Third party funded individual grant
Acronym: ZH 1372/1-1
Start date : 01.02.2025
End date : 31.01.2027
Glassy polymers can transition from ductile to brittle under certain conditions such as aging or decreased temperatures, leading to sudden breakage with minimal energy absorption and potential accidents. Enhancing the toughness of glassy polymers without compromising stiffness is a significant scientific challenge, yet the mechanisms behind the brittle-to-ductile transition (BDT) remain not fully understood. In crystalline materials, the BDT is often attributed to the kinetics of dislocations, but this explanation cannot be directly applied to glassy materials due to the absence of well-defined microscopic structures of such plastic carriers like dislocations. Molecular dynamics (MD) simulations have shown that spatial fluctuations of local mechanical properties at the atomistic scale and geometric loading conditions are crucial in the BDT of glassy materials. However, addressing the effects of geometric loading conditions under non-uniform deformations is challenging in pure MD simulations due to computational constraints on system sizes. To overcome this limitation, this project employs a multiscale simulation method by embedding an MD domain into a continuum domain to conduct nonuniform deformation boundaries for the MD system. This approach enables a better understanding of the interactions between plastic carriers and the relationship between local structures and global mechanical properties in glassy polymers.