Finite-element models for slender, posttensioned masonry walls loaded out-of-plane

Nonlinear finite-element models were developed, verified, and used to simulate the measured response of twelve 3.54m (11.6ft) tall posttensioned masonry walls with 810×100 mm (32×4 in.) cross sections that were tested to failure under uniform lateral loading in a laboratory. Variables included masonry type, wall slenderness, degree of tendon restraint, and prestress magnitude. The force-displacement relations obtained from the experimental tests of the walls were simulated using models developed by using an extended version of the program Dynamic Response Analysis of Inelastic Two-Dimensional Structures (DRAIN-2DX), and the results illustrate the influence of tensile strength, masonry type, magnitude of prestress, and tendon restraint on wall response to out-of-plane lateral loading. The computations indicate that load-displacement response of posttensioned masonry (PTM) walls is influenced by masonry tensile strength and that the stiffness and number of tendon restraints have a direct effect on peak load capacity and postpeak unloading slope. Tendon stress and masonry compression strain responses to applied loading were also investigated using finite-element analysis.