A new three-dimensional interface (contact) element for fiber pull-out behavior in composites

1992 ◽  
Vol 44 (4) ◽  
pp. 753-764 ◽  
Author(s):  
Mallikarjuna M. Fafard ◽  
N. Banthia
Keyword(s):  
Three Dimensional ◽  
Contact Element ◽  
Pull Out ◽  
Interface Contact

scholarly journals Experimental & FEM Analysis of Orthodontic Mini-Implant Design on Primary Stability

2021 ◽  
Vol 11 (12) ◽  
pp. 5461
Author(s):  
Elmedin Mešić ◽  
Enis Muratović ◽  
Lejla Redžepagić-Vražalica ◽  
Nedim Pervan ◽  
Adis J. Muminović ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Primary Stability ◽  
Fem Analysis ◽  
Implant Design ◽  
Special Focus ◽  
Engineering System ◽  
Mini Implants ◽  
Pull Out ◽  
Computer Aided

The main objective of this research is to establish a connection between orthodontic mini-implant design, pull-out force and primary stability by comparing two commercial mini-implants or temporary anchorage devices, Tomas®-pin and Perfect Anchor. Mini-implant geometric analysis and quantification of bone characteristics are performed, whereupon experimental in vitro pull-out test is conducted. With the use of the CATIA (Computer Aided Three-dimensional Interactive Application) CAD (Computer Aided Design)/CAM (Computer Aided Manufacturing)/CAE (Computer Aided Engineering) system, 3D (Three-dimensional) geometric models of mini-implants and bone segments are created. Afterwards, those same models are imported into Abaqus software, where finite element models are generated with a special focus on material properties, boundary conditions and interactions. FEM (Finite Element Method) analysis is used to simulate the pull-out test. Then, the results of the structural analysis are compared with the experimental results. The FEM analysis results contain information about maximum stresses on implant–bone system caused due to the pull-out force. It is determined that the core diameter of a screw thread and conicity are the main factors of the mini-implant design that have a direct impact on primary stability. Additionally, stresses generated on the Tomas®-pin model are lower than stresses on Perfect Anchor, even though Tomas®-pin endures greater pull-out forces, the implant system with implemented Tomas®-pin still represents a more stressed system due to the uniform distribution of stresses with bigger values.

A Nonlinear Rail Vehicle Dynamics Computer Program SAMS/Rail: Part 1—Theory and Formulations

2009 ◽  
Author(s):  
Khaled E. Zaazaa ◽  
Brian Whitten ◽  
Brian Marquis ◽  
Erik Curtis ◽  
Magdy El-Sibaie ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Contact Element ◽  
Contact Forces ◽  
Simulation Code ◽  
Vehicle Performance ◽  
Normal Contact ◽  
Advantages And Disadvantages ◽  
High Speed Trains

Accurate prediction of railroad vehicle performance requires detailed formulations of wheel-rail contact models. In the past, most dynamic simulation tools used an offline wheel-rail contact element based on look-up tables that are used by the main simulation solver. Nowadays, the use of an online nonlinear three-dimensional wheel-rail contact element is necessary in order to accurately predict the dynamic performance of high speed trains. Recently, the Federal Railroad Administration, Office of Research and Development has sponsored a project to develop a general multibody simulation code that uses an online nonlinear three-dimensional wheel-rail contact element to predict the contact forces between wheel and rail. In this paper, several nonlinear wheel-rail contact formulations are presented, each using the online three-dimensional approach. The methods presented are divided into two contact approaches. In the first Constraint Approach, the wheel is assumed to remain in contact with the rail. In this approach, the normal contact forces are determined by using the technique of Lagrange multipliers. In the second Elastic Approach, wheel/rail separation and penetration are allowed, and the normal contact forces are determined by using Hertz’s Theory. The advantages and disadvantages of each method are presented in this paper. In addition, this paper discusses future developments and improvements for the multibody system code. Some of these improvements are currently being implemented by the University of Illinois at Chicago (UIC). In the accompanying “Part 2” and “Part 3” to this paper, numerical examples are presented in order to demonstrate the results obtained from this research.

Study on Conductive Mechanism of Carbon Fiber Filled Cement-Based Composites

2011 ◽  
Vol 415-417 ◽  
pp. 1435-1438
Author(s):  
Xue Li Nan ◽  
Xiao Min Li
Keyword(s):  
Electrical Resistivity ◽  
Carbon Fiber ◽  
Cement Paste ◽  
Ionic Conduction ◽  
Strong Electrolyte ◽  
Pull Out ◽  
Fiber Bridging ◽  
Interface Contact ◽  
Conductive Mechanism ◽  
Conductive Properties

In order to investigate conductive mechanism of carbon fiber filled cement-based composites, the conductive properties of cement paste, carbon fiber filled cement-based composites containing different contents of carbon fibers or aggregates were studied. Experimental results indicate that the electrical resistance of the plain cement paste obviously increases with hydration time, which results from the ionic conduction in strong electrolyte solution. The electrical resistivity of the carbon fiber filled cement-based composites decreases with the increase of fiber content. Both contacting conduction and ionic conduction are in charge of the electrical conduction in these composites. The electrical resistivity of the carbon fiber filled cement-based composites decreases under compression, which is due to the improvement of interface contact between matrix and fibers and the increase of fiber bridging probability. The fiber pull-out and breaking under tension lead to an increase in electrical resistivity of these composites. Aggregates block fiber dispersion and contact. This causes an increase in electrical resistivity of the composites.

scholarly journals PIP Preparation of Silica Fibre Fabric Reinforced Silicon Nitride-Based Composites using Polyhydridomethylsilazane

2005 ◽  
Vol 14 (4) ◽  
pp. 096369350501400
Author(s):  
Gong-jin Qi ◽  
Chang-rui Zhang ◽  
Hai-feng Hu ◽  
Chang-cheng Zhou
Keyword(s):  
Mechanical Property ◽  
Silicon Nitride ◽  
Three Dimensional ◽  
Matrix Interface ◽  
Interface Bonding ◽  
Pull Out ◽  
New Type ◽  
Ammonia Atmosphere ◽  
Fibre Matrix ◽  
Silica Fibre

A new type of composites, three-dimensional silica fibre fabric reinforced silicon nitride-based composites, were prepared by PIP method through repeated infiltration of polyhydridomethylsilazane and pyrolysis at 773-873K in ammonia atmosphere. The density of the composites reached 1.66g/cm3 after four PIP cycles, and the flexural strength was 56.3 MPa. The composites showed a near-brittle fracture mode without long fibre pull-out in the fracture surface. It was the relatively strong fibre/matrix interface bonding that led to the moderate mechanical property.

scholarly journals Bonding Performance and Evaluation of Basalt Fiber Asphalt Macadam Seal

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Enmao Quan ◽  
Yangsen Cao ◽  
Hongke Xu
Keyword(s):  
Shear Strength ◽  
Asphalt Pavement ◽  
Three Dimensional ◽  
Basalt Fiber ◽  
Strengthening Mechanism ◽  
Economic Benefits ◽  
Bonding Performance ◽  
Pull Out ◽  
Comprehensive Performance ◽  
Emulsified Asphalt

To broaden the application of the basalt fiber in the preventive maintenance of asphalt pavement, this study investigated the bonding performance and evaluated the comprehensive performance of the basalt fiber asphalt macadam seal. Firstly, different types of basalt fiber asphalt macadam seal were prepared. The influences of content and length of the basalt fiber and dosage of emulsified asphalt on the bonding performance of the asphalt macadam seal were analyzed and compared. Next, by using the efficacy coefficient method, comprehensive performance considering both mechanical and economic characteristics of the basalt fiber asphalt macadam seal was evaluated. After that, reasonable content of each material was determined. Finally, the strengthening mechanism of the fiber on the bonding performance of macadam seals was revealed from a microscopic view. The results showed that compared with the ordinary asphalt macadam seal, the loss aggregate rate of the basalt fiber asphalt macadam seal was 11.0–30.5% lower, and the pull-out strength, shear strength, and torsional shear strength were 11.7–16.3%, 9.7–22.4%, and 4.2–20.6% higher, respectively. Considering the bonding performance and economic benefits, the optimal amount of emulsified asphalt and basalt fiber was 1.6 kg/m2 and 70 g/m2, respectively. Basalt fiber increased the cohesion of the asphalt material and improved the bonding performance of asphalt macadam seals through formation of the three-dimensional network structure. This study can provide reference to the application of basalt fibers in asphalt pavement maintenance.

Reliability Study of the Hydraulically Expanded Tube-to-Tubesheet Joint

2005 ◽  
Vol 128 (3) ◽  
pp. 408-413 ◽  
Author(s):  
Caifu Qian ◽  
Chenghong Duan ◽  
Hongjie Yu ◽  
Hongwei Duan ◽  
Junli Tian
Keyword(s):  
Finite Element ◽  
Contact Surface ◽  
Three Dimensional ◽  
Element Model ◽  
Tube Sheet ◽  
Reliability Study ◽  
Pull Out ◽  
Finite Element Calculations ◽  
Grooved Tube ◽  
Contact Pressures

A three-dimensional parametrized finite element model is established for the nonlinear analysis of the hydraulically expanded tube-to-tubesheet joint. Distribution of the residual contact pressure on the contact surface between the tube and the tubesheet is investigated. It is found that sealing circular bands exist on the contact surface which enhance the sealing of the joint since the residual contact pressures on the sealing circular bands are higher than on other positions. The sealing circular bands are located close to the two ends of the hole when it is not grooved, but they are located at the two brinks of the groove for a grooved hole and in the latter case, the residual contact pressures are even higher, reflecting that the joint with a grooved tube-sheet hole is more capable of sealing. Experiments and finite element calculations for the pull-out force of the joint are also performed for different expansion pressures and groove widths. Results show that with the increase of the groove width, the measured pull-out force increases significantly and becomes larger and larger than the calculated one, which is owing to the scratch on the contact surface between the tube and tubesheet.

scholarly journals Performance Analysis of Conical Permanent Magnet Couplings for Underwater Propulsion

2019 ◽  
Vol 7 (6) ◽  
pp. 187 ◽  
Author(s):  
Li ◽  
Hu ◽  
Song ◽  
Mao ◽  
Tian
Keyword(s):  
Finite Element ◽  
Permanent Magnet ◽  
Cone Angle ◽  
Three Dimensional ◽  
Design Parameters ◽  
3D Fem ◽  
Torque Density ◽  
Design And Optimization ◽  
Pull Out ◽  
Underwater Propulsion

Permanent magnet couplings (PMCs) are widely used in underwater propulsion because it can solve the deep-sea sealing problem effectively. In this paper, a new type of conical permanent magnet coupling (CPMC) is proposed, which is able to match the tail shape of the underwater vehicle and make full use of the tail space to increase pull-out torque capability. Based on the three-dimensional finite element method (3D-FEM), the electromagnetic characteristics of an initial model for CPMC are analyzed. In order to facilitate the design and optimization of CPMC, an equivalent three-dimensional (3D) analytical method for the pull-out torque calculation is presented, and its accuracy is verified by comparison with the 3D finite element results. Finally, the influence of design parameters such as half-cone angle, pole pair, pole arc coefficient and permanent magnet thickness on maximum pull-out torque and torque density of CPMC is analyzed, and a preliminary optimization model is obtained.

Numerical simulation of the debonding process in pull-out tests of near-surface mounted FRP rod in concrete

2019 ◽  
Vol 37 (3) ◽  
pp. 1109-1130
Author(s):  
Tie-Lin Chen ◽  
Wenbin Tao ◽  
Wenjun Zhu ◽  
Mozhen Zhou
Keyword(s):  
Three Dimensional ◽  
Crack Model ◽  
Bond Failure ◽  
Near Surface ◽  
Content Type ◽  
Rc Structures ◽  
Pull Out ◽  
Smeared Crack ◽  
Near Surface Mounted ◽  
Debonding Process

Purpose Near-surface mounted (NSM) fiber-reinforced polymer (FRP) rod is extensively applied in reinforced concrete (RC) structures. The mechanical performances of NSM FRP-strengthened RC structures depend on the bond behavior between NSM reinforcement and concrete. This behavior is typically studied by performing pull-out tests; however, the failure behavior, which is crucial to the local debonding process, is not yet sufficiently understood. Design/methodology/approach In this study, a three-dimensional meso-scale finite element method considering the cohesion and adhesion failures is presented to model the debonding failure process in pull-out tests of NSM FRP rod in concrete. The smeared crack model is used to capture the cohesion failures in the adhesive or concrete. The interfacial constitutive model is applied to simulate the adhesion failures on the FRP-adhesive and concrete-adhesive contact interfaces. Findings The present method is first validated by two simple examples and then applied to a practical NSM FRP system. This work studied in detail the debonding process, the bond failure types, the location of peak bond stress, the transmitting deformation in adhesive and the morphology of contact zone. The developed method provides a practical and convenient tool applicable for further investigations on the debonding mechanism for the NSM FRP rod in concrete. Originality/value A three-dimensional meso-scale finite element method considering the cohesion and adhesion failures is presented to model the debonding failure in NSM FRP-strengthened RC structures. The smeared crack model and the interfacial constitutive model are introduced to develop a convenient approach to analyze the failures in adhesive, concrete and related interfaces. The developed numerical method is applicable for studying the debonding process, the bond failure types, the location of peak bond stress, the transmitting deformation in adhesive and the morphology of contact zone in detail.

Matrix cracking and the mechanical behaviour of SiC─CAS composites

1992 ◽  
Vol 437 (1899) ◽  
pp. 109-131 ◽  
Keyword(s):  
Elastic Properties ◽  
Three Dimensional ◽  
Matrix Cracking ◽  
Repeated Loading ◽  
Matrix Composites ◽  
Pull Out ◽  
Matrix Cracks ◽  
Brittle Matrix Composites ◽  
Dimensional Network ◽  
The Matrix

An experimental investigation has been carried out on the mechanical properties of unidirectional (0) 12 , (0, 90) 3S , (±45, 0 2 ) S , and (±45) 3S composites consisting of CAS glass ceramic reinforced with Nicalon SiC fibres. Measurements have been made of the elastic properties and of the tensile, compression and shear strengths of the composites, and these have been supported by a detailed study of the damage which occurs during monotonic and repeated loading. These damage studies have been carried out by means of edge replication microscopy and acoustic emission monitoring. The elastic properties of the composites are, by and large, close to the values that would be predicted from the constituent properties and lay-up sequences, but their strengths are lower than expected, and it appears that the Nicalon reinforcing fibre has been seriously degraded during manufacture. The fracture energy is much higher than predicted from observations of fibre pull-out, and it is suggested that the energy required to form a close three-dimensional network of matrix cracks could account for the high apparent toughness. The matrix cracking stress can be predicted reasonably closely by the Aveston, Cooper and Kelly model of cracking in brittle matrix composites, but it is shown that subcritical microcracks can form and/or grow at stresses well below the predicted critical values without affecting composite properties.

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