Circular delaminations : the effect of thermal strains on the strain energy release rate

• Published in: Mechanics of composite materials 2001, Vol.37 (1), p.67-70
• Main Author: CZARNOCKI, Piotr
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Forms of application and semi-finished materials; Laminates; Polymer industry, paints, wood; Technology of polymers
• ISSN: 0191-5665; 1573-8922
• DOI: 10.1023/A:1010695912665

The analysis presented focuses on the extent to which the thermal loading resulting from a difference between the curing and service temperatures and from variations in the thermal-expansion coefficients from layer to layer can affect the growth of delaminations. Square laminate plates containing circular delaminations are examined. The reinforcement combinations for the delaminated layer and the core plate considered are [0 deg ]/[90 deg ], [90 deg ]/[0 deg ], [0 deg ]/[plus/minus45 deg ]s, and [plus/minus 45 deg ] sub s /[0 deg ]. The analysis is carried out using the FEM. The strain energy release rate components are calculated using the modified crack-closure integral method. The results obtained show that, for all the reinforcement combinations studied, with the exception of [plus/minus45 deg ] sub s /[0 deg ], a temperature drop considerably reduces all the strain energy release rate components, but only minor changes in their proportion occur. In the case of the [plus/minus45 deg ] sub s /[0 deg ] plates, all these components increase, and noticeable changes in their proportion are also observed.