Location

La Jolla, CA

Start Date

1-1-1998 12:00 AM

Description

The mechanical performance of fibre reinforced polymer and metal matrix composites is, among other factors, closely related to the fibre/matrix interfacial shear strength and to the tensile strength distribution of the fibre during loading. Single fibre composite (SFC) tests are well known as an experimental procedure used for assessing interfacial as well as fibre strength [1, 2]. A fibre is embedded along the centre line of a dog-bone shaped specimen of matrix material. When this specimen is strained in a uniaxial tensile test, the single fibre fragments repeatedly. If the strain to failure of the matrix material is sufficiently high, the fragmentation process comes to an apparent standstill (saturation) before the fracture of the entire dog-bone specimen. Conclusions are drawn with respect to the desired strength parameters of the fibre and the fibre/matrix interface from the fragmentation process and from the resulting fibre fragment length. Although the SFC test appears quite simple, various inherent mechanical and statistical difficulties exist and there is still a lack in understanding the failure processes of composites. For better interpretation of these processes it is important to know the stress distribution around the fibre while loading. Finite Element Modeling and other simulation methods are one way to get a better understanding on a micromechanical scale [3]. Looking at experimental techniques in association with the SFC-test among other techniques (like acoustic emission [4]), microscopic and photoelastic investigations are used to investigate fibre fracture and to localize fibre break [2, 5]. Works with photoelastic analyses to study micro mechanical interactions between broken fibres and nearby unbroken fibres (and birefringing matrix materials) were performed with conventional polariscopes [5].

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

17B

Chapter

Chapter 5: Engineered Materials

Section

Composites

Pages

1201-1208

DOI

10.1007/978-1-4615-5339-7_155

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

In-Situ Observation of the Stress Field of the Failure Process in Single Fibre Reinforced Polymers

La Jolla, CA

The mechanical performance of fibre reinforced polymer and metal matrix composites is, among other factors, closely related to the fibre/matrix interfacial shear strength and to the tensile strength distribution of the fibre during loading. Single fibre composite (SFC) tests are well known as an experimental procedure used for assessing interfacial as well as fibre strength [1, 2]. A fibre is embedded along the centre line of a dog-bone shaped specimen of matrix material. When this specimen is strained in a uniaxial tensile test, the single fibre fragments repeatedly. If the strain to failure of the matrix material is sufficiently high, the fragmentation process comes to an apparent standstill (saturation) before the fracture of the entire dog-bone specimen. Conclusions are drawn with respect to the desired strength parameters of the fibre and the fibre/matrix interface from the fragmentation process and from the resulting fibre fragment length. Although the SFC test appears quite simple, various inherent mechanical and statistical difficulties exist and there is still a lack in understanding the failure processes of composites. For better interpretation of these processes it is important to know the stress distribution around the fibre while loading. Finite Element Modeling and other simulation methods are one way to get a better understanding on a micromechanical scale [3]. Looking at experimental techniques in association with the SFC-test among other techniques (like acoustic emission [4]), microscopic and photoelastic investigations are used to investigate fibre fracture and to localize fibre break [2, 5]. Works with photoelastic analyses to study micro mechanical interactions between broken fibres and nearby unbroken fibres (and birefringing matrix materials) were performed with conventional polariscopes [5].