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Numerical Model for Static and Dynamic Analysis of In-Plane Masonry Infilled Steel Frames

This paper presents simple and sufficiently reliable numerical model for both static and dynamic analysis of 2D in-plane loaded masonry infilled steel frames. Both geometric and material nonlinear effects on structural failure were modelled. Newmark's incremental-iterative algorithm was used for solving dynamic motion equations. The classical elasto-plastic material model for steel in compression and tension was used. Steel failure was defined as a function of strains. Elastic steel behaviour was assumed in unloading. The influence of normal and shear stresses on steel failure was included simultaneously. Micro and macro model for masonry can be used [1]. In the micro model, masonry is modelled at the level of masonry unit and mortar (joints). Contact elements can be used at the joints between masonry units, or between masonry units and mortar. In the macro model, masonry is simulated by representative material with adequate properties. An orthotropic masonry model with different modulus of elasticity, shear modulus, strengths and limit strains in two perpendicular directions can be used. Elasto-plastic behaviour of masonry is assumed in compression and elasto-brittle in tension. Tensile stiffening effect of cracked masonry was modelled, as well as opening and closing of cracks. The influence of shear stresses on masonry failure was also modelled. The model was verified by two experimental tests. In Example 1, an experimentally tested masonry infilled steel frame exposed to horizontal cyclic static force at floor levels was numerically analyzed. In Example 2, an experimentally tested masonry infilled steel frame exposed to dynamic base excitation was numerically analyzed. Results of numerical analysis agreed well to experimental results. However, further testing of the model is necessary.

masonry-infilled steel frames; numerical model; static and

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