The buckling of multiwalled carbon nanotubes under torsional load coupling with temperature change is researched. The effects of torsional load, temperature change, surrounding elastic medium, and van der Waals forces between the inner and outer nanotubes are taken into account at the same time. Using continuum mechanics, an elastic multishell model with thermal effect is presented for buckling of a multiwalled carbon nanotube embedded in an elastic matrix under thermal environment and torsional load. Based on the model, numerical results for the general case are obtained for the thermal effect on buckling of a multiwalled carbon nanotube under torsional load. It is shown that the buckling torque of a multiwalled carbon nanotube under a certain value of temperature change is dependent on the wave number of torsional buckling modes, and a conclusion is drawn that at room or lower temperature the critical torsional load for infinitesimal buckling of a multiwalled carbon nanotube increases as the value of temperature change increases, while at temperature higher than room temperature the critical torsional load for infinitesimal buckling of a multiwalled carbon nanotube decreases as the value of temperature change increases.

Molecular dynamics (MD) simulation was carried out to study the moisture diffusion in cross-linked epoxy resin, with the influence of temperature, water concentration and polymer conversion taken into account. The simulation results showed that the moisture diffusion coefficients increased with the increase in temperature. And generally, with the increased moisture concentration or decreased polymer conversion, the moisture diffusion coefficients reduced. However, the moisture diffusion was strongly inhibited when the number of epoxy groups in completely reacted epoxy resins was equal to the number of water molecules.

Honeycomb structures have attracted wide attention due to outstanding mechanical properties as promising light material structures. Inspired by nature and artistic design, various honeycombs with different microstructural configurations have been designed for the sake of better mechanical performances and functions. Here, the Miura-origami reentrant honeycomb (MRH) structure integrating reentrant honeycombs (RH) and Miura-origami structures is investigated systematically. Dynamic impact behaviors of the present MRH structure are investigated numerically. The deformation modes and energy absorption capacity of RH and MRH are compared under different impact velocities, including low-velocity, medium-velocity and high-velocity. The results show that the plateau stress and the specific energy absorption(SEA) of MRH is much higher than RH. Moreover, the parametric study indicates that raising the inclined angle will decrease the plateau stress and the absolute value of Poisson’ratio for MRH structures. The specific energy absorption curves increase as the inclined angle of MRH grows up. In addition, the MRH with smaller dihedral angle can absorb much more impact energy and the variation of absorbed energy is proportional to the cell wall thickness of the MRH structure. This work is expected to provide a new thought for designing advanced energy absorption metastructures and achieving superior mechanical performances.