Vibration testing in buildings and safety of their operation

The paper presents the issue of vibrations in residential buildings located near roads. It describes the measurement methodology and criteria for assessing the impact of vibrations generated by passing trucks. The article specifies a method to establish the impact on the operation of the examined facilities and it promotes the idea of employing a Bayesian network to determine probabilistically the level of risk to single-family houses

Deterministic and Probability Analysis of Paper Machine Vibration Impact to the Structure Safety and Human Comfort

This paper describes the probability and sensitivity analysis of the concrete frame and paper machine interaction. On the base of the experimental results, the calculation FEM model was verified. The uncertainties of the loads level, the material properties and other influences following the inaccuracy of the calculated model and numerical methods were considered in the approximation method RSM

Integrated dynamic and thermography investigation of Mallorca cathedral

An integrated investigation of engineering archaeometry was carried out using dynamic identification, dynamic monitoring and Infra-Red (IR) thermography for the study of the dynamic behavior of Mallorca cathedral in Spain. The cathedral is a large historical masonry structure built during 14-16th c. Dynamic identification and monitoring allowed the capturing of eight natural frequencies of the cathedral. IR thermography was used as a complementary inspection technique in the context of a continuous monitoring. Usually, IR thermography is used punctually for the inspection of a part of an inspected structure. Here an alternative was tried as the IR camera was installed for two two-weeks periods in the winter and in the summer of 2011 to monitor the stone surface temperature of a large portion of the cathedral. The correlation between the cathedral natural frequencies and the stone surface temperature of some selected structural elements was investigated and compared with the correlation with the external and the internal temperatures. It was found that the correlation with stone surface temperature was lower than that with external temperature. The study allowed a better understanding of the influence of temperature changes on the structure’s dynamic behavior.Peer ReviewedPostprint (published version

Screening of energy efficient technologies for industrial buildings' retrofit

This chapter discusses screening of energy efficient technologies for industrial buildings' retrofit

A displacement-based design method for medium rise reinforced concrete walls [Un método de diseño basado en desplazamientos para muros de hormigon reforzado de mediana altura]

In displacementbased design methods some demand considerations, starting from the first mode of vibration, are usually made. However, some authors have called the attention on the importance of taking the higher modes into account, due to their influence in the distribution and demand of both, moments and shears along the vertical elements, with significant effects. In this work, the method presented allows to consider, in a practical way, the effect of the higher modes on the seismic response of a structure. The proposal to achieve it, is a simplified model of Three Degree of Fredom developed from a mass concentration of four points equally distant along the building height. This method corresponds to an iterative process, in which the analysis and design procedures are carried out simultaneously, thus, avoiding considerations or suppositions on resistance and ductility values. This method has been applied to the structural walls of a 15storey building. The results obtained show the efficiency of the method in terms of the proposed objectives achievement and the fast converging of the iterative process involved. The effect of the higher modes is extremely noticeable in the distribution of shear stresses and the use of an initial pre-dimensioning involving the reinforcement, allows consistency between the analysis and the structural design

Non-destructive testing on aramid fibres for the long-term assessment of interventions on heritage structures

High strength fibre reinforced polymers (FRPs) are composite materials made of fibres such as carbon, aramid and/or glass, and a resin matrix. FRPs are commonly used for structural repair and strengthening interventions and exhibit high potential for applications to existing constructions, including heritage buildings. In regard to aramid fibres, uncertainties about the long-term behaviour of these materials have often made the designers reluctant to use them in structural engineering. The present study describes simple and non-destructive nonlinearity tests for assessing damage or degradation of structural properties in Kevlar fibres. This was obtained by using high precision measurements to detect small deviations in the dynamic response measured on fibres and ropes. The change in dynamic properties was then related to a damage produced by exposure of the sample to UV rays for a defined time period, which simulated long-term sun exposure. In order to investigate the sensitivity of such an approach to damage detection, non-linearity characterisation tests were conducted on aramid fibres in both damaged and undamaged states. With the purpose of carrying out dynamic tests on small fibre specimens, a dedicated instrumentation was designed and built in cooperation with the Metrology Laboratory of the Department of Electronics at the Politecnico di Torino

A survey study of steering wheel vibration and sound in automobiles at idle

Copyright @ 2009 Engineering Integrity SocietyThis work is supported by Shell Global Solutions UK for their sponsorship of this research as part of the activities of the EFII3 project

Assessment of dynamic and long-term performance of an innovative multi-story timber building via structural monitoring and dynamic testing

Peer reviewedPostprin

Design and simulation of hydraulic shaking table

Recent industrial progress and computational technology made it possible to construct more complex structures. Vibration of these structures due to seismic strength must be measured and proved to prevent them from damage when they are subjected to earthquake. However, the accuracy of estimating the effect of vibrating structures is limited by the mathematical models, which are normally simplified from the actual complex structures. Due to this problem, a study on the development of shaking table is proposed. The main purpose of this study is to obtain the design specifications for a 1-axis (horizontal) hydraulic shaking table with medium loading, which can function primarily as an earthquake simulator and a dynamic structural testing apparatus. The project employs a three stage electrohydraulic servovalve, actuator system complete with hydraulic system as the power and drive unit. Mathematical model for closed loop control experimentation was presented and used to investigate the influence of various parameters on the overall system. The investigation includes the study on the effect of controller gain setting (for PD and AFC), disturbances and system stability. Time domain analysis using computer simulation was conducted to explain and predict the system’s response. Comparison between PD and PD-AFC controllers was done and it was found that latter PD-AFC fulfills the performance and robustness specifications for this project. Other design outcome that limits the change of disturbances on the system was also identified and taken as the framework for real world. This suggests that the next stage in implementation of the designed system can be made for the purpose of an earthquake simulator, since it works very well especially at low frequency level of shakin