The High Performance-Discontinuous Fibre (HiPerDiF) method is a new high speed process to produce discontinuous fibre architectures with high volume fraction. It allows the manufacture of tow or tape type prepregs with highly aligned reinforcements directly from short fibres rather than from pre-existing tows. This paper introduces the principle of this unique short fibre alignment method and describes the improved orientation head design for obtaining tape type preforms with high productivity. Using this HiPerDiF method, tensile specimens with 67% of the fibres aligned within the range of ±3° were successfully produced from tape type preforms with 3 mm long carbon fibres. Tensile modulus and strength in the fibre direction of specimens with a fibre volume fraction of 55% were 115 GPa and 1509 MPa, respectively, significantly higher than those of aligned short fibre composites made by conventional methods.

A novel manufacturing method for aligned discontinuous fibre composites (High Performance-Discontinuous Fibre method)

Tensile and compressive behaviors of chopped carbon fiber tapes reinforced thermoplastics have been investigated by varying compression molding conditions (to study the effect of the molding pressure) and the tape length (to analyze the fiber length effect on the mechanical properties of produced composites). Fractographic analysis of prepared specimens conducted after the experiments indicated that the obtained modulus values were almost independent of both the tape length and molding pressure, while the measured strengths exhibited high molding pressure sensitivity. Interlaminar shear strength was considered to be the dominate factor in damage determination during tensile testing, while interlaminar tensile strength played the main role in compression fracture. Increase in the tape length led to a slight increase in the strength magnitude, but also a significant increase in the standard deviation of strength due to the decrease in structural regularity.

Tensile and compressive properties of chopped carbon fiber tapes reinforced thermoplastics with different fiber lengths and molding pressures

In this chapter, a study of design for manufacturing of natural fi bre composites is presented. Initially, the link between design for manufacturing and manufacturing itself is discussed in the context of natural fi bre composites. An account of the manufacturing processes to produce products from natural fi bre composites is given. Various activities of design for manufacturing of natural fi bre composites in various industries are reviewed. Design for sustainability, a recent topic within design for manufacturing or concurrent engineering, in relation to natural fi bre composites is discussed and reviewed. Current work on development of packaging materials from sugar palm fi bre reinforced biopolymer composites encompassing materials selection of biopolymers and some testing is discussed. Finally, a case study on the application of design for sustainability guides for a natural fi bre composite product is presented.

Manufacturing of Natural Fibre Reinforced Polymer Composites

Long fibre-reinforced thermoplastic or long fibre thermoplastic (LFT) composites possess superior specific modulus and strength, excellent impact resistance, and other advantages such as ease of pr...

A review of Long fibre thermoplastic (LFT) composites

A review on MPS method developments and applications in nuclear engineering

This study proposes the layer-wise method (LWM) as a new approach for predicting the tensile strength of discontinuous fiber-reinforced composites that have arbitrary fiber orientation angles. The LWM assumes the discontinuous fiber-reinforced composites are identical to laminates that are composed of unidirectional fiber-reinforced plies and have the same distribution of fiber angles over the entire laminate. We applied the LWM to discontinuous carbon fiber polypropylene composites and evaluated the effect of fiber length on tensile strength and fracture mode. Simulated results agreed well with those of experiments. In addition, we proposed a simple analytical model based on micromechanics. This analytical model can correctly evaluate the strength and the fracture mode as effectively as the LWM. We also compared these models with a rule of mixture considering the failure criterion of fiber breakage and examined the limitation of the rule of mixture in predicting composite strength.

Prediction of tensile strength of discontinuous carbon fiber/polypropylene composite with fiber orientation distribution

The prediction of tensile strength of unidirectional CF/epoxy composites requires appropriately determining the tensile strength distribution of carbon fibers and calculating the stress concentrations around the fiber breaks. In this study, double-fiber fragmentation tests were performed to investigate the stress concentration factor in adjacent fibers around a broken fiber. Simulation results obtained by considering the additional stress concentration due to the matrix cracks correspond well with the fiber breakage behavior observed in experiments. Furthermore, using an additional stress concentration factor and a bimodal Weibull distribution, which has a narrow strength distribution at the short gauge length, the prediction of tensile strength of the unidirectional CF/epoxy composite exhibited a good agreement with experimental results. These results showed that double-fiber fragmentation tests are a valid means of estimating the stress concentrations around fiber breaks.

A study of stress concentrations around fiber breaks in unidirectional CF/epoxy composites using double-fiber fragmentation tests

This paper simulated the microscopic flow in a fiber bundle using the moving particle semi-implicit (MPS) method. Two phases (resin and air) were directly modeled to clarify the detailed mechanism of air entrapments in a fiber bundle. An external force was then introduced into the Navier–Stokes equation using a quasi-potential term to express the wettability between fiber and resin. To validate the MPS method for application to resin flow, we simulated a droplet of resin and the capillary flow of resin between the fibers. To validate the present approach, we simulated water-and-air two-phase flow and compared the simulation results with experiment results. The simulated results for water flow agreed well with the experiment results. Based on these validations, resin-and-air two-phase flow in a fiber bundle was simulated to analyze void formation in a fiber bundle. The simulation indicates that void formation depends on fiber arrangement as well as wettability.

Numerical simulation of microscopic flow in a fiber bundle using the moving particle semi-implicit method

This study investigates the effect of fiber length on the tensile strength for discontinuous fiber composites. A composite with a staggered structure of fiber bundles were prepared by stacking prep...

Hiroaki Matsutani

Papers

Prediction of tensile strength of discontinuous carbon fiber/polypropylene composite with fiber orientation distribution

A study of stress concentrations around fiber breaks in unidirectional CF/epoxy composites using double-fiber fragmentation tests

Numerical simulation of microscopic flow in a fiber bundle using the moving particle semi-implicit method

Effect of fiber length on the tensile strength of unidirectionally arrayed chopped strands

Flow Simulation of Thermoplastic Stampable Sheet Using Particle Method