Bayesian estimation of single ply anisotropic elastic constants from spherical indentations on multi-laminate polymer-matrix fiber-reinforced composite samples

Meccanica ◽  
2020 ◽  
Author(s):  
Andrew R. Castillo ◽  
Surya R. Kalidindi
Keyword(s):  
Bayesian Estimation ◽  
Polymer Matrix ◽  
Elastic Constants ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Anisotropic Elastic ◽  
Composite Samples

Shear Lag Model for Regularly Staggered Short Fuzzy Fiber Reinforced Composite

2014 ◽  
Vol 81 (9) ◽  
Author(s):  
S. I. Kundalwal ◽  
M. C. Ray ◽  
S. A. Meguid
Keyword(s):  
Polymer Matrix ◽  
Interfacial Shear Stress ◽  
Stress Transfer ◽  
Fiber Reinforced ◽  
Shear Lag ◽  
Fiber Reinforced Composite ◽  
Shear Lag Model ◽  
Transfer Characteristics ◽  
Reinforced Composite ◽  
Lag Model

In this article, we investigate the stress transfer characteristics of a novel hybrid hierarchical nanocomposite in which the regularly staggered short fuzzy fibers are interlaced in the polymer matrix. The advanced fiber augmented with carbon nanotubes (CNTs) on its circumferential surface is known as “fuzzy fiber.” A three-phase shear lag model is developed to analyze the stress transfer characteristics of the short fuzzy fiber reinforced composite (SFFRC) incorporating the staggering effect of the adjacent representative volume elements (RVEs). The effect of the variation of the axial and lateral spacing between the adjacent staggered RVEs in the polymer matrix on the load transfer characteristics of the SFFRC is investigated. The present shear lag model also accounts for the application of the radial loads on the RVE and the radial as well as the axial deformations of the different orthotropic constituent phases of the SFFRC. Our study reveals that the existence of the non-negligible shear tractions along the length of the RVE of the SFFRC plays a significant role in the stress transfer characteristics and cannot be neglected. Reductions in the maximum values of the axial stress in the carbon fiber and the interfacial shear stress along its length become more pronounced in the presence of the externally applied radial loads on the RVE. The results from the newly developed analytical shear lag model are validated with the finite element (FE) shear lag simulations and found to be in good agreement.

scholarly journals Adherence of Streptococcus mutans to Fiber-Reinforced Filling Composite and Conventional Restorative Materials

2009 ◽  
Vol 3 (1) ◽  
pp. 227-232 ◽  
Author(s):  
Lippo V.J Lassila ◽  
Sufyan Garoushi ◽  
Johanna Tanner ◽  
Pekka K Vallittu ◽  
Eva Söderling
Keyword(s):  
Surface Roughness ◽  
Streptococcus Mutans ◽  
Polymer Matrix ◽  
Bacterial Adhesion ◽  
Glass Fibers ◽  
Composite Resins ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Restorative Materials

Objectives. The aim was to investigate the adhesion of Streptococcus mutans (S. mutans) to a short glass fibers reinforced semi-IPN polymer matrix composite resin. The effect of surface roughness on adhesion was also studied. For comparison, different commercial restorative materials were also evaluated. Materials and Methods. Experimental composite FC resin was prepared by mixing 22.5 wt% of short E-glass fibers, 22.5 wt% of IPN-resin and 55 wt% of silane treated silica fillers using high speed mixing machine. Three direct composite resins (Z250, Grandio and Nulite), resin-modified glass ionomers (Fuji II LC), amalgam (ANA 2000), fiber-reinforced composite (FRC) (everStick and Ribbond), and pre-fabricated ceramic filling insert (Cerana class 1) were tested in this study. Enamel and dentin were used as controls. The specimens (n=3/group) with or without saliva were incubated in a suspension of S. mutans allowing initial adhesion to occur. For the enumeration of cells on the disc surfaces as colony forming units (CFU) the vials with the microbe samples were thoroughly Vortex-treated and after serial dilutions grown anaerobically for 2 days at +37°C on Mitis salivarius agars (Difco) containing bacitracin. Bacterial adhesion was also evaluated by using scanning electron microscopy. Surface roughness (Ra) of the materials was also determined using a surface profilometer. All results were statistically analyzed with one-way analysis of variance (ANOVA). Results. Composite FC resin and other commercial restorative materials showed similar adhesion of S. mutans, while adhesion to dentin and enamel was significantly higher (p<0.05). Surface roughness had no effect on bacterial adhesion. Saliva coating significantly decreased the adhesion for all materials (p<0.05). Composite FC resin had a significantly higher Ra value than control groups (p<0.05). Conclusions. Short fiber-reinforced composite with semi-IPN polymer matrix revealed similar S. mutans adhesion than commercial restorative materials.

scholarly journals The Effect of Surface Roughness on Repair Bond Strength of Light-Curing Composite Resin to Polymer Composite Substrate

2013 ◽  
Vol 7 (1) ◽  
pp. 126-131 ◽  
Author(s):  
Timo T. Kallio ◽  
Arzu Tezvergil-Mutluay ◽  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu
Keyword(s):  
Surface Roughness ◽  
Bond Strength ◽  
Polymer Matrix ◽  
Shear Bond Strength ◽  
Weibull Modulus ◽  
Composite Resin ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Particulate Filler

Objective: The purpose of this study was to analyze the shear bond strength of a new composite resin to polymer-based composite substrates using various surface roughnesses and two kinds of polymer matrices. Materials and methods: Particulate filler composite resin with cross-linked polymer matrix and fiber-reinforced composite with semi-interpenetrating polymer matrix were used as bonding substrates after being ground to different roughnesses. Substrates were aged in water for one week before bonding to new resin composites. Twelve specimens in the substrate groups were ground with grinding papers of four grits; 320, 800, 1200 and 2400. Results: Corresponding values of surface roughness (Ra) varied from 0.09 to 0.40 for the particulate filler composite resin and 0.07 to 0.96 for the fiber-reinforced composite resin. Characteristic shear bond strength between the new resin and particulate filler composite resin was highest (27.8 MPa) with the roughest surface (Weibull modulus: 2.085). Fiber-reinforced composite showed the highest bond strength (20.8 MPa) with the smoothest surface (Weibull modulus: 4.713). Conclusions: We concluded that surface roughness did not increase the bonding of new resin to the substrate of IPN based fiber-reinforced composite, whereas the roughness contributed to bonding the new resin to the particulate filler composite resin with a cross-linked polymer matrix.

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