Numerical studies of shear banding in interface shear tests using a new strain calculation method

• Published in: International journal for numerical and analytical methods in geomechanics Vol. 31; no. 12; pp. 1349 - 1366
• Main Authors: Wang, Jianfeng, Gutierrez, Marte S., Dove, Joseph E.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.10.2007; Wiley
• Subjects: Applied sciences; Buildings. Public works; Computation methods. Tables. Charts; discrete element methods; Exact sciences and technology; Geotechnics; interphase; numerical simulations; shear band; Soil investigations. Testing; strain localization; Structural analysis. Stresses; surface roughness; Shear test; numerical simulations; Deformation; Interphase; Roughness; Shear strength; discrete element methods; Discrete element method; surface roughness; strain localization; Granular material; Soil test; Formulation; Numerical simulation; Localization; Shear band; Computing method; Interface
• ISSN: 0363-9061; 1096-9853
• DOI: 10.1002/nag.589

Strain localization is closely associated with the stress–strain behaviour of an interphase system subject to quasi‐static direct interface shear, especially after peak stress state is reached. This behaviour is important because it is closely related to deformations experienced by geotechnical composite structures. This paper presents a study using two‐dimensional discrete element method (DEM) simulations on the strain localization of an idealized interphase system composed of densely packed spherical particles in contact with rough manufactured surfaces. The manufactured surface is made up of regular or irregular triangular asperities with varying slopes. A new simple method of strain calculation is used in this study to generate strain field inside a simulated direct interface shear box. This method accounts for particle rotation and captures strain localization features at high resolution. Results show that strain localization begins with the onset of non‐linear stress–strain behaviour. A distinct but discontinuous shear band emerges above the rough surface just before the peak stress state, which becomes more expansive and coherent with post‐peak strain softening. It is found that the shear bands developed by surfaces with smaller roughness are much thinner than those developed by surfaces with greater roughness. The maximum thickness of the intense shear zone is observed to be about 8–10 median particle diameters. The shear band orientations, which are mainly dominated by the rough boundary surface, are parallel with the zero extension direction, which are horizontally oriented. Published in 2007 by John Wiley & Sons, Ltd.