Java application for springback analysis of composite plates

• Analytical model of springback phenomenon was developed.
• Model was programmed in Matlab and then transformed to Java with GUI.
• Comparison of the predicted results with measured data shows good agreement.
• Developed software was distributed to the manufacturer of the composite parts.

The use of hi-tech thermoplastic matrices (e.g. PEKK, PEEK or PPS) in carbon fiber-reinforced composites is growing, mainly in the aircraft industry. The manufacturing process is carried out at higher temperatures, which leads to residual stresses and dimensional changes of the manufactured part. Our work is focused on making an analytical prediction of the springback angle of C/PPS laminate with textile reinforcement. Better prediction will make the manufacturing tool more precise. Our analytical model took into account the temperature change, the moisture change and resin shrinkage during the cure cycle (which is crucial for semi-crystalline matrices). The analytical model is based on classical lamination theory (CLT) and an equation for through thickness characteristics. The description of the model was written in Matlab code, which was subsequently transformed into Java with GUI for easier input of the characteristics of the composite (lay-up, materials, angle of the layer, radii, volumetric fiber fraction and characteristics of the textile reinforcement-number of threads in warp and weft direction, thickness, type of weave, etc.) The results from our program were compared with the results measured by the manufacturer, and good agreement was achieved.