Effects Of Interphase Properties Research Articles

Magnetic, mechanical, electrical properties and coupling effects of particle reinforced piezoelectric polymer matrix composites

The 0-3 polymer-based magnetoelectric (ME) composites have the advantages of easy preparation, low cost, good flexibility, environmental friendliness and biological affinity, etc., and have a wide range of applications prospect in the biomedical field, such as the biological microelectronics, nanomedicine technology treatment, bone tissue healing and so on. The ME performance of this composite is jointly contributed by the properties of its component and microstructure. In this work, considering the impact of interphase effect, and the relationship between the effective properties of 0-3 ME composites and its microstructure is established, and the expressions of the Young's modulus, permeability, dielectric coefficient, piezoelectric coefficient, piezomagnetic coefficient and ME coefficient are obtained respectively. The effects of interphase properties and particle sizes on the effective properties of ME composites are discussed. By comparison, our theoretical results are in good agreement with experimental data. Then the influence of some factors on its effective performance is discussed. The results show that the effective properties of 0-3 ME composites are strongly dependent on the volume fraction ratio and size of the particles, the applied magnetic field. There is an optimal volume ratio and magnetic field to maximize ∂ α E 33 /∂ H 3 .

Effect of Interphase Properties on Isothermal and Non-isothermal Crystallization Behavior of Poly(lactic acid)/Acetylated Starch Blends.

The effect of interphase properties on the crystallization behavior of blends of poly(lactic acid) (PLA)/acetylated starch (AS) with different degrees of substitution (DSs) was investigated. Under isothermal crystallization conditions, the rate of crystallization was higher for PLA/DS0.5 and lower for PLA/DS1.5 and PLA/DS2.5 when compared to PLA. In contrast, non-isothermal crystallization behavior indicated a slower rate of crystallization of PLA/DS0.5 and a faster rate of crystallization of PLA/DS1.5 and PLA/DS2.5 compared to PLA at the highest cooling rate (5 °C/min). The potential relationship between crystallization behavior and interphase properties and interphase thickness and formation of rigid amorphous fraction in the interphase, was investigated. The formation of a rigid amorphous fraction in PLA/DS1.5 and a thick interphase in PLA/DS2.5 prevented the formation of crystals on the dispersed phase and interrupted the crystallization under isothermal conditions. Hydrogen bonding in the PLA/DS1.5 blend and hydrophobic interactions in the PLA/DS2.5 blend may facilitate the crystallization at high cooling rates under non-isothermal conditions. Small-angle X-ray scattering analysis revealed the presence of a smaller lamellar structure in PLA/AS blends. The largest amorphous phase among blends was observed for the PLA/DS1.5 blend, which can be attributed to the hydrogen bonding in the interphase region of this blend.

Nonlinear dynamic analysis of FG carbon nanotube/epoxy nanocomposite cylinder with large strains assuming particle/matrix interphase using MLPG method

In this paper, a first known study on the large deformation dynamic behavior of functionally graded carbon nanotube-reinforced (CNTR) nanocomposite cylinder considering the particle/matrix interphase property is presented. The geometrically nonlinear dynamic analysis is carried out using the meshless local Petrov–Galerkin (MLPG) method based on the total Lagrangian approach. The obtained nonlinear time dependent equations are solved using the incremental-iterative Newmark/Newton–Raphson technique. The effective properties of CNTR cylinder is evaluated by employing the three-phase Halpin–Tsai model and rule of mixture. In these models, three constituent phases including nanoparticle, interphase and matrix is considered. It is assumed that CNTs is dispersed in the resin matrix with four different function along the radial direction to obtain the optimum grading pattern. The effects of interphase properties, CNT's weight fraction, CNT distribution pattern and volume fraction exponent on the dynamic characteristics of the cylinder are discussed in details. Numerical results demonstrated the high performance of the proposed MLPG method for geometrically nonlinear dynamic analysis of functionally graded carbon nanotube/epoxy nanocomposites due to its advantage in eliminating the mesh distortion and high capability in FG material modeling. Moreover, it is found that the interphase properties may dramatically affect the dynamic behavior of nanocomposite cylinder especially at the higher CNT volume fractions. So, it is important to consider the interphase properties to correctly model the nanocomposite structures.

A generalized self-consistent model for interfacial debonding behavior of fiber reinforced rubber matrix sealing composites

This paper presents an experimental and numerical study of short-fiber-reinforced rubber matrix sealing composites (SFRC). The transverse tensile stress-strain curves of SFRC are obtained by experiments. Based on the generalized self-consistent method, a representative volume element (RVE) model is established, and the cohesive zone model is employed to investigate the interfacial failure behavior. The effect of interphase properties on the interfacial debonding behavior of SFRC is numerically investigated. The results indicate that an interphase thickness of 0.3 μm and an interphase elastic modulus of about 502MPa are optimal to restrain the initiation of the interfacial debonding. The interfacial debonding of SFRC mainly occurs between the matrix/interphase interface, which agrees well with results by scanning electron microscope (SEM).

Development of Nicolais–Narkis model for yield strength of polymer nanocomposites reinforced with spherical nanoparticles

In this paper, the Nicolais–Narkis model for yield strength of polymer nanocomposites containing spherical nanoparticles is developed assuming the role of interphase between polymer and nanofiller phases. The predictions of the developed model are compared with the experimental results and also, the effects of interphase properties on the yield strength are expressed.The calculated results show that the developed model can give much accurate predictions for yield strength of nanocomposites by proper thickness and strength of interphase, while the yield strength is under-predicted by disregarding of interphase. The developed model demonstrates that the yield strength improves by reduction in nanoparticle size and increment in interphase thickness. Also, the detrimental effect of weak interfacial adhesion between polymer matrix and nanoparticles is revealed.

Effect of interphase properties on fracture behavior of TCP/PLA composites

In the present study, the effects of interphase on the mechanical properties of β-tricalcium phosphate (β-TCP) particle-dispersed bioabsorbable poly(lactic acid) (PLA) composites were investigated. In order to improve interfacial strength between PLA and β-TCP, the surface of β-TCP was modified with L-lactic acid (LLA) monomer. The weight ratios of LLA to β-TCP are selected as 1.5, 3, 4.5, 6, 7.5%. Tensile strength decreased with the incorporation of β-TCP to PLA, whereas the tensile strength of composites was improved in the case of modification with the weight ratio of 3%. From acoustic emission measurements, initial interfacial debonding was also suppressed up to 3%. From finite elemental analysis, elastic modulus of interphase is about 30–70% of that of PLA and elastic modulus of the composites do not depend on interphase thickness. From the stress distributions at initial debonding onset, it is clarified that interfacial debonding is caused by shear stress between particle and interphase and interfacial shear strength seems to be about 20 MPa.

Influence of Interphase Properties on the Macroscopic Response of Single- and Double-Walled CNT/Epoxy Nanocomposites: A Numerical Study

A concept for improving the impact resistance of carbon fibre reinforced plastic (CFRP) laminates by using a carbon nanotube (CNT)/epoxy surface coating is presented. An initial parametric numerical study shows the effects of interphase properties on the macroscopic stress-strain behaviour of carbon nanotube/epoxy nanocomposites. Finite element (FE) simulations carried out for fully aligned single-walled CNTs (SWCNTs) and double-walled CNTs (DWCNTs) investigated the influence of properties of the polymer/CNT interphase and the interwall phase of DWCNTs. They reveal that a high shear stiffness of the CNT/polymer interphase is essential to take the full advantage of the load-bearing ability of the inner wall of the DWCNT, and thus enhance the mechanical performance of the nanocomposite. Furthermore the interphase shear stress distributions in interwall and CNT/polymer interphase of a DWCNT point out the relationship between CNT/epoxy interphase damage propagation and shear stress in the interwall phase.

Effect of interphase properties on the damping response of polymer nano-composites

In this paper a finite element (FE) based unitcell model has been devised with periodic boundary conditions to calculate the effective tan δ of a composite as a function of frequency. Using this method, it is demonstrated that the tan δ of the nano-composite manifests important information about the extent and properties of the interphase region that surrounds each nano-particle. Thus we imply that tan δ measurements provide a simple yet useful experimental tool to understand more about the interphase. However, severe agglomeration or wide size distribution of the nano-particles may introduce errors in measurement.

複合材料 単繊維埋蔵横方向引張試験における初期損傷に及ぼす界面相特性の影響

The embedded single fiber transverse tensile test has been proposed as a new experimental evaluation method on composite interfaces. The effect of surface treatment on microscopic damage, such as the interfacial debonding and matrix cracking around a fiber was investigated by in-situ SEM observation, when the transverse tensile load to the fiber longitudinal direction was applied to an embedded single fiber composite. The experimental result revealed that the surface treatment condition of fibers has an influence on the initiation and propagation of interfacial debonding and matrix cracking around a single fiber. In addition, the effect of interfacial properties on microscopic damage was investigated by a finite element analysis. The analysis was carried out by using a three layers model, which was modeled separately, fiber, matrix and interphase into the test specimen. The property for the interphase was assumed to be orthotropic, i.e. both tensile and shear moduli of the interphase are dealt independently to express the role of interphase for stress bearing and stress transfer separately. The effect of interphase properties was investigated by changing the tensile and shear moduli of the interphase. The reasonable elastic properties of the interphase were obtained by comparing the computational results with experimental ones. The Hoffman's failure criterion was used for judging of the damage in the interphase and the matrix. The validity of this analytical method is verified by comparing the analytical results with the experimental ones.

Analysis of interphase mechanical behavior with interface element in the composite materials

In this paper, stress distribution is obtained by employing the interface element to simulate the interphase feature between fiber-matrix in single-ply laminar which consists of fiber arranged periodically in the x-axis direction and matrix, and which is subjected to far-field transverse load the contour of stress σxx and radial stress στ in the vicinity of interphase are plotted for three different interphase cases. It is made known that the effect of interphase properties on stress distribution is obvious.

On the Role of Interphases in the Transverse Failure of Fiber Composites

A numerical investigation into the effect of interphase properties on the transverse strength of unidirectional fiber-reinforced composites is carried out in the con text of plane strain linear elasticity. The phase geometry of the composite is modeled by a regular hexagonal array of fibers in a matrix, and the interphase behavior is represented by a constrained spring layer model. A variationally coupled finite element-boundary ele ment method is used to obtain the mechanical response of a cell containing a center fiber and parts of surrounding fibers. We assume matrix cracking to be the predominant mode of failure. It is demonstrated that the interphase properties significantly affect the overall cracking patterns. Issues regarding the strength and integrity of the composite are dis cussed.

The Effects of Interphase Properties on Interfacial Shear Strength in Polymer Matrix Composites

Abstract The effects of interphase elastic modulus, glass transition temperature, and thickness on interfacial shear strength were investigated both experimentally and theoretically. Single fiber fragmentation tests were performed over a range of temperatures on samples with tailored interphases. Three different types of interphases were investigated: high modulus/high glass transition temperature, low modulus/low glass transition temperature and uncoated (no tailored interphase). A reduction in interfacial shear strength with temperature was observed for all three types of samples tested. The magnitude of this decrease was found to correlate with the glass transition temperature of the interphase. The low Tg interphase samples showed large reductions in IFSS, while samples with a higher Tg coating showed only a small decrease. A three-phase, axisymmetric elasticity solution was developed to predict the sensitivity of the stress state to the interphase material properties and temperatures used in the experimental studies. Predictions which incorporated the change in modulus of both the matrix and interphase with temperature were in good agreement with the experimental trends. Both the theoretical and experimental results supported the existence of an interphase with reduced glass transition in the uncoated samples.