Dynamic response analysis of multi-storey building to a non-uniform excitation

In this paper the dynamic behaviour of multi-storey steel building is presented. The structure was subjected to a real, strong mining shock. During the analysis the time history analysis and the spectrum method were taken into account. The time history analysis concerns the uniform and non-uniform model of ground motion. A wave velocity of 300m/s was taken under consideration. The kinematic excitation was applied on the structure as support accelerations. The stress at selected points of structure were compared for all methods. The region nearby the connections was analysed particularly. The state of stress for connection zones was recognized

Dynamic behaviour of a concrete building under a mainshock–aftershock seismic sequence with a concrete damage plasticity material model

The aim of this paper was to investigate the dynamic response of a concrete structure subjected to a mainshock–aftershock seismic sequence. In the dynamic analysis, three components of the registered mainshock and aftershock were taken into account. The peak ground accelerations of about 0.5 g were assumed for both shocks. A one-storey shed was modelled with the ABAQUS software to represent a large concrete structure under the repeated earthquakes. For proper characterization of concrete structure behaviour under the sequence of shocks, a concrete damage plasticity model was assumed as a constitutive model of concrete. The obtained results indicate that aftershocks can have considerable effect on dynamic behaviour of concrete structures in terms of enlarging zones affected by irreversible strains or additional damage evolution. The analysis revealed that aftershocks, which are usually not as strong as mainshocks, may result even in total loss of concrete material strength while performing in mainshock–aftershock seismic sequences

Dynamic response analysis of multi-storey building to a non-uniform excitation

In this paper the dynamic behaviour of multi-storey steel building is presented. The structure was subjected to a real, strong mining shock. During the analysis the time history analysis and the spectrum method were taken into account. The time history analysis concerns the uniform and non-uniform model of ground motion. A wave velocity of 300m/s was taken under consideration. The kinematic excitation was applied on the structure as support accelerations. The stress at selected points of structure were compared for all methods. The region nearby the connections was analysed particularly. The state of stress for connection zones was recognized

Full-Scale Experimental and Numerical Investigations on the Modal Parameters of a Single-Span Steel-Frame Footbridge

In this work, an examination on the modal properties of a single-span steel-frame footbridge is presented. The footbridge is situated in Jawornik (Lesser Poland). The footbridge is symmetrical since its main structure consists of two steel frames of the same shape. The boundary conditions for both frames are the same as well. The study was completed on the basis of numerical as well as experimental investigations. For finite element (FE) analysis, a 3-D model of the single-span steel-frame footbridge was created. For the experimental study, a research scheme for in situ tests was developed. Three kinds of excitation techniques were used during the in situ tests: shock excitation, operational vibration, and slow sine sweep testing. Different functions that estimate natural frequencies, i.e., the power spectral density function (PSD) and the frequency response function (FRF), were applied. The modal assurance criterion (MAC) was used as a mathematical tool for the verification of the mode shapes of natural vibrations obtained in experimental and numerical ways. Good compatibility was recognized between the results obtained for experimental and numerical procedures in terms of both the natural frequency and the mode of vibration. The identified and verified values of the five consecutive natural frequencies of the footbridge were smaller than 5 Hz, but they were recognized as being located outside the frequency range defined as having “maximum risk of resonance". The numerical and experimental modal analysis revealed that all modes corresponding to the natural frequencies from the 0–5 Hz range have both a symmetrical and an anti-symmetrical nature. In particular, the first vertical mode, which can play a central role from the serviceability of the footbridge point of view has a symmetrical shape. The results of the research might be applicable to the dynamic study of the structure type considered in the analysis, i.e., for the dynamic assessment of a single-span steel-frame footbridge with a relatively large mass as well as stiffness. The investigation proved that ambient vibration modal experiments are enough for the experimental investigation of the modal properties of the structure

Dynamic assessment of a cable-stayed footbridge under earthquake sequence using a concrete damage plasticity model (CDP)

In this paper, the investigation of the dynamic response of a cable-stayed footbridge with steel reinforced concrete deck to foreshocks, a mainshock and an aftershock seismic sequence is delivered. For the aim of the study the finite element (FE) model was prepared with the ABAQUS/Standard software program. The representative seismic events with three components were taken into account in the numerical simulation. For the evaluation of seismic-induced damages in reinforced concrete deck of the footbridge, the concrete damage plasticity (CDP) model was applied

Dynamic assessment of a cable-stayed footbridge under earthquake sequence using a concrete damage plasticity model (CDP)

In this paper, the investigation of the dynamic response of a cable-stayed footbridge with steel reinforced concrete deck to foreshocks, a mainshock and an aftershock seismic sequence is delivered. For the aim of the study the finite element (FE) model was prepared with the ABAQUS/Standard software program. The representative seismic events with three components were taken into account in the numerical simulation. For the evaluation of seismic-induced damages in reinforced concrete deck of the footbridge, the concrete damage plasticity (CDP) model was applied

Assessment of human-induced vibrations of a cable-stayed footbridge

The primary purpose of this research is the evaluation of human-induced vibrations of a cable-stayed footbridge. The cable-stayed pedestrian bridge with total length of the span equal to 46.90 m located in Czestochowa (Southern Poland) was chosen as a case study. The footbridge consists of two spans (21.10 m and 25.80 m). A three-dimensional (3D) finite element (FE) model of the footbridge was prepared with the ABAQUS software program. The dynamic properties of the structure, i.e. its natural frequencies, modes shapes and damping ratios, were estimated on the basis of the in situ tests results as well as numerical analysis. For the validation of the modal models the modal assurance criterion (MAC) theory was applied. In the next stage of the investigation the dynamic response of the structure to human-induced loading was evaluated. Finally, the vibration comfort criteria for the footbridge were checked

Seismic performance of a masonry arch viaduct subjected to foreshocks and a mainshock

The main objective of this work is to present the results of seismic numerical investigation which was conducted for a masonry arch viaduct. The viaduct which was chosen as a case study, was subjected to foreshock-mainshock sequence. For the numerical evaluation a 3D finite element model (FEM) of the structure was assembled with the ABAQUS/Standard software program. In the numerical simulations a Barcelona Model (BM) was applied as a constitutive material model to represent nonlinear behaviour of the masonry arches of the investigated viaduct under the seismic actions. Taken into consideration the results of calculations the evident nonlinear behaviour of the masonry arches was detected under the earthquakes. The plastic strains as well as the cracking were achieved in some areas of the arches of the viaduct after seismic foreshock-mainshock sequence. Also proposed methodology for strengthening and monitoring of the structure of the viaduct in the future

Dynamic response of a cable-stayed footbridge to high-energy mining tremors

In this work an analysis of the dynamic response of a cable-stayed footbridge to mining tremors typical for two main regions of mining activity in Poland, i.e. the Legnica-Glogow Copper District (LGCD) and the Upper Silesian Coal Basin (USCB) is presented. For analysis, a 3-D finite element (FE) model of the structure was created in the ABAQUS/Standard software program. As a final result, the dynamic responses of the footbridge to the typical mining tremors were delivered. For this stage, the numerical simulations were conducted with the non-uniform kinematic excitation as well as with the uniform kinematic excitation. Finally, the evaluation of two calculation approaches was also made for the studied structure