Effects of random laminate misalignment on macroscopic and microscopic elastic/viscoplastic behaviors of ultrafine plate–fin structures

In this study, the effects of random laminate misalignment on the macroscopic and microscopic elastic/viscoplastic behaviors of ultrafine plate–fin structures are statistically investigated adopting Monte Carlo simulation. To this end, a multiscale method that analyzes the elastic–viscoplastic behavior of ultrafine plate–fin structures with random laminate misalignment both macroscopically and microscopically is proposed based on the homogenization theory for nonlinear time-dependent materials combined with the substructure method. Using the method, Monte Carlo simulations for elastic and elastic–viscoplastic behaviors of ultrafine plate–fin structures subjected to uniaxial tension or simple shear are performed for many cases of random laminate misalignment. The obtained results reveal that the random laminate misalignment affects the microscopic behavior of ultrafine plate–fin structures more than the macroscopic behavior; microscopic stress and viscoplastic strain exhibit considerable variability depending on the laminate misalignment, and their maximum values can become about 30–50% higher than those in the case without laminate misalignment. This suggests the importance of considering random laminate misalignment in the design and strength/life prediction of ultrafine plate–fin structures.