Micromechanical analysis of fatigue and crack growth in carbon-fiber epoxy composites based on mechanical testing

摘要

The paper presents static and dynamic tests of carbon/epoxy composite materials with fiberorientation at 0°/90° and ±45°. The main tensile properties were determined as a basis forsubsequent dynamic tests, in which permanent dynamic strength, crack growth, and crackgrowth rate in the material due to the action of fatigue load were assessed. Comparisonswere made regarding the structure of the tested specimens. Samples were obtained fromprepregs with a specific density of 1600 kg/m3. The tests were performed at roomtemperature. Scanning electron microscopy (SEM) was used to analyze the damage in thematerial during these tests, the mechanisms of their further damage progression and, theimpact on the growth and growth rate of the initial crack in the material. The analysis ofnumerical results and micromechanical analysis confirmed the dominant role of thereinforcing structural element in the material in all performed tests. The obtained results areof great importance in the application of composite materials of such structures underdifferent operating conditions and load regimes.