Investigation of failure mechanisms in polymer composites by simultaneous measurement of ultra-small-angle scattering and acoustic emission during the deformation. I. Method

Abstract

Failure mechanisms in polymer composites were investigated with the method of ultra-small-angle X-ray scattering using synchrotron radiation and acoustic emission analysis simultaneously. The composites were prepared from polystyrene filled with glass beads with different coatings. The two-dimensional scattering patterns were analyzed by means of a cylinder model, while the curves of the acoustic emission signals per stress or amplitude interval were calculated and fitted by a Weibull distribution function.

Simulating and evaluating small-angle X-ray scattering of micro-voids in polypropylene during mechanical deformation

“…43, 603-610 Stefan Fischer et al Micro-voids in polypropylene 605 Figure 1The model for scattering by micro-voids proposed by Karl et al (1999). Such voids can be modelled as randomly distributed cylinders which are oriented along the stretching direction, showing a log-normal size distribution.…”

“…The model for scattering by micro-voids proposed by Karl et al (1999). Cylinders, representing the voids and aligned along the stretching direction, are randomly distributed in the sample.…”

Failure Mechanism of Brass with Three V‐Notches Characterized by Acoustic Emission in In Situ Three‐Point Bending Tests

“…The AE has been generally used in engineering applications for internal defects, [21,22] crack initiation, [23,24] fatigue life, [25,26] fracture location, [27,28] evaluation of the failure mechanisms, and process and damage characterization. [29,30] In this paper, three V-notches specimens with different relative depth ratio a/h and relative distance ratio a/(a þ c) are characterized by the AE under in situ three-point bending (TPB) tests. [31,32] This paper aims at investigating the amplitude and energy of AE signals by the TPB test on the three V-notches specimens, and whether such AE signals are dependent on the V-notches' relative depth ratio a/h and relative distance ratio a/(a þ c) severity.…”

An <i>In Situ</i> Three-Point Bending Study on Pre-Notch 7075 Aluminium Alloy with Acoustic Emission

“…In the recent decades, in order to study the deformation materials mechanics behavior, three different forms of specimens are used, no notch, pre-crack and notch specimen. 24) No notch specimen and pre-crack are two extreme conditions of notch specimen. In other words, the opening angles of notch specimen ranges from 0 degree to 180 degrees.…”

“…Since the AE was firstly found by Kaiser in 1950s, the AE has been widely applied in engineering applications for internal defects and crack initiation, 16,17) fatigue life, 18,19) fracture location, 20,21) damage characterization 22,23) and evaluation the failure mechanisms and process. 24,25) In this paper, AE signals are employed to characterize three typical cases, the no notch, pre-crack and V notch specimens of 7075Al under TPB. The present paper aims to investigate the intensity of AE signals by the TPB on the notch specimens, and the relationship between the AE signals and the notch severity.…”