Transverse Fractures

Fig, 6.17. Fracture process zone (FPZ) in transverse fracture of unidirectional fiber composite. After... 

Crack growth resistance (R-curve) behavior in transverse fracture... 

IMPROVEMENT OF TRANSVERSE FRACTURE TOUGHNESS WITH INTERFACE CONTROL... 

Chapter 7. Improvement of transverse fracture toughness with interface control... 

Further details of the above techniques to improve the transverse fracture toughness of composites by controlled interfaces of various nature and modifying materials are discussed in the following sections. The effectiveness of these toughening methods on transverse fracture toughness and strength in relation to the controls are summarized in Table 7.1. 

Fibers Transverse fracture Flexural strength Interlaminar shear Interlaminar... 

It is shown in Section 7.2 that the PVAL coating applied onto Kevlar and carbon fibers is potentially beneficial for improving the transverse fracture toughness of the composites made therefrom. Encouraged by this promising result, further studies were conducted on the effects of the compliant interlayer on the stress distributions. 

As with cotton and other cellulosics, the use of the electron microscope has aided the evaluation of mechanical degradation and wear of wool fabrics. Scale removal and fibrillation were more representative of normal wear, whereas a variety of fiber faults were observed on wool fabrics abraded by laboratory testers such faults included longitudinal splitting, transverse fracture, and abraded fibrils (172). 

Characters.—Flat pieces, uncoated or deprived of the periderm, rarely in coated quills, from six to eighteen inches long, one to three inches wide, and two to four tenths of an inch thick, compact and heavy outer surface brown, marked by broad, shallow, irregular, longitudinal depressions inner surface tawny-yellow and flbrous transverse fracture shortly and finely fibrous. Powder cinnamon-brown, somewhat aromatic persistently bitter. 

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