The signature of nonlinearity in the elastic response a specimen to an impingent ultrasonic wave is usually determined through Fourier analysis, which provides low amplitude signals, often below noise level. We suggest here alternative, based on dependence system. Our procedure conceptually simple and easy implement. In addition, it keeps simultaneously into account nonlinear effects phases, amplitudes, frequencies response. sensitivity approach presence proven experimentally.

A new consolidation system for prestressed reinforced concrete (PSRC) beams of girder bridges is presented and evaluated. The consists two arch-shaped steel trusses placed alongside the lateral faces beam to be consolidated. arches develop longitudinally along entire span in elevation using available height PSRC cross-section. characterised by its own external constraints, independent from those serving pre-existing element. efficiency with respect variable parameters examined, focusing on...

Bridges are geometrically complex infrastructures, and their designs usually exhibit significant geometric variations between different structural solutions. The modelling complexity implies a low degree of model reuse in comparable projects; moreover, with the development new technologies design ways, AEC industry often requires computational cost reduction, less time for developments analysis, little-to-zero material waste face environmental emergency. present document proposes generative...

A crucial aspect in damage evaluation of masonry structures is the analysis long-term behaviour and for this reason fatigue has a great influence on safety assessment structures. Acoustic Emission (AE) are very effective non-destructive techniques applied to identify micro macro-defects their temporal evolution several materials. This technique permits estimate velocity ultrasound waves propagation amount energy released during fracture obtain information criticality ongoing process. By...

Historical churches, tall ancient masonry buildings, and bell towers are structures subjected to high risks due their age, elevation, small base-area-to-height ratio. In this paper, the results of an innovative monitoring technique for structural integrity assessment applied a historical tower reported. The emblematic case study Turin Cathedral (northwest Italy) is herein presented. First all, damage evolution in portion structure localized lower levels building described by evaluation...

An innovative laboratory procedure, developed at the Non Destructive Testing Laboratory of Politecnico di Torino, as a preliminary design stage for pre-qualification repair mortars applied to historical masonry buildings is described. Tested are suitable new dehumidified plaster in order stop rising damp effects by capillary action on walls. Long-term delamination occurs frequently consequence not compatible mechanical characteristics mortar. Preventing this phenomenon main way increase...

In this experimental program the main goal is to monitor damage evolution in masonry and concrete structures by Acoustic Emission (AE) signal analysis applying a well-know seismic method. For reason concept of coda wave interferometry applied AE recorded during tests.

Monitoring and assessment of existing infrastructures is gaining attention in nowadays society as aging degradation reduces the residual structural safety.This work aims at providing a competitive procedure for monitoring bearings bridges, based on data analysis coming from use strain gauges.It proposes an unsupervised learning (USL) approach single-valued performance indicator to monitor global behavior critical components viaduct.The exploiting well-known Gaussian Processes analyze...

Orthotropic steel deck (OSD) bridges are lightweight constructions which convenient, especially for the achievement of long spans. Conversely, due to stress concentration in correspondence numerous and unavoidable welded construction details, this bridge typology is prone fatigue cracking under effect cyclic loading with high-stress amplitudes. Existing OSD particularly vulnerable damage accumulation because dated standards adopted at time their design fact that heavy lorries have increased...

An innovative laboratory procedure used as a preliminary design stage for the pre-qualification of strengthening mortars applied to historical masonry buildings is described. In analysis behaviour structures and their constituent materials, increasing importance has been assumed by study long-term evolution deformation mechanical characteristics, which may be affected both loading environmental conditions. Through static fatigue tests on mixed specimens brick-reinforced mortar it possible...

The aim of this work is to analyse the mechanical response masonry specimens under long-term action by means cyclic tests. To end laboratory tests were carried out at Non-Destructive Testing Laboratory Politecnico di Torino. Acoustic Emission technique was employed assess damage evolution, and properties decay in order evaluate extent evolution micro macro-cracking due until structural collapse blocks mortar layers.

Various theories and analytical formulations were implemented exploited in the 1980s 1990s for design of bridge beams or decks curved horizontal plane subjected to out-of-plane loads. Nowadays, Finite Element Method (FEM) is a valid tool analysis structures with complex geometries and, therefore, development sophisticated not needed anymore. However, they are still useful validation FE models. This paper presents case study an existing viaduct built North Italy, aiming compare approaches...

The results of an experimental study concerning the behavior concretes made with recycled aggregates under repeated mechanical and thermal actions are presented. A comparison performances achieved by similar traditional in same working conditions eventually it possible to estimate actual quality durability examined identify limitations their use. laboratory protocol here adopted is suggested as a practical procedure test hardened pre-qualify respect compressive solicitations.

An experimental analysis on a set of strengthened masonry walls has been carried out by means cyclic loading tests in order to simulate the creep effects. The damage evolution specimens reinforced traditional or innovative methods is evaluated Acoustic Emission (AE) technique. AE time dependence during fracture propagation analysed through power law. In addition, frequency used obtain information criticality ongoing process.

The results of an experimental research on plain concrete are presented. non-linear behavior both virgin and damaged samples is investigated by means ultrasonic tests: recent theoretical models, indeed, have pointed out that mono-frequency excitations bring to light such phenomena as harmonic generation sidebands production, which essentially due the material classical or hysteretic non-linearity. estimation components parameters (amplitudes phases) achieved through a signal processing...

Historical churches, masonry towers and bell are structures subjected to high risk, due their age, elevation low base area on height ratio. In this work, an innovative monitoring technique for structural integrity assessment of historical buildings is reported. At the same time, emblematic case study Turin Cathedral Bell tower presented. The damage evolution in tall structure described by evaluation cumulative number AE different parameters able predict time dependence damage. particular,...

The aim of this work is to develop a procedure follow the evolution micro and macro-crack in unreinforced reinforced masonry walls by means Acoustic Emission signal analysis. In particular main goal experimental want be definition characteristic parameter able represents fracture dimension during process. To end laboratory tests were carried out at Non-Destructive Testing Laboratory Politecnico di Torino.