Sericin is a structural polypetide of silk, consisting of a unique composition of amino acids. The use of sericin as an ingredient for salad dressing was evaluated in an o/w emulsion system with rape ...oil and vinegar. The low-viscosity sericin from white cocoon showed poor emulsifying activity, whereas non-separable dressing with a low peroxide value (POV) could be produced by the addition of high-viscosity sericin. The use of colored sericin, prepared from yellow-green cocoon shell, maintained a relatively low POV in spite of low viscosity and emulsifying activity levels. Total content of flavonol aglycons in yellow-green sericin was quantified after acid hydrolysis, showing that relatively high amounts of quercetin and kaempferol were detected in the colored sericin.
The purpose of this study was to propose a new numerical modeling of the glass fiber cloth reinforced denture base resin (GFRP). The proposed model is constructed with an isotropic shell, beam and ...orthotropic shell elements representing the outmost resin, interlaminar resin and glass fiber cloth, respectively. The proposed model was applied to the failure progress analysis under three-point bending conditions, the validity of the numerical model was checked through comparisons with experimental results. The failure progress behaviors involving the local failures, such as interlaminar delamination and resin failure, could be simulated using the numerical model for analyzing the failure progress of GFRP. It is concluded that the model was effective for the failure progress analysis of GFRP.
Dynamic viscoelasticity was measured for melts of semi-aromatic liquid crystalline polymer (LCP) filled with:carbon fiber (CF) and glass fiber (GF) to quantitatively analyze their nonlinear ...viscoelastic properties. LCP and its CF and GF filled polymer systems were examined to analyze the dynamic viscoelastic behaviors by Fourier expansion of shear stress wave. For LCP the tertiary terms G'3 and G3 are considerably smaller than their primary terms G'1, and G''1; the viscoelastic property is almost linear. On the other hand, two types of CF filled LCP showed that an increase in the oscillatory angle decreased G'i and Gi in sequence with increasing i. However, the G'3 and G3 values are large enough not to be negligible, i.e. both fiber filled systems show similar nonlinear viscoelastic behaviors. GF filled LCP showed the tendency similar to that for CF filled systems; both G'i and Gi have apparently a plateau region. Furthermore, the values of the ratios G3/G1, G'3/G'1, and G3/G1, are recognized as the indicator of the degrees of their nonlinearity, and the fiber filled LCP systems showed no significant difference in their dependency on ω, although GF filled systems showed a markedly higher nonlinearity of G3/G1, than CF filled systems in a high ω region.
Matrix hybrid laminates can produce the more extensive mechanical properties rather than the conventional laminated composites, because the matrix hybrid laminate has various parameters, resin ratio, ...stacking sequence, fiber orientation and so on. However experimental approach needs long period and high cost in the practical designing. In other words, the application of finite element method to the designing is very effective. In case that the mechanical behaviors of the composite materials are predicted, the modeling method of the heterogeneity for the composite materials is important. In this paper, we proposed the new numerical model that considered the heterogeneity in matrix hybrid laminates. In the proposed model, the heterogeneity is expressed by the combination of two different elements. Using the proposed model, the damage propagation analyses under three-point bending load are carried out. The validity of the proposed model is checked by comparison with experimental results. It is confirmed that the proposed model is effective for the prediction of both the bending properties and damage propagation process. Furthermore, the damage propagation mechanisms of matrix hybrid laminates with different fiber orientation and antisymmetric laminates can be also predicted.
This paper presents a lateral compressive analytical method for CFRP cylinders using the quasi-three-elements which represent fiber and resin respectively. Using this model, the behavior of a
θ/
θ
...sym
(
θ = 15, 30, 45, 60) CFRP cylinder subjected to the lateral compressive load were simulated, and compared with experimental results. The quasi-three-dimensional model is found to be effective for the prediction of the load-displacement curve. For the damage propagation, the transverse crack and interlaminar delamination could be simulated independently. Moreover, the critical strength law using this model was proposed.
A new process to open continuously reinforcing fiber tow was proposed. It consists of a roll part for its preliminary opening and a pneumatic part based on a novel principle for its main opening. ...This process was successfully applied to carbon and glass fiber tows. Three methods for evaluating the degree of tow opening were also proposed and applied to the evaluation of these opened tows. The following results were obtained: In the new combined method, filaments within tow are separated from the state adhered by a sizing agent in the roll part, and the tow is widely opened by the pneumatic part. Thus, much more widely opened tow can be obtained by the combined method, as compared with any of the singular process. The effects of the number of filaments within tow, the breadth/thickness ratio of tow, the compactness caused by sizing, and the diameter of single filament on the opening degree of carbon fiber and glass fiber tows were also clarified.
A new numerical modeling for laminated composites Nishiwaki, Tsuyoshi; Yokoyama, Atsushi; Maekawa, Zen-ichiro ...
Composite structures,
1995, 1995-1-00, 19950101, Letnik:
32, Številka:
1
Journal Article
Recenzirano
Recently, with increasing interest in the performance of fiber reinforced laminated composites, various behaviors of these materials have been simulated by the finite element method (FEM). However, ...conventional models are not good enough to simulate behaviors of laminated composites. The main reason is that the laminated composite is modeled by assuming it to be a homogeneous object though it has a heterogeneous nature. In this paper, the new numerical modeling for laminated composites was proposed. In order to check the validity of the proposed model, elementary simulations were performed and compared with theoretical results. Moreover the application of the proposed model to the laminated composites with interlaminar delamination was discussed.
Localized impact problems for composite structures have recently become important. In this study, some elastic wave velocities in 7-ply GFRP laminate with 0
2/90
3/0
2 ply orientation after low speed ...impact was investigated by using both experimental methods and finite element methods. For the finite element simulation, the quasi-three-dimensional model was used. Comparing the results, the validity for the application of this model to the dynamic problem was estimated. Moreover the quasi-three-dimensional model is applied to the GFRP plates with interlaminar delamination. The relationship between the elastic wave velocities and delaminated states is discussed.
This study deals with the impact property and damage tolerance of matrix hybrid composite laminates with different laminate constitution. The matrix hybrid composite laminates consisted of the ...laminae with a conventional epoxy resin and the laminae with a flexible epoxy resin modified from the conventional resin to avoid the interlaminar delamination. The impact energy absorption ratio greatly depended on the matrix resin placed at the impact face. The energy absorption was almost constant if the conventional resin was placed at the impact surface layer, while it increased exponentially with the increasing fraction of the flexible resin if the flexible resin was placed at the impact face. The impact energy was absorbed by the damage development and propagation in the laminate with conventional resin laminae as the impacted face, while it was absorbed by both the recoverable deformation of the flexible resin and the damage propagation in the laminate with flexible resin laminae as the impacted face.
Tensile properties and the phase morphologies of ABS resins with various rubber particle sizes and graft ratios of SAN are examined. Large rubber particles disperse well in ABS resins irrespective of ...the graft ratio. On the other hand, the graft ratio affects the dispersion state of the small rubber particle, particles with high graft ratio disperse well and those with low graft ratio tend to coalesce into large aggregates. These differences of the morphology strongly alter the deformation mechanism, such as craze formation and cavitation in the rubber particles. The effects of mixing of ABS resins with various graft ratio and particle size on the mechanical properties and phase morphology are also discussed.
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