scholarly journals Numerical Research on the Pullout Failure of GFRP Bolt

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yanqing Wang ◽  
Beicheng Wu ◽  
Yu Guo ◽  
Haifeng Yang
Keyword(s):  
Shear Stress ◽  
Elastic Modulus ◽  
Interface Layer ◽  
Fiber Pullout ◽  
Interface Shear ◽  
Interface Shear Stress ◽  
Glass Fiber Reinforced ◽  
The Matrix ◽  
Pullout Failure ◽  
The Ideal

The fiber pullout is a main failure after the fiber is broken in the tension of glass fiber reinforced polymer (GFRP) bolt. In this paper, the numerical analysis is done on the distribution of both fiber normal force and interface shear stress. The results show that, on the ideal interface, the fiber pullout occurs from the lower end to the upper end of the matrix gradually, and both the normal stress of the fiber and the shear stress of the ideal interface gradually increase from the lower end to the upper end. With the increase of the interface layer thickness, the shear stress concentration area on the interface is enlarged while the stress applied is reduced, and the displacement of GFRP deformation is increasing sharply. This means that the capacity of GFRP deformation is enhanced. As a soft elastic body, the interface layer with a smaller elastic modulus can make the fiber stress and the interface shear stress sharply small and well dispersed. In addition, the load can be effectively transferred to the reinforced phase fibers in a bigger interfacial layer elastic modulus with a certain strength.

Modeling matrix fracture in fiber-reinforced ceramic-matrix composites with different fiber preforms

2019 ◽  
Vol 90 (7-8) ◽  
pp. 909-924 ◽  
Author(s):  
Longbiao Li
Keyword(s):  
Elastic Modulus ◽  
Ceramic Matrix Composites ◽  
Interface Debonding ◽  
Matrix Composites ◽  
Multiple Fracture ◽  
Fiber Volume ◽  
Interface Shear ◽  
Interface Shear Stress ◽  
The Matrix ◽  
Fiber Preforms

In this paper, the stress-dependent matrix multiple fracture in silicon carbide fiber-reinforced ceramic-matrix composites with different fiber preforms is investigated. The critical matrix strain energy criterion is used to determine the matrix multiple fracture considering the interface debonding. The effects of the fiber radius, fiber elastic modulus, matrix elastic modulus, fiber volume, interface shear stress, and interface debonded energy on the matrix multiple fracture and the interface debonding are analyzed. The experimental matrix multiple cracking and interface debonding of minicomposite, unidirectional, and two-dimensional woven SiC/SiC composites with different fiber volumes and interphases are predicted. The matrix cracking density increases with the increasing of the fiber volume, fiber elastic modulus, interface shear stress, and interface debonded energy, and the decreasing of the fiber radius and matrix elastic modulus.

Interface Shear Stress of Concrete Beams Strengthened with FRP in Salt Water

2012 ◽  
Vol 446-449 ◽  
pp. 3499-3502
Author(s):  
Chen Zhao ◽  
Pei Yan Huang ◽  
Zhong Song Chen
Keyword(s):  
Shear Stress ◽  
Concrete Beam ◽  
Salt Water ◽  
Interfacial Shear Stress ◽  
Interfacial Properties ◽  
Interfacial Shear ◽  
Interface Shear ◽  
Interface Shear Stress ◽  
Bond Slip ◽  
Relationship Model

Based on existing methods and results of other research, the bond-slip relationship model is given and the distrubition of shear stress of concrete beam strengthened by FRP in salt water is derived. Through a specific example to analyze the distribution of interfacial shear stress, and the different effects caused by different aggressive environment on the interfacial properties. The results show that: 1) Interfacial shear stress will sharply reduce with increasing distance from the end; 2) Different environments have different effects on the interface properties of FRP strengthened beams. Salt water erosion influnce the interfacial properties of FRP strengthened beams significantly.

The Flexural Strength of Glass Fiber Reinforced Polyester Filled with Aluminum Tri-Hydroxide and Montmorillonite

2018 ◽  
Vol 772 ◽  
pp. 28-32 ◽  
Author(s):  
Sunarto Kaleg ◽  
Dody Ariawan ◽  
Kuncoro Diharjo
Keyword(s):  
Elastic Modulus ◽  
Flexural Strength ◽  
Glass Fiber ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Gfrp Composite ◽  
The Matrix

Aluminum tri-hydroxide (ATH) and montmorillonite (MMT) are capable to enhance flame retardancy of glass fiber reinforced polymer (GFRP). Nevertheless, the combination of both flame retardant fillers on changes in the mechanical properties of GFRP is not yet known. The characterization of flexural strength and scanning electron microscope (SEM) observation on GFRP composite has been done. The result of flexural properties testing shows that the addition of ATH or MMT or a combination of both on the GFRP causes a decrease in flexural strength. GFRP with increased ATH loading causes an increase in elastic modulus. Contrarily, the MMT addition causes a decrease in the elastic modulus of the GFRP composite. SEM results on the fractured samples show that the high content of ATH or MMT in the UP tends to agglomerate thus showing visible holes that were formed from the filler particles pulled out from the matrix.

scholarly journals A Coupled 1D Film Hydrodynamics and Core Gas Flow Model for Air-Oil Flows in Aero-Engine Bearing Chambers

2017 ◽  
Author(s):  
B. Kakimpa ◽  
H. P. Morvan ◽  
S. Hibberd
Keyword(s):  
Shear Stress ◽  
Operating Conditions ◽  
Engine Oil ◽  
Interface Shear ◽  
Interface Shear Stress ◽  
Oil Film ◽  
Film Model ◽  
Aero Engine ◽  
Film Interface ◽  
Engine Bearing

A robust 1D film hydrodynamic model has been sequentially coupled with a 1D core gas model and used to predict the instantaneous mean core gas speed, film interface shear stress and liquid film distribution within an idealised bearing chamber. This novel approach to aero-engine bearing chamber simulation provides a predictive tool that can be used for the fast and reliable exploration of a set of bearing chamber design and operating conditions characterised by the: chamber dimensions, air/oil fluid properties, shaft speed, sealing air flows, oil feed rates and sump scavenge ratios. A preliminary validation of the model against available bearing chamber flow measurements from literature shows good agreement. The model represents a significant step change in predictive capabilities for aero-engine oil system flows compared to previous semi-empirical models. The bearing chamber is idealised as a one-dimensional (2D) domain with a predominantly azimuthal flow in both the rotational oil film and core gas such that axial components may be ignored. A 1D system of depth-averaged film hydrodynamics equations is used to predict oil film thickness and mean speed distributions in the azimuthal direction under the influence of interface shear, gravity, pressure gradient and surface tension forces. The driving shear stress in the film model is obtained from the 1D core-gas model based on an azimuthal gas momentum conservation equation which is coupled to the film model through the interface shear stress and film interface velocity.

Interface Shear Stress Analysis of Concrete Beam Strengthened with CFRP

2011 ◽  
Vol 71-78 ◽  
pp. 1348-1353 ◽  
Author(s):  
Yong Chao Zhou ◽  
Tie Jun Sun
Keyword(s):  
Shear Stress ◽  
Stress Analysis ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Bending Moment ◽  
Failure Model ◽  
Interface Shear ◽  
Concentrated Load ◽  
Interface Shear Stress ◽  
Basic Assumptions

Based on elastic theory, the four basic assumptions and the failure model of concrete beams strengthened with CFRP, deduced the formulae about the concrete beams strengthened with CFRP with concentrated load. Results show the biggest interface shear stress is at the at the anchor end, it not only relate to the material property of CFRP and concrete, but also to the thickness, width and bending moment at the anchor end etc.. Reducing CFRP stiffness and thickness or increasing viscose layer thickness, these can reduce the maximum interface shear stress at the end of anchoring.

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