Dragoslav Stojić

Piezoceramic Smart Aggregates for Active Monitoring of Reinforced Concrete Structures

Active structural health monitoring of reinforced concrete civil engineering structures using piezoceramic smart aggregates represent nondestructive evaluation techniques which is characterized by high reliability, wide frequency range, low cost, ease of use, and multifunctionality. Procedure of damage detection is based on wave propagation and used basic piezoelectric effects for smart aggregate actuators and sensors. Represented active monitoring method can detect damage that is not visible with the naked eye, damage that is in inaccessible parts of structures, and damage that cannot be caught by visual inspections. Also, during the measurement, a construction can be undisturbed used which is very important for bridges or industrial production halls. Structural health monitoring is performed by a one-dimensional and two-dimensional damage index formed using wavelet signal analysis and based on energy changes of output sensor signals. In this paper, piezoelectric smart aggregates for structural health monitoring, damage detection, and localization purpose of reinforced concrete civil engineering structures are represented.

Detection of damage to reinforced-concrete structures using piezoelectric smart aggregates

The implementation of active monitoring systems to diagnose damage to reinforced concrete structures using piezoelectric smart aggregates, and based on wave propagation, ranks among the world’s most advanced research activities. Original models, with parametric analysis of the damage index variation problem, depending on the size, position and orientation of cracks, are presented in the paper. Numerical modelling of wave propagation in reinforced concrete is conducted using the explicit finite element method, which is highly effective for this purpose.

Otkrivanje oštećenja armiranobetonskih konstrukcija primjenom piezoelektričnih pametnih agregata

The implementation of active monitoring systems to diagnose damage to reinforced concrete structures using piezoelectric smart aggregates, and based on wave propagation, ranks among the world’s most advanced research activities. Original models, with parametric analysis of the damage index variation problem, depending on the size, position and orientation of cracks, are presented in the paper. Numerical modelling of wave propagation in reinforced concrete is conducted using the explicit finite element method, which is highly effective for this purpose.

Structural vehicle impact loading

In contemporary design, vehicle impact into the structures is paid great attention since they can be dominant, depending on the type of structure. The key issue in the vehicle impact analysis is the proper determination of intensity and way of action of dynamic forces on the structural element and its behavior after the imparted load. The Eurocodes, in the annexes provide recommendations for determination of force intensity depending on mass and velocity of the colliding vehicle. Equivalent static loads causing approximate effects on the structural elements are used as quite approximate and efficient methods. The paper comprises the analysis of deformation of columns having the same characteristics, exposed to impact loads via the equivalent static loads, depending on the stress state in columns, and a comparative analysis has been done.

The design of glued laminated timber footbridge structure according to Eurocodes

The paper presents the conceptual design of the footbridge made of laminated wood. The supporting system of the main bearing elements is made of the laminated wood in the system of arch with three joints and the bridge deck is made of the composite timber concrete structure system. The load patterns for which the dimensions of the supporting bridge structures were adopted (verified according to Eurocode) are presented.