Patrick B. Dillon1 and Fernando S. Fonseca2
1)  Project Engineer I, WPD & Associates Consulting Engineers. Inc.
335 Greenbrier Drive, Charlottesville, VA, 22901, USA
2)  Professor, Department of Civil and Environmental Engineering, Brigham Young University
368 Clyde Building, Provo, UT, 84602, USA

Keywords: Strut-and-tie model, numerical modelling, masonry structures, limit analysis, masonry shear-wall.

Abstract. There is a large collection of masonry models due to the highly complex and heterogeneous nature of masonry as a structural material. While the individual masonry components can be considered isotropic at the material level, masonry assemblages are anisotropic at the structural level. These properties of masonry make it difficult to develop models that accurately describe the material behavior for all analysis and design scenarios. One analysis tool that is efficient and reliable is the use of stress fields. Stress fields are based on the lower-bound theorem of the theory of plasticity. Stress fields have been combined with the truss analogy to produce what is known as the strut-and-tie modelling procedure.
This article presents ongoing research that has the objective to develop strut-and-tie modelling procedures for masonry. The presented methodology uses the existing strut-and-tie guidelines for reinforced concrete as starting point and applies that methodology to the modelling of several masonry shear walls with openings. The shear strength predictions from the proposed strut-and-tie modelling methodology are shown to perform well compared to the experimental strengths. This is associated with the ability of the strut-and-tie modelling procedure to account for the geometric particularities of each wall.