Performance loss of Terfenol-D particle epoxy composites under cyclic magneto-mechanical loading at the matrix glass transition start and finish temperatures

2004 ◽  
Vol 369 (1-2) ◽  
pp. 267-274
Author(s):  
Manikantan Shanmugham ◽  
Harold Bailey ◽  
William D Armstrong
Keyword(s):  
Glass Transition ◽  
Mechanical Loading ◽  
Epoxy Composites ◽  
Matrix Glass ◽  
Performance Loss ◽  
The Matrix

Comparison of Magnetostrictive Performance Loss of Particulate Tb0.3 Dy0.7 Fe2 Epoxy Composites Prepared with Different Matrix Polymers M. Shanmugham et al.: Comparison of Magnetostrictive Performance Loss of Particulate Tb0.3 Dy0.7 Fe2 Epoxy Composites

2004 ◽  
Vol 19 (3) ◽  
pp. 795-805 ◽  
Author(s):  
Manikantan Shanmugham ◽  
Harold Bailey ◽  
William D. Armstrong
Keyword(s):  
Magnetic Field ◽  
Glass Transition ◽  
Matrix Material ◽  
Epoxy Composites ◽  
Particulate Composites ◽  
Specimen Preparation ◽  
Performance Loss ◽  
Magnetostrictive Strain ◽  
Relative Damage ◽  
Low Modulus

Particulate composites of magnetostrictive Terfenol-D were prepared with polyamine and anhydride cured epoxy polymer matrices with the presence or the absence of a strong magnetic field. These composites were studied to investigate (i) the influence of magnetic field that is applied during specimen preparation in strain output levels, (ii) performance loss at high temperatures, and (iii) the influence of matrix material in magnetostrictive strain performance. A six-way comparison is made of materials processed under magnetic field with materials processed under no magnetic field, and magnetostrictive strain performance at glass transition finish temperature with magnetostrictive strain performance at glass transition start temperature, and magnetostrictive strain performance in low modulus matrix systems with magnetostrictive strain performance in high modulus matrix systems. A four-way comparison is also made between the micrographs for strain-cycled and non-strain-cycled samples and relative damage incurred by samples prepared using high and low modulus matrix systems.

Ballistic impact response of carbon/epoxy tubes with variable nanosilica content

2017 ◽  
Vol 52 (12) ◽  
pp. 1589-1604 ◽  
Author(s):  
Aniruddh Vashisth ◽  
Charles E Bakis ◽  
Charles R Ruggeri ◽  
Todd C Henry ◽  
Gary D Roberts
Keyword(s):  
Fracture Toughness ◽  
Shear Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Impact Damage ◽  
Mass Density ◽  
Impact Response ◽  
Residual Shear Strength ◽  
Damage Area ◽  
The Matrix

Laminated fiber reinforced polymer composites are known for high specific strength and stiffness in the plane of lamination, yet relatively low out-of-plane impact damage tolerance due to matrix dominated interlaminar mechanical properties. A number of factors including the toughness of the matrix can influence the response of composites to impact. The objective of the current investigation is to evaluate the ballistic impact response of carbon/epoxy tubes with variable amounts of nanosilica particles added to the matrix as a toughening agent. Mass density, elastic modulus, glass transition temperature and Mode I fracture toughness of the matrix materials were measured. Tubes manufactured with these matrix materials were ballistically impacted using a round steel projectile aimed at normal incidence across the major diameter. After impact, the tubes were nondestructively inspected and subjected to mechanical tests to determine the residual shear strength in torsion. Increasing concentrations of nanosilica monotonically increased the modulus and fracture toughness of the matrix materials. Tubes with nanosilica had smaller impact damage area, higher residual shear strength, and higher energy absorbed per unit damage area versus control materials with no nanosilica. Overall, the addition of nanosilica improved the impact damage resistance and tolerance of carbon/epoxy tubes loaded in torsion, with minimal adverse effects on mass density and glass transition temperature.

scholarly journals Epoxy Resin Composite Bilayers with Triple-Shape Memory Effect

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xixi Li ◽  
Yaofeng Zhu ◽  
Yubing Dong ◽  
Meng Liu ◽  
Qingqing Ni ◽  
...  
Keyword(s):  
Glass Transition ◽  
Electron Microscope ◽  
Shape Memory ◽  
Memory Effects ◽  
Epoxy Composites ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Shape Memory Effects ◽  
Triple Shape Memory ◽  
Nanosilica Particles

Triple-shape memory epoxy composites with bilayer structures of well-separated glass transition temperatures have been successfully prepared. The different glass transition temperatures of the epoxy composites were obtained by physically incorporating various amounts of nanosilica particles, which were introduced into the epoxy by utilizing polyethylene glycol. A scanning electron microscope and a transmission electron microscope were used to analyze the dispersibility of the nanosilica particles. The effects of nanosilica particles on the mechanical properties as well as on the dual-shape memory effects (DSME) and triple-shape memory effects (TSME) of the nanocomposites were studied. The nanosilica particles were homogenously dispersed in the matrix and well incorporated into the epoxy matrix. The resulting nanocomposites exhibited excellent TSME, and their shape fixity properties were significantly improved by nanosilica particles.

scholarly journals Characterization of continuous Hibiscus sabdariffa fibre reinforced epoxy composites

2022 ◽  
Vol 30 ◽  
pp. 096739112110609
Author(s):  
Atik Mubarak Kazi ◽  
Ramasastry DVA
Keyword(s):  
Fibre Orientation ◽  
Stress Transfer ◽  
Dynamic Mechanical Properties ◽  
Epoxy Composites ◽  
Neat Epoxy ◽  
Hibiscus Sabdariffa ◽  
Sem Images ◽  
Fibre Composites ◽  
The Matrix

The influence of fibre orientation on physical, mechanical and dynamic mechanical properties of Hibiscus sabdariffa fibre composites has been studied. The composites with longitudinal (0°), transverse (90°) and inclined (45°) fibre orientation were prepared using the hand layup technique. ASTM standards were used for characterization of continuous Hibiscus sabdariffa fibre composites. The composite with longitudinally placed fibres yields improved mechanical characteristics. The addition of longitudinal (0°) oriented continuous Hibiscus sabdariffa fibres to the epoxy enhances tensile strength by 460%, flexural strength by 160% and impact strength by 603% compared to neat epoxy. The longitudinal (0°) fibre oriented composite offers higher resistance to water absorption and thickness swelling compared to other types of composites. All continuous Hibiscus sabdariffa fibre epoxy composites possess an improved storage modulus than the neat epoxy resin. The glass transition temperature of continuous Hibiscus sabdariffa fibre composites is 8%–31% lower than that of neat epoxy. Scanning electron microscopy (SEM) images confirm the existence of voids in the matrix, fibre pullout and crack propagation near the fibre bundle, which indicates the stress transfer between fibre and matrix is non-uniform.

scholarly journals Synthesis and Characterization of Natural Fibers Reinforced Fiber Epoxy Composites

2015 ◽  
Vol 51 ◽  
pp. 47-53
Author(s):  
U. Mahaboob Basha ◽  
D. Mohana Krishnudu ◽  
P. Hussain ◽  
K. Manohar Reddy ◽  
N. Karthikeyan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Natural Fibers ◽  
Epoxy Composites ◽  
Synthesis And Characterization ◽  
Mechanical And Thermal Properties ◽  
Epoxy System ◽  
Pennisetum Typhoides ◽  
The Matrix ◽  
Reinforced Fiber

In the current work epoxy resin is chosen as matrix, treated Sacharum offinarum ( SugarCane) fiber, Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler are chosen as reinforcement. Room temperature cured Epoxy System filled with Sacharum offinarum fiber and Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler are synthesised by mechanical shear mixer, then kept in a Ultra sonic Sonicator for better dispersion of Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler in the matrix. Different weights of modified Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler (1,2,3,4,5 gm wt) has been incorporated into the Epoxy matrix in order to study the variation of Mechanical and Thermal properties.

scholarly journals Fatigue Behaviour of Unidirectional Single-Walled Carbon Nanotube Reinforced Epoxy Composite under Tensile Load

2003 ◽  
Vol 12 (1) ◽  
pp. 096369350301200 ◽  
Author(s):  
Y. Ren ◽  
F. Li ◽  
H. M. Cheng ◽  
K. Liao
Keyword(s):  
Carbon Nanotube ◽  
Tensile Load ◽  
Fatigue Behaviour ◽  
Epoxy Composites ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Matrix Cracks ◽  
The Matrix

Tension-tension fatigue behaviour of unidirectional, aligned single-walled carbon nanotube (SWNT) rope reinforced epoxy composites were studied. While the slope of the stress-life (S-N) curve of the SWNTs in SWNT/epoxy composites obtained is flat, similar to those of carbon fibre reinforced epoxy composites, the fatigue strength of the former is at least twice that of the latter. Morphology of the fatigue fracture surface of SWNT reinforced epoxy involves matrix plastic deformation and SWNT-bridged matrix cracks. Evidence of good adhesion between SWNTs and epoxy was seen, and pullout length of SWNTs from the matrix is about 30 μm. Results suggest that carbon nanotubes can be used for fatigue resistant, high fracture toughness composites.

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