Aleksandar Pavic

Aleksandar Pavic
University of Exeter | UoE · College of Engineering, Mathematics and Physical Sciences

BSc MSc PhD

About

190
Publications
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4,288
Citations

Publications

Publications (190)
Conference Paper
Short-term ambient vibration testing (AVT) was carried out on two tall timber buildings (TTBs) at different construction’s stages. The objectives of these tests were to evaluate key dynamic properties (natural frequencies and mode shapes) under predominantly ambient wind dynamic loading. The identified key dynamic properties were estimated experime...
Conference Paper
This paper describes a novel and oven-controlled crystal oscillator (OCXO) high-precision synchronised wireless data acquisi-tion system for modal testing of large structures. The system was used for the first time for a rare FRF-based modal testing ofa full-scale multi-storey building in operation. National Instruments CompactRIO and LabVIEW were...
Conference Paper
Full-text available
Wind-induced dynamic excitation is becoming a governing design action determining size and shape of modern Tall Timber Buildings (TTBs). The wind actions generate dynamic loading, causing discomfort or annoyance for occupants due to the perceived horizontal sway – i.e. vibration serviceability failure. Although some TTBs have been instrumented and...
Conference Paper
This paper describes an experimental validation of a novel FRF-based modal testing system designed to measure experimentally sway modes of tall timber and other building structures. The test uses a set of synchronised electrodynamic shakers and oven-controlled crystal oscillator (OCXO) high-precision synchronised wireless accelerometers for simulta...
Conference Paper
Wind-induced dynamic excitation is becoming a governing design action determining size and shape of modern tall timber buildings (TTBs). The wind actions generate dynamic loading, causing discomfort or annoyance for occupants due to the perceived horizontal sway – i.e. vibration serviceability failure. Although some TTBs have been instrumented and...
Article
Over the last two decades, office floors have been built progressively lightweight with increasing spans and slenderness. Therefore, vibration performance of office floors due to walking dynamic loads is becoming their governing design criterion, determining their size and shape, and therefore overall weight and embodied energy of the building. To...
Article
Full-text available
Background: Wearable inertial sensors have grown in popularity as a means of objectively assessing fall risk. This review aimed to identify gait and posture differences among older adult fallers and non-fallers which can be measured with the use of wearable inertial sensors. In addition to describing the number of sensors used to obtain measures,...
Article
Full-text available
The key UK design guidelines published by the Concrete Society and Concrete Centre for single human walking excitation of high-frequency floors were introduced more than 10 years ago. The corresponding walking force model is derived using a set of single footfalls recorded on a force plate and it features a deterministic approach which contradicts...
Article
Full-text available
Monitoring natural human gait in real-life environments is essential in many applications, including quantification of disease progression, monitoring the effects of treatment, and monitoring alteration of performance biomarkers in professional sports. Walking ground reaction forces are among the key parameters necessary for gait analysis. However,...
Article
Full-text available
Continuous monitoring of natural human gait in real-life environments is essential in many applications including disease monitoring, rehabilitation, and professional sports. Wearable inertial measurement units are successfully used to measure body kinematics in real-life environments and to estimate total walking ground reaction forces GRF(t) usin...
Article
Full-text available
Monitoring natural human gait in real-life environment is essential in many applications including quantification of disease progression, and monitoring the effects of treatment and alteration of performance biomarkers in professional sports. Nevertheless, reliable and practical techniques and technologies necessary for continuous real-life monitor...
Article
The interaction of walking people with large vibrating structures, such as footbridges and floors, in the vertical direction is an important yet challenging phenomenon to describe mathematically. Several different models have been proposed in the literature to simulate interaction of stationary people with vibrating structures. However, the researc...
Conference Paper
There is a continuous development in the facilities used for experimental measurements of human-induced vibrations due to walking of people in real-life structures. These facilities can be classified into three categories: 1.systems used to measure walking forces,2.systems used to measure structural dynamic properties and vibration responses and3.e...
Article
Full-text available
For vibration serviceability of floors, current design guidelines adopt different criteria to assess vibration levels due to human walking dynamic excitation. Whatever the adopted criterion is, it requires a quantified vibration response of the structure. This quantification could be achieved following either a time- or a frequency-domain approach...
Article
Full-text available
Despite the intensive research that has focused on the dynamic interaction between walking people and slender footbridges, this phenomenon has never been investigated for floor structures. For lightweight floors having mass of 150 kg/m2 or less, where they have relatively low modal masses and damping ratios, this interaction is expected to be more...
Article
Full-text available
When Vibration approached me to be its founding Editor-in-Chief, it was explained to me that the key selling points of this new online journal would be as follows [...]
Article
Full-text available
Measurement of the ground reaction forces (GRF) during walking is typically limited to laboratory settings, and only short observations using wearable pressure insoles have been reported so far. In this study, a new proxy measurement method is proposed to estimate the vertical component of the GRF (vGRF) from wearable accelerometer signals. The acc...
Article
Full-text available
Monitoring natural human gait in real-life environments is essential in many applications, including quantification of disease progression, monitoring the effects of treatment, and monitoring alteration of performance biomarkers in professional sports. Nevertheless, developing reliable and practical techniques and technologies necessary for continu...
Chapter
Dynamic interaction between walking humans and vibrating flexible structures is one of the main challenges when simulating human-induced vibrations. To account for this interaction, several mass-spring-damper (MSD) models featuring different parameters have recently been proposed. This paper compares the performance of six experimentally-based MSD...
Chapter
For vibration serviceability of floors, current design guidelines propose different force models to represent human walking on structures. Those models have been derived based on many assumptions to simplify the real force induced by human walking. One of those assumptions states that the force is assumed periodic. Other simplification is that the...
Article
Full-text available
Predicting the effect of walking traffic on structural vibrations is a great challenge to designers of pedestrian structures, such as footbridges and floors. This is mainly due to the lack of adequate design guidelines , which in turn can be blamed on poor research findings. Even the fundamental data are very rare and limited. This study proposes a...
Article
Full-text available
The increasing number of reported vibration serviceability problems in newly built pedestrian structures, such as footbridges and floors, under walking load has attracted considerable attention in the civil engineering community over the past two decades. The key design challenges are: the inter- and intra-subject variability of walking people, the...
Conference Paper
Human induced vibration is one of the essential design considerations for the design of high-frequency building floors supporting vibration sensitive equipment and processes, such as precision laboratories and operating theatres in hospitals. For this purpose, the model derived by Arup, and adopted by the current UK Concrete Society and the Concret...
Article
Full-text available
The dynamic interactions of falling human bodies with civil structures, regardless of their potentially critical effects, have sparsely been researched in contact biomechanics. The physical contact models suggested in the existing literature, particularly for short-distant falls in home settings, assume the human body falls on a “ rigid ” (not vibr...
Article
Full-text available
Realistic simulation of the dynamic effects of walking pedestrians on structures is still a considerable challenge. This is mainly due to the inter- and intrasubject variability of humans and their bodies and difficult-to-predict loading scenarios, including multipedestrian walking traffic and unknown human-structure interaction (HSI) mechanisms. O...
Article
Cold-formed steel (CFS) sections are becoming an increasingly popular solution for constructing floors in residential, healthcare and education buildings. Their reduced weight, however, makes them prone to excessive vibrations, increasing the need for accurate prediction of CFS floor modal properties. By combining experimental modal analysis of a f...
Article
Interaction of walking people with vibrating structures is known to be an important yet challenging phenomenon to simulate. Despite of its considerable effects on the structural response, no properly formulated and experimentally verified model currently exists to simulate this interaction in the vertical direction. This work uses a single-degree-o...
Conference Paper
The approach used to estimate dynamic properties of civil engineering structures normally comprise numerical modelling and much less frequently - experimental modal analysis. Hence, the work presented in this paper focuses on the later approach. The multi-input multi-output (MIMO) modal test for civil engineering structures is not commonly used and...
Chapter
The approach used to estimate dynamic properties of civil engineering structures normally comprise numerical modelling and much less frequently—experimental modal analysis. Hence, the work presented in this paper focuses on the later approach. The multi-input multi-output (MIMO) modal test for civil engineering structures is not commonly used and i...
Article
Interaction of walking people with structures is known to be an important yet challenging when simulating vertical response of the structure due to walking excitation. Despite of its critical effects on structural response, no properly formulated and experimentally verified model exist to simulate effects of walking pedestrians on structures. In th...
Article
Full-text available
Nonstructural vertical partitions and cladding can have a significant effect on the vibration serviceability of floor systems. A typical modern office building, consisting of steel–concrete composite floor systems, was created to investigate the potential beneficial effects of integrating nonstructural partitions into structural floor systems to re...
Article
This paper provides a critical overview of available technology and facilities for determining human-induced dynamic forces of civil engineering structures, such as due to walking, running, jumping and bouncing. In addition to traditional equipment for direct force measurements comprising force plate(s), foot pressure insoles and instrumented tread...
Conference Paper
Full-text available
Ambient and forced excitation test techniques are both widely used to dynamically identify civil engineering structures. Two floor levels of a newly constructed building, the Charles Institute at University College Dublin, were tested using both techniques. Both floor designs were identical although the layout of partitions above and below each wer...
Book
Topics in Dynamics of Civil Structures, Volume 4: Proceedings of the 31st IMAC, A Conference and Exposition on Structural Dynamics, 2013, the fourth volume of seven from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied...
Chapter
Full-text available
Ambient and forced excitation test techniques are both widely used to dynamically identify civil engineering structures. Two floor levels of a newly constructed building, the Charles Institute at University College Dublin, were tested using both techniques. Both floor designs were identical although the layout of partitions above and below each wer...
Article
Increasing vibration serviceability problems of modern pedestrian structures have drawn researchers’ attention to detailed modelling and assessment of walking-induced vibration on floors and footbridges. Stochastic nature of human walking and unknown mechanisms of their interaction with the structure and surrounding environment, make it difficult t...
Article
It is commonly known that full-height non-structural partitions of a fitted out floor structure affect its dynamic properties, with increase in floor mass and modal damping being commonly quoted in floor design guidelines. As a consequence, it is generally accepted that the non-structural elements usually reduce the response of floors to walking ex...
Article
This paper presents a vision for the future monitoring systems which will become normal requirements for management of bridges as key objects of national infrastructure in the UK and elsewhere. Rather than being pushed by authorities and legislation, we expect that bridge managers will recognize the clear business cases for investing in well-design...
Conference Paper
Vibration serviceability of structures for human occupancy has become an important part of the design of slender civil engineering structures such as footbridges. In the past decades, a considerable amount of research has been carried out within the field and international codes of practice and state-of-the-art design guidelines been improved consi...
Conference Paper
With increasing importance of vibration serviceability limit state in floor design, especially in relation to human induced dynamic loading, there is a need for defining reliable models of pedestrians that reflect normal usage of the structure. Modelling the walking loading for individual pedestrians has rapidly advanced over the past decade. Howev...
Article
This paper presents a mathematical model to generate synthetic narrow band vertical force signals due to individuals walking. The model is fitted to a unique database comprising many directly measured vertical walking force time histories due to diverse population of human test subjects walking on an instrumented treadmill at a range of speeds, yie...
Article
Full-text available
Recent vibration serviceability problems of many structures have drawn researchers' attention to the walking-induced vibration modelling and assessment of floors and footbridges. Stochastic nature of human-induced vibration and its dependency on numerous conditions significantly reduce the accuracy of the current non-stochastic design procedures an...
Article
This paper describes the modal testing and in situ vibration monitoring of a high profile UK stadium during 2004 and 2005, including multiple concerts and sports events. The paper explains how current design guides pertaining to crowd dynamic loading of grandstands can be practically implemented using experimental modal data or finite element (FE)...
Chapter
A mathematical modelling procedure has been developed to generate synthetic vertical force signals induced by a single person jumping. The ability to replicate much of the temporal and spectral features of real jumping loads gives this model a definite advantage over the conventional half-sine models coupled with Fourier series analysis. This inclu...
Article
This paper is a critical review of information pertinent to the behaviour of stadia structures subjected to dynamic crowd loading. It is intended to introduce and explain key concepts in the field as well as summarise the development of current guidance and methods for modelling and assessing crowd occupancy.The review is structured by presenting a...
Chapter
State-of-the-art facilities for measuring bouncing and jumping ground reaction forces (GRFs) comprise typically equipment for direct force measurement, i.e. single or multiple floor-mounted force plates. Artificial laboratory conditions and constraints imposed by the direct measurement systems, such as small measuring area of a force plate, can hav...
Article
The continuing trend towards the design of more slender, lighter, and livelier footbridges has created new challenges that are not properly addressed in a number of widely used codes of practice in Europe and Canada. Recent research into vibration serviceability of slender structures under human-induced dynamic loading suggests that improvements to...
Article
Full-text available
Due to their slenderness, many modern footbridges may vibrate significantly under pedestrian traffic. Consequently, the vibration serviceability of these structures under human-induced dynamic loading is becoming their governing design criterion. Many current vibration serviceability design guidelines, concerned with prediction of the vibration in...
Article
Due to their slenderness, many modern footbridges may vibrate significantly under pedestrian traffic. Consequently, the vibration serviceability of these structures under human-induced dynamic loading is becoming their governing design criterion. Many current vibration serviceability design guidelines, concerned with prediction of the vibration in...
Article
Full-text available
A mathematical model has been developed to generate stochastic synthetic vertical force signals induced by a single person jumping. The model is based on a unique database of experimentally measured individual jumping loads which has the most extensive range of possible jumping frequencies. The ability to replicate many of the temporal and spectral...
Article
The research into modeling walking-induced dynamic loading and its effects on footbridge structures and people using them has been intensified in the past decade after some high profile vibration serviceability failures. In particular, the crowd induced loading, characterized by spatially restricted movement of pedestrians, has kept attracting atte...
Article
Pedestrian bridges are increasingly becoming landmark structures designed to promote a modern vibrant image of their surrounding landscape. Designs are becoming more daring; spans are increasing and becoming more slender and the use of lightweight materials is more prevalent. The net result is that it is often the serviceability limit state, rather...
Article
State-of-the-art facilities for measuring bouncing and jumping ground reaction forces (GRFs) comprise typically equipment for direct force measurement, i.e. single or multiple floor-mounted force plates. Artificial laboratory conditions and constraints imposed by the direct measurement systems, such as the small measuring area of a force plate, can...
Conference Paper
Vibration serviceability of building floors is becoming a governing design criterion for many open plan building floors. To make correct decisions about floor vibration performance, calculating only the highest vibration response of the floor is not sufficient anymore. Because of the considerable complexity of the problem and shortcomings of practi...
Article
A mathematical modelling procedure has been developed to generate synthetic vertical force signals induced by a single person jumping. The ability to replicate much of the temporal and spectral features of real jumping loads give this model a definite advantage over the conventional half-sine models coupled with Fourier series analysis. This includ...
Article
Full-text available
Because of inherent variability in all human cyclical movements, such as walking, running and jumping, data collected across a single cycle might be atypical and potentially unable to represent an individual's generalized performance. The study described here was designed to determine the number of successive cycles due to continuous, repetitive co...
Article
Full-text available
A novel mathematical modeling has been proposed to generate synthetic vertical force signal induced by a single person jumping. This model can replicate much of the temporal and spectral features of the real jumping loading more reliably than the existing half-sine models coupled with Fourier series analysis. This includes lack of symmetry of indiv...
Article
Full-text available
Dynamic forces induced by humans walking change simultaneously in time and space, being random in nature and varying considerably not only between different people but also for a single individual who cannot repeat two identical steps. Since these important aspects of walking forces have not been adequately researched in the past, the corresponding...
Article
Full-text available
This paper presents a combined experimental and numerical investigation of the modal properties of two full-scale and nominally identical steel–concrete composite floors. The floors were one above the other in the same fully operational multi-storey building. Both floors accommodated open-plan as well as partitioned offices. Multi-input-multi-outpu...
Article
A discussion with regards on the recent tests conducted on several Gothic churches which aims on improving the necessary knowledge needed on finite element (FE) models of the structure is presented. A focus will be given on the illustration of the typical modal testing results from complex vaulted Gothic churches, as well as to indicate the typical...
Article
Full-text available
Slender floor structures are becoming increasingly prone to excessive vibration due to human-induced walking excitation. To prevent discomfort of floor occupants and/or malfunctioning of sensitive equipment, it is necessary to have a reliable means of estimating floor vibration in the design phase. For accurate estimation of the floor vibration, bo...
Conference Paper
Full-text available
Civil engineering structures that accommodate pedestrians, such as footbridges and floors, could be exposed to excessive vibrations under walking-induced dynamic excitation. Since humans are quite sensitive vibration receivers, this situation leads to pedestrians' interaction with the structure. For laterally moving structure, the interaction often...
Conference Paper
Full-text available
Slender structural forms are common in modern footbridge design. This slenderness has increased the potential for excessive vibrations in as-built structures. Popular design codes of practice, such as British Standard BS 5400, no longer provide adequate guidance for designers assessing vibration serviceability of footbridges. The method used in BS...
Article
Full-text available
State-of-the-art facilities for measuring human-induced dynamic forces comprise typically equipment for direct force measurement, made of a single or several force plates and an instrumented treadmill mounted on a rigid laboratory floor. Artificial laboratory conditions and constraints imposed by the direct measurement systems, such as small measur...
Book
Recommendations, guidelines, codes, design tools,. Practical experience - case studies
Article
Full-text available
This article describes a combined experimental and analytical approach to investigating modal properties of beam and block (B&B) building floors. A rarely performed dynamic testing of a representative sample of four nominally identical B&B open plan suspended ground floors in a real-life building has been carried out using state-of-the-art modal te...
Article
The behavior of humans jumping and bobbing on flexible structures has become a matter of some concern for both structural integrity and human tolerance. The issue is of great importance for a number of structure types including stadia terraces. A unique test rig has been developed for exploring the forces, accelerations, and displacements that occu...
Article
Frequently, office floors are developed as a result of retrofitting and upgrading of existing buildings. To check the vibration serviceability of such floors, an experimental approach where the evaluation is done by vibration measurements of the full-scale floor structures is used. An advanced, but practicable, experimental procedure for assessing...
Article
Modal testing is usually performed on existing office floor structures. Regardless of the motivation for performing the model tests, it is clearly desirable to ensure that modal test data of the highest possible quality is acquired on site in the minimum amount of time. In general, the entire process of performing a modal test is decomposed into fo...
Article
Two of the currently most common excitation methods for modal testing on building floor structures are by using hammer impact or shaker excitation. However, the advantages and disadvantages in the literatures devoted to these techniques do not apply when testing large scale building floor structures. In this context, an outline of these two modal t...