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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.
Freitas, J. A. T., and C. Cismaşiu. "Adaptive p-refinement of hybrid-{T}refftz finite element solutions." Finite Elements in Analysis and Design. 39 (2003): 1095-1121. Abstract

An adaptive p-refinement procedure for the implementation of the displacement model of the hybrid-{T}refftz finite element formulation is presented. The procedure is designed to select and implement automatically the degrees of freedom in the domain (displacements) and on the boundary (surface forces) of the element to attain a prescribed level of accuracy. This accuracy is measured on the strain energy of the system for a prescribed finite element mesh. Local measures of error can be easily accounted for. The performance of the adaptive procedure suggested is illustrated using two-dimensional potential problems.

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.

Rebelo, Hugo, and Corneliu Cismasiu. "Análise Comparativa entre Modelos Constitutivos para a Simulação de Elementos Estruturais de Betão Armado sujeitos a Cargas de Explosão." PROTEDES2022. Região Sul da Ordem dos Engenheiros, Lisboa 2022.
Oliveira, Tiago, Pedro Matias, and Corneliu Cismasiu. "Análise Experimental e Numérica de Painéis de Vidro Laminado Sujeitos à Ação de Explosões." 4.o ENCONTRO DE I&D EM CIÊNCIAS MILITARES – ECM 2022. Sintra: Academia da Força Aérea, 2022.
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.
Silva, Pedro, José Nuno Varandas, and Corneliu Cismasiu. "AVALIAÇÃO DA VULNERABILIDADE SÍSMICA DE UM PASSADIÇO PEDONAL PARTINDO DA SUA IDENTIFICAÇÃO MODAL DINÂMICA." TEST&E 2022 3rd Conference on Testing and Experimentation in Civil Engineering Smart Technologies. Campus da Caparica, Portugal 2022. 046.pdf
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
Fonseca, Amândio, Corneliu Cismasiu, and Ildi Cismasiu. "Avaliação da vulnerabilidade sísmica de um edifício pombalino através de análise dinâmica incremental." Jornadas Portuguesas de Engenharia de Estruturas (JPEE). Lisboa: LNEC, APEE, GPBE, SPES, 2022. art_jpee2022_266_afccic_v8.pdf
Silva, M. A. G., C. Cismaşiu, and C. G. Chiorean. "Ballistic Simulation of Impact on Composite Laminates." Proceedings of the International Conference Constructions 2003. Vol. 2. Cluj-Napoca, Romania: The Technical University of Cluj-Napoca, 2003. 139-146. Abstract

The paper reports on numerical simulation of impact problems on fiber reinforced plastic composite laminated plates reinforced with Kevlar 29. The ballistic impact caused by STANAG-2920 projectile is analyzed to obtain an estimate for the V50 and the global damage. All estimate have been carried out using the finite difference numerical code AUTODYN-3D, are compared with the experimental data to illustrate the performance of the simulation. Good correlation between resulting simulations and experimental results is demonstrated both in terms of deformation and damage of the laminates and ballistic performance.

G, Gomes, Lúcio V, Cismasiu C, and Rebelo H. B. "Blast Assessment - uma metodologia de avaliação." Construção Magazine.86 (2018): 18-23.
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
dos Santos, Amarante F. P., and C. Cismasiu. "Bridge hinge-restrainers built up of NiTi superelastic shape-memory alloys." Smart Structures and Materials (SMART'11). 5th ECCOMAS Thematic Conference on Smart Structures and Materials SMART'11. Saarbrücken, Germany 2011. Abstractsantos_2011.pdf


dos Santos, Amarante F. P., and C. Cismasiu. "Bridge Hinge-Restrainers Built up of NITI Superelastic Shape-Memory Alloys." New Trends in Smart Technologies . Eds. Christian Boller, and Hartmut Janocha. Saarbrücken: Fraunhofer Verlag, 2013. 195-203.
Freitas, J. A. T., C. Cismasiu, and Z. M. Wang. "Comparative analysis of hybrid-Trefftz stress and displacement elements." Archives of Computational Methods in Engineering. State of the art reviews. 6.1 (1999): 35-39.
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.
dos Santos, Amarante F. P., and C. Cismasiu. "Comparison Between Two SMA Constitutive Models for Seismic Applications." Journal of Vibration and Control. 16 (2010): 897-914. AbstractWebsite

This paper analyses and compares the dynamic behavior of superelastic shape memory alloy (SMA) systems based on two different constitutive models. The first model, although being able to describe the response of the material to complex uniaxial loading histories, is temperature and rate independent. Thesecond model couples the mechanical and kinetic laws of the material with a balance equation considering the thermal effects. After numerical validation and calibration, the behavior of these two models is tested in single degree of freedom dynamic systems, with SMAs acting as restoring elements. Different dynamic loads are considered, including artificially generated seismic actions, in a numerical model of a railway viaduct. Finally, it is shown that, in spite of its simplicity, the temperature- and rate-independent modelproduces a set of very satisfying results. This, together with its robustness and straightforward computational implementation, yields a very appealing numerical tool to simulate superelastic passive control applications.

dos Santos, Amarante F. P., and C. Cismasiu. "Comparison Between Two {SMA} Constitutive Models for Seismic Applications." Twelfth Conference on Nonlinear Vibrations, Dynamics, and Multibody Systems. Blacksburg, VA 24061 2008. Abstract
Oliveira, Tiago, Pedro Matias, and Corneliu Cismasiu. "Comportamento de painéis de vidro laminado à ação de explosões - Geração de curvas Pressão-Impulso." PROTEDES2022. Região Sul da Ordem dos Engenheiros, Lisboa 2022.
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 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.
Gomes, G. J., V. J. G. Lúcio, and C. Cismasiu. "Development of a high-performance blast energy-absorbing system for building structures." AuxDefense2022 - 3rd World Conference on Advanced Materials for Defense. Guimarães, Portugal 2022.
de Gomes, Gabriel Jesus, Valter José Guia da Lúcio, and Corneliu Cismasiu. "Development of a high-performance blast energy-absorbing system for building structures." International Journal of Protective Structures (Submitted): 20414196231183006. AbstractWebsite

Shock absorbers have been widely used in the automotive and aeronautical industries for many years. Inspired on these devices, the paper presents an analytical and numerical assessment of a high performance protective system for building structures against blast loads, which is composed of a shielding element connected to the main structure, at the floor levels, through ductile Energy Absorbing Connectors (EACs). The EACs exploit the external tube inversion mechanism to absorb a significant part of the imparted kinetic energy from the blast wave. While the system prototype has been developed in laboratory, it was characterized and tested in a full-scale blast testing campaign. A validated finite element model was used next to analyze its performance in a more demanding design scenario. The introduction of EACs notably reduces the peak horizontal loads and the kinetic energy transferred to the protected structure, being expected a significant reduction of the stresses in the supporting vertical elements, in addition to the protection of structural and non-structural members. These results encourage further studies of the presented protective system that can be potentially employed for a large variety of blast threat scenarios, especially when increasing the stand-off is not a possible/viable option and sensitive facilities have to be protected.

Freitas, J. A. T., and C. Cismaşiu. "Developments with hybrid-{T}refftz stress and displacement elements." Computer Assisted Mechanics and Engineering Sciences. 8 (2001): 289-311. Abstract

The paper reports on the work on hybrid-{T}refftz finite elements developed by the Structural Analysis Research Group, ICIST, Technical University of Lisbon. A dynamic elastoplastic problem is used to describe the technique used to establish the alternative stress and displacement models of the hybrid-{T}refftz finite element formulations. They are derived using independent time, space and finite element bases, so that the resulting solving systems are symmetric, sparse, naturally $p$-adaptive and particularly well suited to parallel processing. The performance of the hybrid-{T}refftz stress and displacement models is illustrated with a number of representative static and dynamic applications of elastic and elastoplastic structural problems.