Abstract

In this study, deformation mechanisim in microcellular polymers is empirically investigated. Linear elastic and plastic deformation processes of foam injection molded specimens are examined under tension loading. The full-field surface displacement is determined by using 3D digital image correlation (DIC) method. By the help of this vision system, strain distribution around the crack and during crack propagation can be defined. For this purpose, the ARAMIS 4M in-situ visualization system is operated with the ARAMIS Professional software which is used for calibration, image acquisition and evaluation of the test results (Figure 1(a)). The accuracy of measured displacement and strain is found to be depended on speckle size [1]. Therefore, the pattern sprayed on the specimen surface is compared with the reference image provided by GOM (Braunschweig, Germany) (Figure 1(b)). Additionally, the quantitative study of structure and properties relationship is carried out to eleborate the deformation tendency of the predefined morphological properties. In this respect, reflected light microscopy (RLM) and scanning electron microscopy (SEM) are used for 2D and X-ray micro-computer tomography (μCT) is used for 3D structure characterization. The significant morphological qualities such as cell diameter, cell density and sphericity of cells are determined via a multiple linear regression model to predict the mechanical properties.

References

[1] Lecompte, D., Sol, H., Vantomme, J., & Habraken, A. (2006). Analysis of speckle patterns for deformation measurements by digital image correlation, Conference Paper in Proceedings of SPIE, doi:10.1117/12.695276.