Multiscale model of deformation and strength characteristics of dispersed carbon nanotube-reinforced polymers

• Applicants: Professor Dr.-Ing. Sergiy Antonyuk; Professor Oleksandr Hondliakh, Ph.D.
• Subject Area: Mechanical Process Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 554884501

In the design of polymer composite materials for functional purposes, there is currently a focus on enhancing their strength, reliability and durability. One effective approach is the development of novel nanomodified materials based on carbon nanotubes (CNT). The phenomenon of the "nano-reinforcement paradox" can be observed in materials reinforced with CNT particles. At relatively low concentrations, the material exhibits enhanced strength. However, with an increase in CNT concentration, the strength significantly decreases. The relationship between the concentration and deformation processes at the nanoscale level of individual CNT particles and the macroscopic mechanical behavior of the reinforced polymer components remains poorly understood. In this context, the objective of this project is to develop a multiscale approach, which is based on physically-based models that describe the processes of formation and accumulation of defects at the nanoscale, the evolution of their propagation at the microscale and the subsequent determination of the nonlinear physical and mechanical characteristics of nanomodified polymers at the macroscale. The development of this multiscale approach will be carried out by experimental studies of the formulation process and the resulting properties of the nanomodified polymers, as well as the numerical modeling of defect formation with the finite element method on nano- and micro-scales. For the description of the formulation process, a deterministic method will be applied that allows a detailed study of all the evolutionary processes occurring during dispersion, taking into account the deagglomeration of CNT, the formation of gas bubbles and the change of the temperature during ultrasonic treatment, as well as the change of the gas bubbles during the degassing process up to the stationary state of the nanomodified epoxy. In order to characterize the dispersion method the online measurements of the deagglomeration kinetics of CNT agglomerates in polymer suspensions will be performed by the extinction method, which will be adapted to on-line measurement during the ultrasonic dispersion process. The influence of the dispersion process on the microstructure, strength parameters and nonlinear physical and mechanical characteristics of components will be experimentally investigated. Based on the combination of the obtained experimental and numerical results a multiscale model will be developed which accurately describes the mechanics of nanomodified polymers. Moreover, new multiscale strength criteria for nanomodified polymers will be developed to assess the strength and reliability of produced components.

• DFG Programme: Research Grants