Search results for "COSTRUZIONE"
showing 10 items of 669 documents
Impact Force Identification and Location on Isotropic and Composite Panels.
2009
Numerical and Experimental Analysis of the Frictional Effects on 4ENF Delamination Tests Performed on Unidirectional CFRP
2015
Abstract Progressive delamination in composite materials under static or fatigue loading condition are, in many structures, one of the predominant cause of failure. In the paper, an accurate study of quasi-static delamination growth under mode II loading condition is conducted. Several experimental tests are performed on composite laminates consisting of unidirectional carbon/epoxy layers. Four-point end-notched flexure (4ENF) test is employed in order to characterize the mode II interlaminar fracture toughness. The R-curve is obtained by means of optical and numerical determination of crack tip position. The energy release rate and the crack length are calculated through experimental deter…
The effect of through-thickness compressive stress on mode II interlaminar fracture toughness
2017
Abstract The effect of through-thickness compressive stress on mode II interlaminar fracture toughness is investigated experimentally and replicated numerically. The modified Transverse Crack Tensile specimen recently proposed by the authors is used, together with an experimental device designed to apply a constant transverse compressive stress on the surface of the specimen. Experiments are conducted using IM7/8552 specimens for different compressive stresses, ranging from 0 to 100 MPa, covering all the practical applications commonly encountered in the aeronautical industry (e.g., tightened filled holes or bolted joints). It is shown that mode II interlaminar fracture toughness increases …
Regional variation of wall shear stress in ascending thoracic aortic aneurysms.
2014
The development of an ascending thoracic aortic aneurysm is likely caused by excessive hemodynamic loads exerted on the aneurysmal wall. Computational fluid-dynamic analyses were performed on patient-specific ascending thoracic aortic aneurysms obtained from patients with either bicuspid aortic valve or tricuspid aortic valve to evaluate hemodynamic and wall shear parameters, imparting aneurysm enlargement. Results showed an accelerated flow along the outer aortic wall with helical flow in the aneurysm center for bicuspid aortic valve ascending thoracic aortic aneurysms. In a different way, tricuspid aortic valve ascending thoracic aortic aneurysms exhibited normal systolic flow without su…
A preliminary investigation of the effect of contact pressure on the accuracy of heart rate monitoring by wearable PPG wrist band
2019
The increase of safety and health monitor of workers has become a crucial objective to prevent excessive physical workloads, injuries, accidents and errors. Heart rate (HR) is a very important physiological indicator which could properly describe the workers’ physical status. Recently, wearable photoplethysmographic (PPG) wristband trackers have been utilized to measure HR without hindering normal gesture of workers. However, the quality of PPG signals is highly affected by human physical motions, resulting in a poor reliable HR estimation. Specifically, during different activities and gestures, PPG sensor contact pressures may have an impact on the quality of the heart rate signal. To appr…
Caratterizzazione chimica ed isotopica della carota MSK-C4 (Tirreno Meridionale)
2013
Trasferimenti tecnologici nella Sicilia d’età moderna: l'impiego del mattone a “cortina”
2016
In Sicilia, nel contesto di quella che è stata definita la civiltà della pietra, e tra i laboratori della stereotomia medioevale nel Mediterraneo, il ricorso al laterizio e alla tecnica costruttiva che l’impiego di un materiale “artificiale” comporta, ha generato in età moderna fabbriche che hanno operato uno scarto rispetto alla tradizione fino a produrre una nuova tradizione. La serie di casi che sono segnalati in questo contributo indicano come sia stata spesso la mobilità di alcuni maestri “forestieri” a spiegare l’introduzione, l’attecchimento e la fortuna dell’impiego del mattone a faccia vista, o altrimenti detto a “cortina”, nel cantiere siciliano d’età moderna. In Sicily, as a part…
Le consulte collettive nell'architettura siciliana tra tra XVI e XVII secolo
2015
Il contributo esamina alcuni casi di " consulte" di natura costruttiva avvenute nell'architettura siciliana tra XVI e XVII secolo, attraverso la documentazione ad oggi nota. Quello che emerge dal confronto di una serie di documenti è la continuità di certe formule, come nella stima dei costi, mentre le differenze sono evidenti nelle consulenze svolte. Ci sono ad esempio cantieri (come per esempio quello relativo alla chiesa madre di Piazza) dove il processo è frequente mentre ce ne sono altri dove le consulte appaiono discontinue nel tempo (per esempio nella cattedrale di Agrigento). Durante il XVII sussiste anche un divario tra perizie affidate ad architetti e quelle compilate da maestri c…