Study of Thermal Stress of Iron-Boron Alloy Casing

2011 ◽  
Vol 311-313 ◽  
pp. 1039-1043
Author(s):  
Yun Zhang ◽  
Yong Di Li ◽  
Jian Jun Wu
Keyword(s):  
Thermal Stress ◽  
Stress Distribution ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Internal Surface ◽  
Stressed Condition ◽  
Fiber Volume ◽  
The Matrix ◽  
Thermal Stress Distribution ◽  
Properties Of Composites

The outer casing of heater made of iron-boron alloy is brittle fractured easily. It is a an effective way to add continuous fibers in brittleness material to improve the mechanical properties of composites. Temperature and thermal stress distribution of iron-boron alloy casing and the influence of thickness on the thermal stress of the casing is computed with finite element method, and the thermal stress distribution and influence of fiber volume fraction of continuous fiber-reinforced composites is studied. The result indicates that the external surface is in tensile stressed condition, and the internal surface is in compression stressed condition; the thermal stress increases with the thickness. The compression stress of the matrix decreases and the tensile stress increases with the increasing of the fiber volume fraction.

Determination of fiber volume fraction in a cured laminate

2021 ◽  
pp. 002199832110112
Author(s):  
Qing Yang Steve Wu ◽  
Nan Zhang ◽  
Weng Heng Liew ◽  
Vincent Lim ◽  
Xiping Ni ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fiber Volume Fraction ◽  
Evaluation Method ◽  
Volume Fraction ◽  
Matrix Material ◽  
Volume Ratio ◽  
Gravimetric Analysis ◽  
Fiber Volume ◽  
Laser Ultrasonic ◽  
The Matrix

Propagation of ultrasonic wave in Carbon Fiber Reinforced Polymer (CFRP) is greatly influenced by the material’s matrix, resins and fiber volume ratio. Laser ultrasonic broadband spectral technique has been demonstrated for porosity and fiber volume ratio extraction on unidirection aligned CFRP laminates. Porosity in the matrix materials can be calculated by longitudinal wave attenuation and accurate fiber volume ratio can be derived by combined velocity through the high strength carbon fiber and the matrix material with further consideration of porosity effects. The results have been benchmarked by pulse-echo ultrasonic tests, gas pycnometer and thermal gravimetric analysis (TGA). The potentials and advantages of the laser ultrasonic technique as a non-destructive evaluation method for CFRP carbon fiber volume fraction evaluation were demonstrated.

Development of Generalized Plane-Strain Tensors for the Concentric Cylinder

1995 ◽  
Vol 62 (3) ◽  
pp. 590-594
Author(s):  
N. Chandra ◽  
Zhiyum Xie
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Transformation Strain ◽  
Inclusion Problem ◽  
Infinite Domain ◽  
Concentric Cylinder ◽  
Finite Radius ◽  
Fiber Volume ◽  
Thermal Residual Stresses ◽  
The Matrix

A pair of two new tensors called GPS tensors S and D is proposed for the concentric cylindrical inclusion problem. GPS tensor S relates the strain in the inclusion constrained by the matrix of finite radius to the uniform transformation strain (eigenstrain), whereas tensor D relates the strain in the matrix to the same eigenstrain. When the cylindrical matrix is of infinite radius, tensor S reduces to the appropriate Eshelby’s tensor. Explicit expressions to evaluate thermal residual stresses σr, σθ and σz in the matrix and the fiber using tensor D and tensor S, respectively, are developed. Since the geometry of the present problem is of finite radius, the effect of fiber volume fraction on the stress distribution can be easily studied. Results for the thermal residual stress distributions are compared with Eshelby’s infinite domain solution and finite element results for a specified fiber volume fraction.

The Influence of Alloy Chemistry on Controlling Fiber Volume Fraction in Ni-Base Mc Aligned Eutectics

1981 ◽  
Vol 12 ◽  
Author(s):  
M. R. Jackson ◽  
J. L. Walter
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Major Influence ◽  
Ideal Solution ◽  
Fiber Volume ◽  
Strong Function ◽  
Alloy Chemistry ◽  
Ideal Solution Behavior ◽  
Small Influence ◽  
The Matrix

ABSTRACTFor the Ni-base TaC eutectics, it has been shown previously that carbide volume fraction is a strong function of Ta/C ratio. Now in a number of Ni,Cr-TaC and Ni,Cr,Al-TaC alloys, Cr has been observed to have only a small influence on volume fraction of carbide, while Al has a major influence acting to decrease the volume fraction. The Al present in the matrix causes the phase equilibrium to approach that of a much greater Ta/C ratio. This analysis has been extended to more complex NiTaC alloys as well. For the simple Ni-Cr-Ta-C alloys, creep behavior has been studied as a function of volume fraction of carbide.Other carbide systems have been evaluated as well, including TiC and NbC. A general understanding of volume fraction differences between these systems and TaC can be reached by consideration of ideal solution behavior and the appropriate phase diagrams.

Effect of Fiber Volume Fraction on High Temperature Creep of Al2O3-SiO2(sf)/AZ91D Composite

2011 ◽  
Vol 474-476 ◽  
pp. 548-552
Author(s):  
Jun Tian
Keyword(s):  
Creep Resistance ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Matrix Alloy ◽  
Short Fiber ◽  
Tensile Creep ◽  
Short Fibers ◽  
Creep Tests ◽  
Fiber Volume ◽  
The Matrix

Constant stress tensile creep tests were conducted on AZ91D–20 vol.%, 25 vol.%, and 30 vol.% Al2O3-SiO2short fiber composites and on an unreinforced AZ91D matrix alloy. The creep resistance of the reinforced materials is shown to be considerably improved compared with the matrix alloy. With the increasing volume fraction of short fibers, the creep resistance of AZ91D composites is improved, and their creep threshold stresses are also increased accordingly. Because of the increasing volume fraction of short fibers, loads of bearing and transmission of short fibers will increase, and thus the creep resistance of AZ91D composites further improves, but the precipitation of β-Mg17Al12precipitate increases in the number, it is easy to soften coarse, so that threshold stress of AZ91D composite does not increase greatly.

Experimental Investigation of Interface Properties in SiC Fiberreinforced Reaction-Bonded Silicon Nitride Matrix Composites

1994 ◽  
Vol 365 ◽  
Author(s):  
J.I. Eldridge ◽  
R.T. Bhatt
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Ceramic Matrix Composites ◽  
Interfacial Properties ◽  
Interface Properties ◽  
Matrix Composites ◽  
Fiber Volume ◽  
The Matrix ◽  
Push Out ◽  
Spacing Method

ABSTRACTInterfacial properties of 1-D SiC/RBSN composites were measured by the matrix crack spacing method and by the fiber push-out method, and the results were compared. The composites consisted of 8 to 33 vol% of aligned SCS-6 SiC fibers (142 μm diameter) in a relatively porous (20 to 40 vol%) Si3N4 matrix. The effects of fiber volume fraction and test temperature on the interfacial properties have been investigated. The advantages and limitations of both methods in evaluating the interface properties of fiber-reinforced ceramic matrix composites and the factors influencing the interfacial measurements are discussed.

Evaluating the effect of variable fiber content on mechanical properties of additively manufactured continuous carbon fiber composites

2020 ◽  
pp. 073168442096321
Author(s):  
Dakota R Hetrick ◽  
Seyed Hamid Reza Sanei ◽  
Charles E Bakis ◽  
Omar Ashour
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Content ◽  
Fiber Volume ◽  
Transverse Strength ◽  
Continuous Carbon Fiber ◽  
3D Printed ◽  
Properties Of Composites

Fiber volume fraction is a driving factor in mechanical properties of composites. Micromechanical models are typically used to predict the effective properties of composites with different fiber volume fractions. Since the microstructure of 3D-printed composites is intrinsically different than conventional composites, such predictions need to be evaluated for 3D-printed composites. This investigation evaluates the ability of the Voigt, Reuss, and Halpin–Tsai models to capture the dependence of modulus and strength of 3D-printed composites on varying fiber volume fraction. Tensile coupons were printed with continuous carbon fiber-reinforced Onyx matrix using a Markforged Mark Two printer. Specimens were printed at five different volume fractions with unidirectional fibers oriented at either [Formula: see text] to obtain longitudinal, shear, and transverse properties, respectively. It is shown that the Voigt model provides an excellent fit for the longitudinal tensile strength and a reasonable fit for the longitudinal modulus with varied fiber content. For the transverse direction, while the Reuss model fails to capture the transverse modulus trend, the Halpin–Tsai model provides a reasonable fit as it incorporates more experimental parameters. Like conventional composites, addition of fibers degrades the transverse strength, and the transverse strength decreases with increasing fiber volume fraction. The shear modulus variation with fiber content could not be fitted reasonably with either Halpin–Tsai model or Reuss model.

Design Method for Braiding Process and Structure Parameters of Three Dimensional Two-Step Tubular Braided Preform

2010 ◽  
Vol 150-151 ◽  
pp. 1613-1616
Author(s):  
Yan Gao ◽  
Jia Lu Li
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Design Method ◽  
General Structure ◽  
Three Dimensional ◽  
Structure Parameters ◽  
Fiber Volume ◽  
General Methodology ◽  
Properties Of Composites

The properties of composites reinforced by three dimensional braided preform are determined by braiding structure significantly. The main objective of this paper is to develop a general methodology for the determination of the design and analysis of three dimensional two-step braided tubular preform. The arrangement pattern of axial yarns with various finenesses is derived for the uniform braiding structure of preform, which offers a possibility for achieving preferable interior structures of braided tubular preforms. Then, the general structure parameters, including the interrelation between surface braiding angles and interior braiding angles and the fiber volume fraction, are investigated in some detail. The results derived from this paper can provide a useful method for the design of 3D two-step tubular braided preform.

Mechanical Properties of Interface Layers in SiC/TiAl Composite

2021 ◽  
Vol 1016 ◽  
pp. 151-155
Author(s):  
Keizo Hashimoto ◽  
Jiang Jin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Stress ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Volume ◽  
Sic Fiber ◽  
Pull Out ◽  
Interface Layers ◽  
Properties Of Composites

Although metal matrix composites (MMC) for the high temperature structural material have been investigated extensively for many years, applications of MMC have been still limited. Among many combinations between the ceramic fibers and the matrix materials, combination of SiC fiber and TiAl based intermetallic compounds has been expected to be one of the best combination, since both SiC fiber and TiAl have demonstrated the capabilities of the low density heat resistant materials. SiC fiber reinforced TiAl composites have been successfully fabricated using hot press method. Optimum temperature and pressure have been determined. SiC/TiAl composite having relatively low fiber volume fraction shows nearly an ideal elastic property applying the law of mixture. Effects of interface layers on the mechanical properties of composites have been studied in detail. Micro-indentation on a single fiber was carried out to examine the pull out strength of SiC fiber quantitatively. Estimated shear stress on the interface was 145-195MPa, those values are quite reasonable since the tensile strength of TiAl matrix was 420MPa and the maximum shear stress would be the half of tensile strength according to Schmid law. Three-point bending tests have been carried out to evaluate the mechanical properties of composites. Fiber volume fraction 8.9% specimen shows ideal bending stiffness compare with the calculated values based on the low of mixture. Reaction layers and the interface between SiC fiber and TiAl have been analyzed by SEM-EDS and XRD. At least two or more reaction layers have been identified. These reaction layers can be explained based on the Si-Ti-C ternary equilibrium phase diagram at 1373K. Optimum conditions of interface structure will be discussed

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