Modeling Masonry Shear-Compression: Role of Dilatancy Highlighted

In-plane shear and compression are important modes in masonry walls, both in load bearing structures and in framed structures. By these mechanical actions shear forces caused by wind and earthquakes are resisted. Upon shear-slipping along bed joints, brick units in masonry also undergo upward translation, or dilatancy, causing global volume increase. If this dimensional change is prevented, large compressive stresses may build up, increasing the resistance to slip by the Coulomb-friction nature. If this shear-compression interaction is not modeled correctly, large errors may be made. In the extreme case, unlimited shear resistance may be predicted by computational models. A discrete crack modeling approach for masonry, which captures the shear-compression dilatational behavior realistically, is elaborated. Shear-compression experiments on small masonry specimens as well as 1 m×1 m masonry walls are analyzed as validation.