Search results for "structural"

A Boundary Element Formulation for Modelling Structural Health Monitoring Applications

2015

In this paper, a boundary element formulation for modelling pitch-catch damage detection applications is introduced. The current formulation has been validated by both finite element analyses and physical experiments. Comparing to the widely used finite element method, the current formulation does not only use less computational resources, but also demonstrates higher numerical stability. doi: 10.12783/SHM2015/221

Modal Analysis of a Reinforced Concrete Frame in Various States of Damage

2005

The purpose of this paper is to report selected results of an experiment in which two, natural size r/c frames were put on shaking table and subjected to a sequence of seismic excitations with increasing intensity interlaced with low level, diagnostic tests. The shaking table experiment aimed at working out new methodology for monitoring vibrations of r/c structures to assess their state. Characteristic decrease of natural frequencies and increase of structural damping was observed and analyzed in detail. It was interesting to note 20 per cent drop in natural frequencies prior to visual detection of any cracks.

Vulnerability of a Damaged Bridge Abutment in a Seismic Area

2018

The case of the abutment of a motorway urban viaduct damaged by human intervention is presented. Built in the 1960s, it lies in a critical seismic area and the human-induced damage involved the elements of the abutment foundation. The structure is geometrically complex and the evaluations of its structural safety were carried out by applying Italian codes from different times: those concerning the time of construction, those of a recent past (1996), and those of the present (2008), inspired by Eurocodes. A comparison between the safety checks performed and the requirements of all these codes is presented and discussed, especially regarding safety coefficients after the damage was done. Two …

An integral equation for damage identification of Euler-Bernulli beams under static loads

2004

A Strain Sensing Structural Health Monitoring System for Delaminated Composite Structures

2012

Structural Health Monitoring (SHM) for composite materials is becoming a primary task due to their extended use in safety critical applications. Different methods, based on the use of piezoelectric transducers as well as of fiber optics, has been successfully proposed to detect and monitor damage in composite structural components with particular attention focused on delamination cracks.In the present paper a Structural Health Monitoring model, based on the use of piezoelectric sensors, already proposed by the authors for isotropic damaged components, is extended to delaminated composite structures. The dynamic behavior of the host damaged structure and the bonded piezoelectric sensors is m…

UVPAR: fast detection of functional shifts in duplicate genes.

2006

Abstract Background The imprint of natural selection on gene sequences is often difficult to detect. A plethora of methods have been devised to detect genetic changes due to selective processes. However, many of those methods depend heavily on underlying assumptions regarding the mode of change of DNA sequences and often require sophisticated mathematical treatments that made them computationally slow. The development of fast and effective methods to detect modifications in the selective constraints of genes is therefore of great interest. Results We describe UVPAR, a program designed to quickly test for changes in the functional constraints of duplicate genes. Starting with alignments of t…

Transglutaminase and polyamine dependence of effector functions of human immunocompetent cells

1982

AbstractThe effects of the transglutaminase inhibitor dansyl cadaverine (DC) and the polyamine antagonist methyl glyoxal-bis-(guanylhydrazone) (MeGbG) on the response of lymphocytes towards allogeneic and lectin stimulation and on the zymosan-induced chemiluminescence of neutrophilic granulocytes was studied. Application of DC resulted in dose-dependent suppression of chemiluminiscence and lymphocyte proliferation; no difference of inhibitory potential occurred with variation of incubation time in the latter system. MeGbG was inactive in granulocytes, but inhibited lymphocyte proliferation; its effect increased with time. The experiments provide further evidence for the importance of transg…

Analyzing big datasets of genomic sequences: fast and scalable collection of k-mer statistics

2019

Abstract Background Distributed approaches based on the MapReduce programming paradigm have started to be proposed in the Bioinformatics domain, due to the large amount of data produced by the next-generation sequencing techniques. However, the use of MapReduce and related Big Data technologies and frameworks (e.g., Apache Hadoop and Spark) does not necessarily produce satisfactory results, in terms of both efficiency and effectiveness. We discuss how the development of distributed and Big Data management technologies has affected the analysis of large datasets of biological sequences. Moreover, we show how the choice of different parameter configurations and the careful engineering of the …

Monitoring road pavement performance through a novel data processing approach, accelerated pavement test results

2020

This research presents a novel performance-based interpretation method for continuous monitoring of pavement condition through the use of piezoelectric sensors. The objective of this study is to validate the compressed cumulative loading event approach, implemented in a previously developed piezoelectric sensor, for detecting subsurface fatigue cracking through full-scale accelerated pavement testing. A piezo-electric film of polyvinylidene fluoride is used to harvest the microstrain energy induced by the traffic loading at the surface. Epoxy is used to protect the sensor following a H-shape packaging. Piezoelectric sensors were exposed to approximately 1.0 million load repetitions between …

Assessing the format and content of journal published and non-journal published rapid review reports: A comparative study

2020

Background As production of rapid reviews (RRs) increases in healthcare, knowing how to efficiently convey RR evidence to various end-users is important given they are often intended to directly inform decision-making. Little is known about how often RRs are produced in the published or unpublished domains, and what and how information is structured. Objectives To compare and contrast report format and content features of journal-published (JP) and non-journal published (NJP) RRs. Methods JP RRs were identified from key databases, and NJP RRs were identified from a grey literature search of 148 RR producing organizations and were sampled proportionate to cluster size by organization and pro…