چكيده به لاتين
Abstract:
Woven composites in comparison with UD composites have more complicated geometry and more complicated damage mechanisms. Damage mechanisms cause thermodynamically irreversible processes. Entropy characterizes thermodynamic disorders, it can be a measure of damage in systems. According to this issue, experimental measurements published, arguing that materials in low cycle fatigue generate a constant entropy up to the final failure, independent of loading condition, frequency and load level. The generated entropy introduced as a material property in fatigue. This claim was the primary motivation of this research to evaluate constancy of accumulated entropy generation in static loading. Therefore, a new multilevel model which can consider different defects and a mesoscale continuum damage mechanic model has assembled. Elastic properties, initiation and growth of damage in a meaningful physical scale and finally the stress-strain behavior in uniaxial tension and pure shear predicted up to the final strength. Finally, results will confirmed that Accumulated Entropy Generation integrated over loading up to the failure is a material property in static loading apart from fatigue. AEG could be a material property and the measure of the final failure condition. Based on the progression of damage continuum methods and their lack of ability to the determination of the final failure conditions, AEG can be a complement of these models.
Keywords: Composite materials, plain woven, Mesomechanics, Continuum Damage Mechanics, Entropy Generation Method
