On the rule of mixtures for bimetal composites without bonding

A modified rule of mixtures is required to account for the experimentally observed nonlinear variation of tensile strength. A modified Halpin–Tsai model was presented to predict the Young’s modulus of multiscale reinforced composites with both micron-sized and nano-sized reinforcements. In the composites, both micron-sized fillers—carbon fibers—and nano-sized fillers—rubber nanoparticles and carbon nanotubes—are added into the epoxy resin matrix. Carbon fibers can help epoxy resins increase both the tensile strength and Young’s modulus, while rubber nanoparticles and carbon nanotubes can improve the toughness without sacrificing other properties. Mechanical experiments and scanning electron microscopy observations were used to study the effects of the micron-sized and nano-sized reinforcements and their combination on tensile and toughness properties of the composites. The results showed that the combined use of multiscale reinforcements had synergetic effects on both the strength and the toughness of the composites.

Download Full-text

APPLICATION OF THE RULE OF MIXTURES AND HALPIN-TSAI EQUATIONS TO WOVEN FABRIC REINFORCED EPOXY COMPOSITES

JES. Journal of Engineering Sciences ◽

10.21608/jesaun.2006.110251 ◽

2006 ◽

Vol 34 (1) ◽

pp. 227-236 ◽

Cited By ~ 2

Author(s):

M. Abdel Ghafaar ◽

A. A. Mazen ◽

N. A. El-Mahallawy

Keyword(s):

Woven Fabric ◽

Epoxy Composites ◽

Rule Of Mixtures

Download Full-text

Experimental Evaluation of a Steady-State Model for the Wear of Particle-Filled Polymer Composite Materials

Journal of Tribology ◽

10.1115/1.2833871 ◽

1997 ◽

Vol 119 (4) ◽

pp. 694-699 ◽

Cited By ~ 22

Author(s):

Sung Won Han ◽

Thierry A. Blanchet

Keyword(s):

Steady State ◽

Composite Materials ◽

Wear Rate ◽

Polymer Composite ◽

Wear Behavior ◽

Polymer Composite Materials ◽

Volume Fractions ◽

Rule Of Mixtures ◽

Filler Particles ◽

Inverse Rule

A model for the steady-state wear behavior of polymer composite materials, including the effects of preferential load support by and surface accumulation of wear-resistant filler particles, is further developed. It is shown that the resultant inverse rule-of-mixtures description of steady-state composite wear rate behavior is independent of the assumed form of filler contact pressure, though preferential load support does affect the degree of surface accumulation of filler particles that occurs. The validity of these descriptions of steady-state wear behavior and surface accumulation as functions of bulk filler volume fraction are investigated by experiments with copper particle-filled PTFE composites for bulk filler volume fractions from 0 to 40 percent. The applicability of the description of surface accumulation for this composite system was limited to bulk filler volume fractions less than 20 percent, a hypothesized result of transition in load-sharing between filler and matrix. The inverse rule-of-mixtures description of steady-state wear rate, however, was maintained over the full range of volume fractions investigated.

Download Full-text

Bulk high-entropy nitrides and carbonitrides

Scientific Reports ◽

10.1038/s41598-020-78175-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Olivia F. Dippo ◽

Neda Mesgarzadeh ◽

Tyler J. Harrington ◽

Grant D. Schrader ◽

Kenneth S. Vecchio

Keyword(s):

Mechanical Properties ◽

High Temperature ◽

Configurational Entropy ◽

Temperature Stability ◽

High Hardness ◽

Valence Electron Concentration ◽

High Temperature Stability ◽

High Entropy ◽

Rule Of Mixtures ◽

Traditional Ceramics

AbstractHigh-entropy ceramics have potential to improve the mechanical properties and high-temperature stability over traditional ceramics, and high entropy nitrides and carbonitrides (HENs and HECNs) are particularly attractive for high temperature and high hardness applications. The synthesis of 5 bulk HENs and 4 bulk HECNs forming single-phase materials is reported herein among 11 samples prepared. The hardness of HENs and HECNs increased by an average of 22% and 39%, respectively, over the rule-of-mixtures average of their monocarbide and mononitride precursors. Similarly, elastic modulus values increased by an average of 17% in nitrides and 31% in carbonitrides over their rule-of-mixtures values. The enhancement in mechanical properties is tied to an increase in the configurational entropy and a decrease in the valence electron concentration, providing parameters for tuning mechanical properties of high-entropy ceramics.

Download Full-text

Methodology for the analysis of post-tensioned structures using a constitutive serial-parallel rule of mixtures: Large scale non-linear analysis

Composite Structures ◽

10.1016/j.compstruct.2019.02.092 ◽

2019 ◽

Vol 216 ◽

pp. 315-330 ◽

Cited By ~ 2

Author(s):

L.G. Barbu ◽

A. Cornejo ◽

X. Martínez ◽

S. Oller ◽

A.H. Barbat

Keyword(s):

Large Scale ◽

Linear Analysis ◽

Rule Of Mixtures ◽

Non Linear ◽

Post Tensioned

Download Full-text

Test of a rule of mixtures for dry sliding friction of 52100 steel on an Al-Si-Cu alloy

Wear ◽

10.1016/0043-1648(82)90315-5 ◽

1982 ◽

Vol 81 (1) ◽

pp. 187-192 ◽

Cited By ~ 9

Author(s):

Peter J. Blau

Keyword(s):

Sliding Friction ◽

Dry Sliding ◽

Rule Of Mixtures ◽

Cu Alloy ◽

Dry Sliding Friction

Download Full-text

Quantification of Environmental Stress Cracking in Polymer Blends through Eyring Modeling

MRS Proceedings ◽

10.1557/proc-856-bb11.10 ◽

2004 ◽

Vol 856 ◽

Author(s):

Peyton L. Hopson ◽

Robert B. Moore

Keyword(s):

Environmental Stress ◽

Test Sample ◽

Stress Cracking ◽

Rule Of Mixtures ◽

Miscible Blend ◽

Environmental Stress Cracking ◽

Fluid Environment ◽

Immiscible Blend ◽

Craze Initiation

ABSTRACTThe effect of blending polycarbonate (PC) with an amorphous copolyester (PCTG) and a crystallizable polyester (PBT) on the environmental stress cracking (ESC) resistance was studied. The determination of the ESC resistance for the blend was accomplished through tensile testing in a fluid environment utilizing an Eyring-type activated process to describe ESC. It was found that the miscible blend, PC/PCTG, displayed a rule of mixtures for ESC resistance to all fluids tested except ether resistance. The immiscible blend, PC/PBT, displayed a significant negative deviation from the rule of mixtures for ESC resistance, except for ether resistance, which has been attributed to the development of stress sites for craze initiation at the interface between the blend components on the surface of the test sample. The differences in ether resistance compared to the trends found for the fluid ESC resistance in this study were attributed to possible changes in crystallization for the samples tested in ether. The data suggests that strongly swelling fluids, e.g. diethyl ether in the presence of PC, may cause densification from polymer crystallization resulting in voids that facilitate in the initiation and growth of crazes.

Download Full-text