Experimental tests for the seismic response evaluation of cold-formed steel shear walls sheathed with nailed gypsum-based panels

The European project named "Energy Efficient LIghtweight-Sustainable-SAfe-Steel Construction" (Project acronym: ELISSA) is devoted to the development and demonstration of cold-formed steel (CFS) modular systems. In particular, these systems are nano-enhanced prefabricated lightweight steel skeleton/dry wall construction with improved thermal, vibration/seismic and fire performance, resulting from the inherent thermal, damping and fire spread prevention properties. The different building performances are studied and improved by means of experimental and numerical activities organized on three scale levels: micro-scale, meso-scale and macro-scale. In particular, the evaluation of the seismic performance is carried out at the University of Naples by means tests on connections (micro), seismic-resistant systems (meso) and full-scale two stories house prototype (macro). From a structural point of view, the system is a sheathed-braced CFS solution, in which the seismic resistant elements are made of CFS stud shear walls laterally braced by gypsum-based panels. In the adopted solution, the sheathing panels are attached to the CFS frame by means of ballistic nails, whereas clinching points are used for steel-to-steel connections. The present paper illustrates the results of meso-scale tests performed on four full scale shear walls, in which the influence of the aspect ratio, the type of loading and the effect of finishing was investigated

Caratterizzazione sperimentale della risposta sismica di componenti non strutturali basati sull’utilizzo di profili in acciaio formato a freddo

L’attuale interesse del mercato delle costruzioni sembra essere sempre più indirizzato a soluzioni integrate che rispondano ad una molteplicità di requisiti prestazionali, quali buon comportamento fisico/meccanico, facilità e velocità di esecuzione, elevato livello qualitativo e, fattore sempre più importante, economia del ciclo di vita. In quest’ottica, i sistemi realizzati “a secco” mediante l’impiego di profili in acciaio zincato formato a freddo si configurano come soluzioni molto competitive, sia in ambito di applicazioni strutturali, che nel campo delle soluzioni non strutturali. In questo contesto, si inquadra la recente attività di ricerca in corso presso l’Università degli Studi di Napoli “Federico II”, svolta in collaborazione con la multinazionale Knauf Gips KG, sul comportamento sismico di componenti non strutturali che si basano sull’utilizzo di profili in acciaio zincato formato a freddo, quali pareti di partizione e controsoffitti sospesi continui, di cui in questa memoria si presentato i principali aspett

Partizioni lightweight steel rivestite in cartongesso: caratterizzazione sperimentale della risposta sismica fuori piano (Lightweight steel drywall partitions: experimental characterization of the out-of-plane seismic response)

Il danneggiamento sismico di componenti non-strutturali in caso di evento sismico può comportare l’interruzione di funzionalità degli edifici interessati e perdite economiche notevoli. Tra i componenti non-strutturali, i sistemi costituiti da partizioni e controsoffitti rappresentano un investimento significativo nel settore delle costruzioni. Tuttavia, la questione dell’adeguata progettazione sismica di tali sistemi riveste ancora un ruolo di secondaria importanza nell’ambito della progettazione strutturale, riflettendosi in notevoli carenze normative. Poiché il comportamento di tali sistemi non può essere facilmente simulato tramite i tradizionali metodi di analisi, la caratterizzazione sperimentale può rappresentare l’unica procedura efficace. In questo scenario si inquadra la collaborazione tra la KnaufGips KG e l’Università di Napoli “Federico II”, finalizzata alla conoscenza della risposta sismica di sistemi non-strutturali lightweight steel, ossia di partizioni e controsoffitti continui realizzati con profili cold-formed e rivestiti con pannelli in cartongesso. La presente memoria illustra e discute nello specifico le prove monotone quasi-statiche e le prove di identificazione dinamica fuori piano condotte su pareti di partizione, illustrandone i principali risultati ottenuti. (The seismic damage of non-structural components could involve functionality interruption of the most affected buildings and substantial economic losses. Among non-structural components, the ceiling-partitions systems represent a significant investment in the construction sector. Nevertheless, the proper seismic design of these systems plays a secondary role within the structural design, by leading to a lack of specific design provisions. Since the behaviour of these systems cannot be easily simulated with traditional analysis methods, the experimental characterization is an effective procedure. For these reasons, an important collaboration between the KnaufGips KG group and University of Naples “Federico II” commenced over the last few years. The main objective of the research is to investigate the seismic performance of non-structural lightweight steel drywall systems, i.e. partitions and suspended continuous ceilings made of cold-formed steel profiles sheathed with gypsum-based panels. The presented paper describes and discusses particularly the out-ofplane quasi-static monotonic tests and dynamic identification tests carried out on partition walls.

Seismic behaviour of non structural systems in CFS: characterization of seismic response through shake-table tests

The seismic damage of non-structural components could involve functionality interruption of the most affected buildings and substantial economic losses. Therefore, a cooperation be-tween the University of Naples "Federico II" and KnaufGips KG Company, aimed to the knowledge of seismic response of lightweight steel drywall nonstructural components was car-ried forward. The paper presents the dynamic tests on shaking table of protoypes composed by interior partition walls, exterior façade walls and suspended continuous ceilings. The influ-ence on seismic response of basic and enhanced anti-seismic solutions, corresponding to the use of fixed or sliding connections at the walls and ceilings perimeter, was investigated. The seismic response in terms of damage occurrence was also evaluated by fragility curves, which show that enhanced solutions have a better seismic response than basic solutions and interior partition walls have a higher seismic “fragility” than exterior façade walls

Atypical pleomorphic xanthoastrocytoma

A 65-year-old man experienced an ictal episode. CT revealed a left capsulo-thalamic mass, and SPET showed hypoperfusion of the left cerebral emisphere. The lesion was subtotally removed, and postoperative radiotherapy was given. Pathological examination demonstrated an "atypical" pleomorphic xanthoastrocytoma. The patient died of massive regrowth of the tumor 22 months after surgery. This case is discussed in light of the pertinent literature

Encapsulated intracerebral hematoma: a case report and review of the literature.

A case of encapsulated intracerebral hematoma is described in the light of the relevant literature. The etiopathogenesis, diagnostic problems and treatment of this rare entity are also discussed