No abstract

In this study, the boundary element equations are obtained from the influence functions of a displacement discontinuity in an anisotropic elastic medium. For this purpose, Kelvin fundamental solutions for anisotropic media on infinite and semi-infinite planes are used to form dipoles from singular loads. Various combinations of these dipoles are used to obtain the influence functions of the displacement discontinuity. Boundary element equations are then derived analytically by the integration of these influence functions on a constant element which results in a linear system for unknown displacement discontinuities. The boundary integrals are calculated in closed form over constant elements. The obtained formulation is applied to a number of classical engineering problems.

The aim of this study is to investigate the effect of mortar/unit thickness ratio and unit configuration on the masonry wall behaviour and on masonry structure modelling. Firstly, five wall models with different mortar/unit thickness ratios and with different sizes of units are micro-modelled by using SAP2000 software. The results of these walls are used to obtain the material properties of anisotropic macro-models in vertical and horizontal directions. Secondly, a sample unreinforced masonry structure is simulated by the same software using anisotropic material properties. Earthquake loading is applied following the Turkish seismic code. Responses of these five structure models are compared with each other and also with their isotropic modelled counterparts. It is observed that isotropic modelling overestimates the rigidity of the structure around 3-5% for low mortar/unit thickness ratios, but underestimates the rigidity around 5-7% for high mortar/unit thickness ratios

The aim of this study is to investigate the effect of mortar/brick thickness ratio, brick configuration on the masonry stresses and on masonry structure modelling. Different mortar/brick thickness ratios are micro-modelled by using stress-strain relationship. The results of these models are used to obtain the material properties of anisotropic macro-models in vertical and horizontal directions. The sample unreinforced masonry structures are simulated by the SAP2000 software using anisotropic material properties. In general masonry structures are composite materials that consists of brick and mortar. The main goal in modelling is to simulate a model that behaves close to the real structure as much as possible. Micro-modelling of masonry structure by considering its components individually is more realistic but not practical for large scale structures. In order to overcome this problem, macro-modelling is used in literature. Macro-model is obtained by smearing out the material properties of the micro-model to an anisotropic continuum material. Currently, most engineers simply analysis masonry structures with isotropic modelling in practice. However, presence of head and bed mortar joints in the construction of masonry causes the masonry to be anisotropic. Anisotropic modelling of a large scale structure does not need unreasonable effort as in micro-modelling and can be used instead of isotropic modelling easily in practice. Considering the horizontal and vertical loads in the plane, some wall types with rectangular cross-section, rectangular and arches cross-sections cavities were modeled as anisotropic and the effect of anisotropic material was investigated. In terms of displacements, an isotropic model and anisotropic models were found to be close to each other. However, when examined in terms of stresses, the maximum and minimum stresses in the masonary structure were changed.

As is known, the masonry structures, together with the main structural materials, such as stone or brick, consist of mortar material which serves as the adhesive between these materials. In general, the mechanical properties of brick, stone and mortar materials are different. However, they have been used throughout history and have been the unchanging materials used in masonry structures. The structural walls are formed by the heterogeneous joining of two materials with different mechanical properties. However, these heterogeneous structural elements are generally considered homogeneous for ease of calculation. In this study, the effects of different joint thicknesses on masonry structures on minarets structure were investigated. Changes in structure behaviour were investigated by using different material properties to a masonry minaret structure. By examining these differences, the effect of isotropic or anisotropic modelling on the result, the effect of mortar thickness on the result was compared and the results were interpreted.