Shear band stability and uniform elongation of gradient structured material: Role of lateral constraint

Here we report a shear bands-dominated deformation principle for the gradient material composed of two nanostructured gradient layers (NGLs) and a coarse-grained (CG) interior. Multiple shear bands form in the NGL to accommodate the applied strain. The magnitude of uniform elongation depends on shear band stability, and shear band stability is determined by the intensity of constraint between NGL and CG interior. Specifically, the stronger the constraint, the denser and more stable the shear bands dispersed in the NGL, thereby leading to larger uniform elongation. This finding sheds insight into the theoretical basis of harnessing dispersed stable shear bands in heterostructures by optimizing microstructure architecture.