Model for multiblock columns subjected to base excitation

Abstract

Summary A new model is presented for multiblock columns subjected to earthquakes, which contains an impact and an opening model. Both in the impact and in the opening model, all the possible opening configurations are investigated because it was found that in many practical cases, unexpected patterns may occur. The model is purely mechanical: assuming rigid blocks and classical (inelastic) impact. The effect of energy dissipation during impact was investigated. Using our model in accordance with the literature, it was found that monolithic blocks are more vulnerable to overturning than multiblock systems.

Numerical model and dynamic analysis of multi degree of freedom masonry arches

“…To solve the above problem for a multi‐block structure, several approaches are possible, as it was discussed in the study of Ther and Kollár: Analytical solutions due to the complex geometry are feasible only for the four‐hinge, SDOF mechanisms Available FE codes (eg, ANSYS and OpenSees) might be able to calculate the motion of blocks including the deformability of the elements; however, no proper “impact” and “opening” routines are available, hence, these codes must be combined with “opening” and “impact” models.…”

“…Available FE codes (eg, ANSYS and OpenSees) might be able to calculate the motion of blocks including the deformability of the elements; however, no proper “impact” and “opening” routines are available, hence, these codes must be combined with “opening” and “impact” models. We formerly connected OpenSees with the MatLab “opening” and “impact” routines introduced in the study of Ther and Kollár; however, numerical difficulties have been arised because of the high frequency axial vibration of the elements (same numerical difficulties are also mentioned by Vassiliou et al). In theory, the DEM is capable of analyzing the investigated problem, and it is a possible good choice. However, it requires the setting of certain parameters (eg, joint stiffness and damping properties, see the study of DeJong) in such a way that the numerical analyses are close to the experimental results and, furthermore, the number of unknowns is high for a problem, which can be described only by the rotations of the blocks in 2D.…”

“…The goal of the present paper is to establish a physical model, which does not require any setting of the parameters. Recently, a paper on the modeling of multi‐block columns (cantilevers) was published . In the present paper, this model is generalized for arches, and a code is developed to obtain a robust, reliable tool (with a low number of degree of freedom) to calculate the response of planar multi‐block arches.…”

“…The new dynamical model for rocking multi‐block arches is the extension of the multi‐block column model presented in the study of Ther and Kollár . The main difference between them that for arches, the rotations at the interfaces are not independent.…”

“…The modeling of arches must include the possible openings and closings of the interfaces between the blocks, which requires the use of an impact model . The impact of single blocks and multi‐block straight columns was investigated by several researchers, their results were summarized in a paper published recently, and it is not reiterated here. Authors just recall the observation that monolithic blocks are more vulnerable to overturning than multi‐block straight columns with the same overall dimensions …”