Out-of-plane behavior of confined masonry walls with aspect ratios greater than one

An experimental study on the out-of-plane behavior of confined masonry walls is presented. Four confined walls with aspect ratios greater than one were tested in the laboratory. Walls were subjected to combined axial and out-of-plane uniform loads. The variables studied were the aspect ratio and the axial compressive stress of walls. It was observed that the out-of-plane strength of walls increased as the aspect ratio or the axial compressive stress increased. Failure of walls was associated with crushing of masonry. Analytical out-of-plane strength of walls was determined using the yielding line, failure line, modified yielding line, compressive strut and bidirectional strut methods. It was concluded that the experimental out-of-plane strength of walls was best predicted with the bidirectional strut method.

Vibration of Tensegrity Stucture by using SEM

A tensegrity structure is a structure which consists both of compressive and tensile elements without being restrained at the boundaries. The self-equilibrium state inside the tensegrity structure is the condition that builds the structure without any boundary condition necessity. The conventional Eigensystem solver cannot deal with this kind of structure since there are rigid body motions in the governing equations. The exact dynamic solution of tensegrity structure problems can only be obtained by using the frequency-dependent dynamic method. In this study, the free vibrational characteristics of a tensegrity structure which is modeled by a combination of the compressive strut and tensile cables elements are solved by using the Spectral Element Method (SEM). Natural frequencies of the tensegrity are tracked by using the Wittrick-Williams algorithm. Numerical calculations are given to show the effectiveness, efficiency, and accuracy of the SEM in solving the axially vibrating members of the tensegrity structures.

Bidirectional strut method: out-of-plane strength of confined masonry walls

An analytical method to determine the out-of-plane strength of confined masonry walls is developed. The method is called the “bidirectional strut method.” Walls with and without openings subjected to combined out-of-plane and axial loads are considered. The method is based on two-way arching action. Masonry compressive strut forces are transferred eccentrically to the concrete confining elements. Flexural and torsional effects, together with the variation of displacements along these elements, are considered. Analytical strengths of confined walls are determined using this method. These strengths are compared with experimental and other analytical strengths. A sensitivity analysis of the strength is carried out considering different variables. It is concluded that the bidirectional strut method accurately predicts the strength of the walls studied. The main variables that affect the strength are the wall aspect ratio, wall slenderness ratio, and the stiffness of the confining elements.