The objective of this work is to evaluate the nonlinear behaviour of beam elements of structural concrete, subjected to asymmetric bending, delimited by two consecutive sections of discontinuity (cracks or open joints), considering the variable adhesion model. For this, two algorithms were developed using the MATLAB tool from the numerical solutions presented herein. The first refers to the equilibrium of sections subjected to asymmetric bending. The second calculates the equilibrium of sections considering the bond-slip effect, maintaining the Bernoulli-Navier hypothesis where perfect adhesion is no longer possible. Two numerical applications (simply supported beams) are used to validate and verify the efficiency of the developed models and algorithms. Results obtained shown that there is a good agreement with the experimental results found in the literature, characterising a good alternative for the evaluation of the nonlinear behaviour of beam elements, when there is a loss of adhesion.

In this paper soil-structure interaction (SSI) effects are investigated while an array of Pressurized Tuned Liquid Column Dampers (PTLCD) is employed for seismic vibration control of buildings. This device represents the most general case of a passive damper, with different reduction options to other control devices obtained by simplifying the involved parameters. Soil conditions considerably affect the control device functioning, because dynamic parameters such as natural frequency, damping factor, and natural modes depend on the soil properties. A simplified mathematical model is developed for the building with multiple degrees of freedom connected to a flexible base. For the time-domain analysis, a computational routine is developed for the linearization of the equilibrium equations of the PTLCD, as well as details for the reduction to the other types of passive dampers. Several numerical examples are selected for the analysis of the damper efficiency in reducing seismic vibration considering SSI. These simulations include Kobe earthquake data, which is applied to the model to evaluate the device performance under different scenarios. It is verified the influence of SSI in the natural frequency and structural response, which is related to the earthquake frequency components. Results confirm that the array of PTLCD's can reduce the vibration amplitudes, being more effective for soils with higher stiffness values.

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A tuned liquid damper (TLD) is a passive control device that transfers kinetic energy from the main structure to a liquid sloshing in a tank. The mechanical description of a sloshing liquid contained in a tank requires an intricate mathematical formulation. An alternative technique describes the TLD dynamic behavior as an equivalent mechanical model comprising a series of pendulums or mass-spring systems attached to the tank walls. To validate this approach, this paper compares the discrete model to experimental results and an analytical solution for a rectangular container attached to a pendulum (pendulum-slosh problem). At first, the fundamental oscillation period of the discrete model, representing a rectangular tank, is compared to experimental data and a classic analytical solution. Finally, we compare the pendulum-slosh problem modeled as a discrete model with the analytical solution and experimental results.

This work aims to verify the influence of the foundation and the reservoir on the dynamic behavior of concrete gravity dams in terms of the natural frequencies, vibration modes for a free vibration analysis; and in terms of maximum displacements and maximum stresses at singular points of the structure for a seismic excitation. The dam-reservoir-foundation interaction was investigated through modal and transient analysis by the finite element method via ANSYS APDL software. For this study, we used a typical Brazilian dam profile and compatible data from a Brazilian earthquake for the seismic excitation. The results showed the influence of the reservoir and the foundation on the natural frequencies in the coupled system, as well as its repercussions on the response of the dam under seismic excitation.