Characterization and modeling of the laser-based separation process and resulting damage mechanisms of carbon fiber reinforced plastics under fatigue loading

点击翻译按钮获取中文摘要

The aim of the research project is the simulation development for the determination of temperature fields in laser processing, characterization of their effects on the damage development, and the damage mechanisms of carbon fiber reinforced plastics (CFRP) under cyclic loading. For this purpose, unidirectional (UD) CFRP with various matrix materials, thermoset epoxy resin (EP) and thermoplastic polyamide 6.6 (PA) will be produced and cut by means of laser processing. The material to be separated evaporates in the laser beam focus, generating thermally induced damage referred to as heat affected zones (HAZ). To determine the mechanical characteristics, with superimposed mechanical-thermal stress, fatigue tests are carried out. Integrated fiber Bragg grating (FBG) sensor, as well as thermocouples, provide the basis for temperature and strain measurement during laser processing and mechanical testing. In order to obtain conclusions about CFK damage mechanisms, in a further step intermittent in-situ computed tomography (CT) investigations are performed and correlated with the previous results. In combination with the experimental investigations, a simulation will be developed which describes the machining process in terms of intensity, speed and material removal depending on the material used and the laminate structure and predicts the resulting temperature fields during the processing of the finished component. On the basis of these data, the characteristics of the HAZ should be determined. By parallel verification of the results by means of experiments, the simulation is iteratively optimized.