Types Of Fiber Reinforced Composites Research Articles

Examining the effect of the shear coefficient on the prediction of progressive failure of fiber-reinforced composites

The ultimate damage of composites under tension usually results from fiber damage, which includes both tensile and shear contributions. In this study, the shear coefficient α of the fiber yarn is incorporated into the failure criterion to consider the shear effect of the fiber yarn. An analytical model is then proposed that combines a homogenization method and the enhanced failure criterion to facilitate quick evaluation of the progressive damage and failure of the composite. The sensitivity of α on the behaviors of progressive damage and failure are comprehensively explored for different types of fiber-reinforced composites, including a laminate, a plain weave composite, a two-dimensional triaxially braided composite, and a three-dimensional woven composite. The results indicate that damage and failure behaviors are generally sensitive to the shear coefficient, and composites with more complex textile structure demonstrates greater sensitivity to the α. An analysis of the sensitivity of α for different failure criteria was also conducted, and the results reveal that the Hashin–Hou criterion shows more sensitivity to α than the Chang–Chang criterion, the Hoffman criterion, or the Tsai–Wu criterion. Therefore, the identification of the shear coefficient is significant for exploring the damage and failure behaviors of fiber-reinforced composites.

Fiber-Reinforced Composites for Full-Arch Implant-Supported Rehabilitations: An In Vitro Study.

Background: Fiber-reinforced composites (FRCs) have been proposed as an alternative to traditional metal alloys for the realization of frameworks in full-arch implant-supported prostheses. The aim of the present in vitro study was to evaluate the deflection under load of seven prostheses endowed with frameworks made of different materials, including different types of fiber-reinforced composites (FRCs). Methods: A master cast with four implant analogues in correspondence with the two lateral incisors and the two first molars was used to create full-arch fixed prostheses with the same shape and different materials. Prostheses were made of the following different materials (framework+veneering material): gold alloy+resin (Au+R), titanium+resin (Ti+R), FRC with multidirectional carbon fibers+resin (ICFRC+AR), FRC with unidirectional carbon fibers+composite (UCFRC+C), FRC with glass fibers+resin (GFRC+AR), FRC with glass fibers+composite (GFRC+C), and resin (R, fully acrylic prosthesis). Flexural tests were conducted using a Zwick/Roell Z 0.5 machine, and the deflection of the lower surface of the prosthesis was measured in order to obtain load/deflection graphs. Results: Greater rigidity and less deflection were recorded for UCFRC+C and GFRC+C, followed by Ti+R and Au+R. The greatest deformations were observed for resin alone, ICFRC+R, and GFRC+R. The results were slightly different in the incisal region, probably due to the greater amount of veneering material in this area. Conclusions: When used to realize full-arch frameworks, Au and Ti allow for predictable mechanical behavior with gradual deformations with increasing load. UCFRC also demonstrated good outcomes and less deflection than ICFRCs when loaded. The GFRC full-arch framework may be a valid alternative, although it showed greater deflections. Further studies are needed in order to evaluate how different prosthesis designs and material thicknesses might affect the outcomes.

Evaluation of interlaminar shear strength of co-cured fiber-reinforced fabric composite structures by lap joint method

Interlaminar shear strength (ILSS) indicates the resistance to interlaminar delamination of fiber-reinforced composite structures. The short beam shear (SBS) method has been commonly used for ILSS measurement, but unwanted failure modes can appear like a compressive or tensile failure in surface, and diagonal shear failure, causing poor measurement accuracy. The lap joint method has advantage that leading to a clear measurement of the shear strength. This paper proposed the lap joint method for extracting ILSS values of co-cured carbon or glass fiber-reinforced fabric composites (CFRC or GFRC) by minimizing the discrepancy between the experiment and finite element analysis of ILSS test. The lap joint method can compensate for the shortcomings of the SBS method. The calculated ILSS based on the lap joint method (LJ-ILSS) with correction factors showed similar values to the ILSS values by SBS method (SBS-ILSS) done by our work and other works of literature. Therefore, the proposed lap joint method has shown potential as a method to measure ILSS of the co-cured fiber-reinforced fabric composites, but also it can be extended to other types of fiber-reinforced composites.

Research on Performance of Vertical FRP Concrete Members

In this paper, the theoretical research on the mechanical properties of FRP concrete vertical stressed members is described. The research progress on the mechanical properties of FRP concrete columns is summarized from three aspects: types of fiber-reinforced composites, applications in civil engineering and development prospects. Finally, the advantages of mechanical properties of FRP concrete column are studied by comparing with concrete filled steel tube column, and the further research direction of FRP concrete column is supplemented.

Evolution of the stiffness tetrad in fiber-reinforced materials under large plastic strain

The main aim of this work is to track the evolution of the stiffness tetrad during large plastic strain. Therefore, the framework of a general finite plasticity theory is developed. Some special cases are examined, and the case of a material plasticity theory is considered more closely. Its main feature is that the elasticity law changes during plastic deformations, for which we develop an approach. As sample materials, we use three types of fiber-reinforced composites. For numerical experiments and verification of the model’s predictions, finite element simulations of representative volume elements for uni-, bi- and tri-directional reinforced materials with periodic boundary conditions are used. From these, we extract the stiffness tetrads before and after large deformations of the material. We quantify the change of the stiffness tetrads due to the fiber reorientation. Finally, we propose an analytical evolution with three parameters that account reasonably well for the evolution of the stiffness tetrad.

Review: creep of fibre-reinforced ceramic matrix composites

ABSTRACTThe content of the review covers, first, generalities on creep. Then, the creep of ceramics and fibres, that are key constituents of fibre-reinforced ceramic matrix composites (CMCs) are addressed. The general features of ceramic matrix composites that may influence the creep behaviour and creep rupture are discussed. Emphasis is placed on microstructure–property relationships and load sharing between fibres and matrix that are critical for CMCs. Then, creep tests and the creep behaviour of various types of fibre-reinforced composites are presented. Mechanisms and models are discussed. The influence of various factors including composite structure, constituent properties (matrix and fibres), interfacial properties and environmental conditions are examined. The paper focuses on non-oxide composites like SiC/SiC that received much attention during the last three decades. Creep of oxide ceramics, fibres and composites are addressed more briefly.

Fracture resistance of premolars teeth restored by silorane, nanohybrid and two types of fiber-reinforced composite: an in-vitro study

Objective The objective was to evaluate and compare the fracture resistance of human maxillary premolars teeth restored with low shrinkage microhybrid composite Silorane-based; Filtek P90 LS, conventional methacrylate-based nanohybrid composite; Ceram X Mono, and two types of fiber-reinforced composites (FRCs); Alert and XENIUS base, micro glass fibers and short glass fibers, respectively in mesio-occluso-distal cavities. Materials and methods A total of 45 human maxillary premolars were selected. Standardized mesio-occluso-distal cavities were prepared in all teeth. Five prepared teeth received no treatment and served as controls (group 1). A total of 40 teeth were randomly divided into four experimental groups (n = 10); group 2: low shrinkage Silorane-based composite, group 3: nanohybrid resin composite, group 4: microfibers reinforced resin composite, and group 5: short fibers reinforced resin composite. Restorations were done for all groups. After being stored 24 h at 37°C, fracture resistance was measured in a universal Instron testing machine by using a 4 mm diameter steel sphere which was applied on tooth buccal and lingual cusps at a cross-head speed of 2 mm/min until fracture occurred. Statistical analysis One-way analysis of variance and Tukey's post-hoc test. Results Highest mean fracture resistance was observed with FRC, nanohybrid, Silorane and lastly with control respectively. Statistically Significant difference was revealed by analysis of variance (P ≤ 0.0001) and Tukey's post-hoc test (P ≤ 0.0001). Conclusion Among the experimental groups, FRC showed the highest fracture resistance.

Mechanical properties and in vivo performance of load-bearing fiber-reinforced composite intramedullary nails with improved torsional strength

Fiber-reinforced composites (FRC) could be feasible materials for fracture fixation devices if the mechanical properties of the composites are congruent with the local structural properties of bone. In a recently developed FRC implant, bisphenol A dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) resin was reinforced with unidirectional E-glass fibers. The addition of a braided glass fiber sleeving to the unidirectional fibers increased the torsional strength (99.5MPa) of the FRC implants at the expense of the flexural strength (602.0MPa). The flexural modulus was 15.3GPa. Two types of FRC intramedullary nails were prepared; first type was FRC as such, second type was FRC with a surface layer of bioactive glass (BG) granules. Experimental oblong subtrochanteric defect was created in 14 rabbits. The defect, which reduced the torsional strength of the bones by 66%, was fixed with an FRC intramedullary nail of either type. The contralateral intact femur served as the control. This model simulated surgical stabilization of bone metastasis. After 12 weeks of follow-up, the femurs were harvested and analyzed by torsional testing, micro-CT and hard tissue histology. Healed undisplaced peri-implant fractures were noticed in half of the animals irrespective of the type of FRC implant. Torsional testing showed no significant differences between the implantation groups. The torsional strength of the bones stabilized by either type of FRC implant was 83% of that of the contralateral femurs. In histological analysis, no implant debris and no adverse tissue reactions were observed. While the mechanical properties of the modified FRCs were suboptimal, the FRC intramedullary nails supported the femurs without structural failure, even in the cases of peri-implant fractures.

Investigation of Moisture Diffusion Process in Fibre Reinforced Composites in Different Environments at Elevated Temperature of Accelerated Hot Wet Resin Matrix

In this study, three types of Fibre Reinforced Composites; Glassfibre/epoxy, Glassfibre/vinylester and Glassfibre/polyester resin were fabricated using Hand lay-up process and compacted in a Hotpress. The specimens of these three types of laminates were studied for Moisture Diffusion in two different environments of Fresh water and Sea water soaking at elevated temperature of 90°C. The kinetics of the Diffusion process for accelerated hot wet resin matrix was studied by computing the Diffusion factors in Fresh water and Sea water and theoretically evaluated. To assess the accelerating effect of higher temperature tests were conducted at elevated temperature of 90°C.

Fracture Strength of Direct Surface-retained Fixed Partial Dentures: Effect of Fiber Reinforcement versus the Use of Particulate Filler Composites Only

This study compared the fracture strengths and analyzed the failure types of direct, surface-retained, anterior fixed-partial-dentures (FPD), reinforced with four types of fiber-reinforced composites (FRC) versus non-fiber-reinforced FPDs made of three particulate filler composites (PFC). To this end, surface-retained anterior FPDs (N = 70, 10 per group) were prepared and divided into seven experimental groups, where Group 1: FRC1 (everStick) + PFC1 (Clearfil Photo Posterior); Group 2: FRC2 (BR 100) + PFC1; Group 3: FRC3 (Interling) + PFC1; Group 4: FRC4 (Ribbond) + PFC1; Group 5: PFC1 only; Group 6: PFC2 only (Sinfony); and Group 7: PFC3 only (Estenia). Fracture strength test was performed after water storage at 37 degrees C for three days (universal testing machine, 1 mm/min). No significant differences were found among the four FRC types veneered with PFC1 (1490 +/- 548--1951 +/- 335 N) (p < 0.05) (ANOVA, Tukey's test). Among all the experimental groups, PFC1 presented a significantly higher mean value (2061 +/- 270 N) than PFC2 (1340 +/- 395 N) (p < 0.05) and all the other FRC-reinforced groups (p < 0.05). Complete pontic fracture was 100% and 70% for PFC2 and PFC3 respectively.

The formulation of constitutive equations for fibre-reinforced composites in plane problems: Part II

From the continuum mechanics points of view, most of commercial fibre-reinforced composites (FRCs) can be considered to be anisotropic materials with one of the five material symmetries: transverse isotropy, orthotropy, tetratropy, hexatropy and octotropy, as illustrated in the preceding paper (Part I) [1]. No properly general formulation of constitutive equations for tetratropic, hexatropic and octoctropic types of FRC has been found in the literature. In this paper, the restriction to the admissible deformation of a FRC imposed by the failure strains of the fibres is investigated. The complete and irreducible two-dimensional tensor function representations regarding tetratropy, hexatropy and octotropy derived in Part I are applied to formulate constitutive equations for FRCs in plane problems of elasticity, yielding and failure in the present work, and of heat conduction, continuum damage and asymmetric elasticity in a continued work (Part III, forthcoming).