Export 55 results:
Sort by: Author Title Type [ Year  (Desc)]
Rebelo, H. B., and C. Cismasiu. "Robustness assessment of a deterministically designed sacrificial cladding for structural protection." Engineering Structures. 240 (2021): 112279. AbstractWebsite

Being able to efficiently mitigate the effects of blast loads on structures, sacrificial cladding solutions are increasingly used to protect structural elements from the effects of accidental explosions and/or terrorist attacks. The present study analyses the loss of effectiveness of a deterministically designed sacrificial cladding when variability in the material properties and uncertainties in the mechanical model are considered. The results of an experimental campaign are used to validate the numerical models that allow the deterministic design of a sacrificial cladding which successfully improves the blast resistant capabilities of a given structural element. Nonetheless, it is shown that, taking into account the probabilistic variability of key parameters is of vital importance when designing sacrificial cladding solutions, since, when not properly designed for the structural element it intends to protect, adding a sacrificial cladding might negatively impact its blast resistant capabilities. Additionally, it is concluded that the deterministic approach might be against safety. In the reported case study, when comparing the admissible charge weight yielding from the deterministic and probabilistic approaches, one verifies that the former allows a higher charge weight.

Cismaşiu, Corneliu, Pedro B. S. Silva, José V. Lemos, and Ildi Cismaşiu. "Seismic Vulnerability Assessment of a Stone Arch Using Discrete Elements." International Journal of Architectural Heritage (2021): 1-15. AbstractWebsite
Santos, F. A., H. Rebelo, M. Coutinho, L. S. Sutherland, C. Cismasiu, I. Farina, and F. Fraternali. "Low velocity impact response of 3D printed structures formed by cellular metamaterials and stiffening plates: PLA vs. PETg." Composite Structures (2020): 113128. AbstractWebsite

This work studies the low-velocity impact response of 3D-printed layered structures made of thermoplastic materials (PLA and PETg), which form sacrificial claddings for impact protection. The analyzed structures are composed of crushable cellular cores placed in between terminal stiffening plates. The cores tessellate either honeycomb hexagonal unit cells, or hexagonal cells with re-entrant corners, with the latter exhibiting auxetic response. The given results highlight that the examined PETg protectors exhibit higher energy dissipation ratios and lower restitution coefficients, as compared to PLA structures that have the same geometry. It is concluded that PETg qualifies as an useful material for the fabrication of effective impact protection gear through ordinary, low-cost 3D printers.

da Silva, Pedro Boto Semblano, Corneliu Cismasiu, and José Vieira de Lemos. "Avaliação da vulnerabilidade sísmica de um arco em alvenaria utilizando o método dos elementos discretos." SÍSMICA 2019 - 11º Congresso Nacional de Sismologia e Enhenharia Sísmica. Lisboa 2019. final_sismica2019.pdf
Rebelo, H. B., D. Lecompte, C. Cismaşiu, A. Jonet, B. Belkassem, and A. Maazoun. "3D printed PLA sacrificial honeycomb cladding blast mitigation." 18th International Symposium for the Interaction of Munitions with Structures (ISIEMS). Panama City Beach, FL, USA 2019.
Rebelo, H. B., D. Lecompte, C. Cismasiu, A. Jonet, B. Belkassem, and A. Maazoun. "Experimental and numerical investigation on 3D printed PLA sacrificial honeycomb cladding." International Journal of Impact Engineering. 131 (2019): 162-173.Website
Rebelo, Hugo Bento, Filipe Amarante dos Santos, Corneliu Cismasiu, and Duarte Santos. "Exploratory study on geodesic domes under blast loads." International Journal of Protective Structures (2019).
Gomes, G., V. Lúcio, C. Cismasiu, and H. Rebelo. "Blast Assessment – A Methodology." ISMS 2018 10th Anniversary Conference: Military Sciences and Future Security Challenges. War Studies University, Warsaw 2018. gomes.pdf
Rebelo, H. B., A. Gregório, P. A. R. Rosa, D. Lecompte, and C. Cismaşiu. "Experimental characterization of 3D-printed PLA under uniaxial high strain-rate loading." AuxDefense 2018 – 1st World Conference on Advanced Materials for Defense. Lisbon 2018. auxdefense_extabstract_v2.pdf
G, Gomes, Lúcio V, Cismasiu C, and Rebelo H. B. "Blast Assessment - uma metodologia de avaliação." Construção Magazine.86 (2018): 18-23.
Amarante dos Santos, Filipe, Corneliu Cismasiu, and Francisco Braz Fernandes. "Cyclic Instability of Shape-Memory Alloys in Seismic Isolation Systems." International Journal of Structural Glass and Advanced Materials Research (2018): 1-14.
Santos, Filipe, Corneliu Cismasiu, Ildi Cismasiu, and Chiara Bedon. "Dynamic Characterisation and Finite Element Updating of a RC Stadium Grandstand." Buildings. 8.10 (2018): 141, 1-19.
Cismasiu, C., J. R. G. Ferreira, and H. B. Rebelo. "Modelação tridimensional de ondas de choque em LS-DYNA." Construção Magazine.86 (2018): 24-28.
Cismaşiu, Corneliu, Filipe Amarante Dos P. Santos, Rui Da Silva A. Perdigão, Vasco M. S. Bernardo, Paulo X. Candeias, Alexandra R. Carvalho, and Luís M. C. Guerreiro. "Seismic Vulnerability Assessment of a RC Pedestrian Crossing." JOURNAL OF EARTHQUAKE ENGINEERING. X.X (2018): 1-19.
Rebelo, Hugo Bento, and Corneliu Cismasiu. "A Comparison between Three Air Blast Simulation Techniques in LS-DYNA." 11th European LS-DYNA Conference 2017. Salzburg, Austria: DYNAMORE, 2017.
Joaquim, Ana, Corneliu Cismasiu, Filipe Santos, and Elsa Caetano. "Estimation of the tensile force in the stay-cables of Salgueiro Maia Bridge using ambient vibration tests." ISDAC2017 - International Symposium on the Dynamics and Aerodynamics of Cables. Porto: FEUP, 2017. artigo_isdac_v5_ec.pdf
Campian, C., M. Pop, C. Cismasiu, T. Josza, and A. Popa. "Seismic retrofitting of an existing steel structure." 17th International Multidisciplinary Scientific GeoConference SGEM 2017. Albena; Bulgaria 2017.
Rebelo, Hugo Miguel Bento, Corneliu Cismasiu, Válter José Guia da Lúcio, Manuel Tomás Marques Souto do Gonçalves, Gabriel Jesus de Gomes, and José Pedro Fernandes Basto. "Numerical Simulation of Blast Effects on Fibre Grout Strengthened RC Panels." International Conference on Structural and Mechanical Engineering for Security and Prevention 2017. Prague, Czech Republic 2017.
Rebelo, Hugo Bento, Corneliu Cismaşiu, Válter J. G. Lúcio, Manuel T. M. S. Gonçalves, Gabriel J. Gomes, and José P. F. Basto. "Numerical Simulation of Blast Effects on Fibre Grout Strengthened RC Panels." Structural and Mechanical Engineering for Security and Prevention. Vol. 755. Key Engineering Materials, 755. Trans Tech Publications, 2017. 18-30. Abstract

The present paper aims to examine the potential of the Applied Element Method (AEM) in simulating the blast effects in RC panels. The numerical estimates are compared with the results obtained in an experimental campaign designed to investigate the effectiveness of fibre grout for strengthening full scale RC panels by comparing the effects that a similar blast load produces in a reference and the strengthened panel. First, a numerical model of the reference specimen was created in the software Extreme Loading for Structures and calibrated to match the experimental results. With no further calibration, the fibre reinforced grout strengthening was added and the resulting numerical model subjected to the same blast load. The experimental blast effects on both reference and strengthened panels, despite the lack of high speed measurement equipment (pressure, strains and displacements sensors), compare well with the numerical estimates in terms of residual and maximum displacements, showing that, once calibrated, the AEM numerical models can be successfully used to simulate blast effects in RC panels.

Cismasiu, C., A. P. Ramos, I. D. Moldovan, D. F. Ferreira, and J. B. Filho. "Applied element method simulation of experimental failure modes in RC shear walls." Computers and Concrete. 19.4 (2017): 365-374.
Rebelo, Hugo, Gabriel Gomes, and Corneliu Cismasiu. "Simulação Numérica do Efeito de Explosivos em Painéis de Betão Armado Reforçados com Argamassas Armadas." BE2016. FCTUC 2016.
Santos, F., C. Cismasiu, R. Perdigão, V. Bernardo, J. Sampayo, P. Candeias, A. Costa, A. Carvalho, and L. Guerreiro COMPORTAMENTO SÍSMICO DE LIGAÇÕES EM PASSADIÇOS PRÉ-FABRICADOS. 10º Congresso Nacional de Sismologia e Engenharia Sísmica. Ponta Delgada, 2016.artigosismica2016_submetido.docx
Amarante dos Santos, Filipe, Corneliu Cismasiu, and Chiara Bedon. "Smart glazed cable facade subjected to a blast loading." Proceedings of the Institution of Civil Engineers - Structures and Buildings. 3.169 (2016): 223-232.
Amarante dos Santos, Filipe, and Corneliu Cismaşiu. "Adaptive underslung beam using shape-memory alloys for frequency-tuning." Journal of Intelligent Material Systems and Structures (2016). AbstractWebsite

The present article addresses the study of an adaptive-passive beam structure with a shape-memory alloy based actuator. In order to mitigate adverse dynamic effects resulting from externally induced vibrations, the structure is able to automatically tune its natural frequency to avoid resonance. The adaptive-passive beam configuration is based on an underslung cable-stayed girder concept. Its frequency tuning is achieved by temperature modulation of the shape-memory alloy elements through a closed-loop control process based on a proportional-integral-derivative algorithm. The effectiveness of the proposed control solution is substantiated by numerical simulations and experimental tests on a small-scale prototype. The validated numerical model enables the simulation of the proposed control approach in a real-scale footbridge, subjected to a prescribed pedestrian loading. The results are very encouraging and show that, by activating the shape-memory alloy elements, the system is able to successfully shift its natural frequency and to mitigate the effects of induced vibrations.

Bedon, Chiara, Filipe Santos, Claudio Amadio, and Corneliu Cismasiu. "Passive and active control systems for adaptive glazing systems and envelopes." European COST Action TU1403 "Adaptive facades network" Industry Workshop. Delft, The Netherlands 2015.