Keyword(s):  
Material Properties ◽  
Fracture Mechanism ◽  
Equations Of Motion ◽  
Constitutive Models ◽  
Numerical Approach ◽  
Tensile Fracture ◽  
Fracture Mechanisms ◽  
Contact Points ◽  
Statistical Variations ◽  
Modeling Strategy

Nonhomogeneous material characteristics of masonry lead to complex fracture mechanisms, which require substantial analysis regarding the influence of masonry constituents. In this context, this study presents a discontinuum modeling strategy, based on the discrete element method, developed to investigate the tensile fracture mechanism of masonry wallettes parallel to the bed joints considering the inherent variation in the material properties. The applied numerical approach utilizes polyhedral blocks to represent masonry and integrate the equations of motion explicitly to compute nodal velocities for each block in the system. The mechanical interaction between the adjacent blocks is computed at the active contact points, where the contact stresses are calculated and updated based on the implemented contact constitutive models. In this research, different fracture mechanisms of masonry wallettes under tension are explored developing at the unit–mortar interface and/or within the units. The contact properties are determined based on certain statistical variations. Emphasis is given to the influence of the material properties on the fracture mechanism and capacity of the masonry assemblages. The results of the analysis reveal and quantify the importance of the contact properties for unit and unit–mortar interfaces (e.g., tensile strength, cohesion, and friction coefficient) in terms of capacity and corresponding fracture mechanism for masonry wallettes.

The Effect of Ceramic Surface Treatments on the Shear Bond Strength of Dental Composite Resin to All-Ceramic Coping Materials

2007 ◽  
Vol 330-332 ◽  
pp. 1365-1368
Author(s):  
W.H. Kim ◽  
H.J. Lee ◽  
Keun Woo Lee ◽  
Kwang Mahn Kim ◽  
Kyoung Nam Kim ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Composite Resin ◽  
Silica Coating ◽  
Surface Treatments ◽  
Dental Composite ◽  
Zirconia Ceramic ◽  
Ceramic Surface ◽  
All Ceramic ◽  
Alumina Particles

The purpose of this study was to evaluate the shear bond strength of composite resin to 4 different all-ceramic coping materials with 3 different surface treatments after thermocycling and without thermocycling. Three different surface treatments - sandblasting with 50 ㎛ alumina particles (AB); sandblasting with 50 ㎛ alumina particles and acid etching with 4% hydrofluoric acid (AE); sandblasting with 50 ㎛ alumina particles and 30 ㎛ alumina particles with tribochemical silica coating (SI) and silane application - were used on four different all-ceramic; Feldspatic ceramic (Duceram Plus); Lithium disilicate ceramic (IPS Empress2); Alumica ceramic (In-Ceram Alumina); Zirconia ceramic (Zi-Ceram) - substrates. Shear bond strength of restorative composite resin to substrate was tested after thermocycling and without thermocycling (n=10). Each specimen was subjected to a shear load at a crosshead speed of 2 ㎜/min until fracture. Two-way analysis of variance and Duncan multiple comparison test (α =0.05) were used to analyze the bond strength values. There were significant differences in the bond strengths for ceramic types (P<.001), surface treatments (P<.001), and thermocycling (P<.001). The Duncan analysis showed that the Si specimens had significantly higher bonding strengths than other specimens. The bond strength of composite resin decreased after thermocycling.

Behavior and Fracture Mechanism of Brittle Rock with Pre-Existing Parallel Cracks

2006 ◽  
Vol 324-325 ◽  
pp. 1055-1058 ◽  
Author(s):  
M.X. Zhang ◽  
X.L. Lee ◽  
A.A. Javadi
Keyword(s):  
Fracture Mechanism ◽  
Rock Fracture ◽  
Strength Criterion ◽  
Brittle Rock ◽  
Fracture Mechanisms ◽  
Stress Equilibrium ◽  
Parallel Cracks ◽  
Micro Cracks ◽  
Griffith Theory ◽  
Almost All

There is a macro-crack and micro-crack system in rock, which affects almost all the mechanical properties of rock, especially for the fracture mechanism. The propagation of pre-existing cracks in rock samples under load is fundamental to understanding of rock fracture mechanisms. It is evident that assumption of Griffith theory was not in accord with the fact that numerous cracks exist in rock. So, it is difficult to explain how the propagation of a micro-crack developed into macro-failure by conventional theories. In order to investigate the cause and results of fracture within the rock, the stress concentration around the micro-cracks was analyzed, which resulted in propagation of wing cracks and connecting adjacent original cracks, eventually leading to macro-failure. The experiments on gypseous samples with pre-existing parallel cracks (flat rectangular in shape) under compression were carried out. The fracture mechanism and the stress equilibrium condition at brittle rock were discussed. Based on the fracture mechanism of brittle rock, a strength criterion of rock was proposed.

Research Progress on Fracture Mechanism of Mechanical Products

2010 ◽  
Vol 118-120 ◽  
pp. 551-555
Author(s):  
Jiang Shao ◽  
Cheng Hui Zeng
Keyword(s):  
Ductile Fracture ◽  
Failure Mechanism ◽  
Fatigue Fracture ◽  
Cleavage Fracture ◽  
Fracture Mechanism ◽  
Research Progress ◽  
Fracture Mechanisms ◽  
Reliability Design ◽  
Mechanical Products

Based on reliability physics theory, investigation on failure mechanism is a kernel job in reliability design and analysis of mechanical products. The basic conception and classification of failure mechanism are introduced. Researches on five kinds of fracture mechanisms (ductile fracture, cleavage fracture, quasi-cleavage fracture, fatigue fracture and intergranular fracture) are discussed in detail. At last, problems are summarized and suggestions for future investigations are also made.

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