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Finite element analysis of stent expansion: influence of stent geometry on perf...
Gomes, Inês Varela; Puga, Hélder; Alves, J. L.; Claro, José Carlos PimentaIschaemic heart diseases are a global health problem that have been increasing in the recent years [1]. Most of ischaemic heart diseases is caused by atherosclerosis, a clinical pathology characterized by the deposition of fatty material on the arteries walls what may lead to thickening, hardening and blocking of these blood vessels, reducing the blood flow. This situation can cause heart attack, stroke and, in...
Desenvolvimento de um modelo multicorpo de um sistema metálico de retenção rodo...
Carvalho, J. M. Simões; Claro, José Carlos PimentaEste trabalho tem como objetivo a criação e validação de um modelo virtual multicorpo (MBS), capaz de simular o comportamento de sistemas metálicos de retenção rodoviária - vulgarmente denominados por “rails” - numa ótica de rápida, económica e eficaz pré-avaliação do desempenho geral do conjunto em trabalho e dos seus componentes individuais, tendo como fim último a criação de uma ferramenta de auxílio ao dese...
A survey and comparison of several friction force models for dynamic analysis o...
Marques, Pedro Filipe Lima; Flores, Paulo; Claro, José Carlos Pimenta; Lankarani, Hamid M.This study is aimed at examining and comparing several friction force models dealing with different friction phenomena in the context of multibody system dynamics. For this purpose, a comprehensive review of present literature in this field of investigation is first presented. In this process, the main aspects related to friction are discussed, with particular emphasis on the pure dry sliding friction, stick–sl...
Criação dos discos intervertebrais da coluna lombar utilizando o software MSC v...
Sousa, Amélia Sofia Moreira Neto Mendes de; Claro, José Carlos PimentaUm modelo da coluna lombar humana foi construído em sistema multicorpo (MBS), utilizando o software comercial MSC visualNastran Desktop®. Sendo a entidade mais utilizada para a simulação dos discos intervertebrais (IVD) o denominado “bushing”, no entanto, e devido a algumas peculiaridades apresentadas pelo software, o uso desse tipo de junta tornouse inviável, tendo sido necessário criar os discos intervertebra...
Modelação esquelética humana simplificada, multicorpo, para análise de solicita...
Sousa, Vanessa Cunha de; Claro, José Carlos PimentaA avaliação das cargas na coluna vertebral é extremamente importante, uma vez que está intimamente relacionada com a biomecânica da coluna e suas patologias. Neste estudo, é apresentado um modelo multicorpo tridimensional simplificado da estrutura esquelética humana, para o estudo das forças e binários a que a zona lombar da coluna vertebral está sujeita durante a flexão frontal e flexão lateral. Para validação...
The intradiscal failure pressure on porcine lumbar intervertebral discs: an exp...
Araújo, Ângelo Rafael Gomes; Peixinho, Nuno; Pinho, A. C. Marques; Claro, José Carlos PimentaThe intervertebral disc is submitted to complex loading during its normal daily activities which are responsible for variations of the hydrostatic pressure in its structure. Thus, the determination of the magnitude of failure hydrostatic pressure is essential as a potential for the evaluation of the mechanisms that promote the weakening and the disruption of the annular fibers, commonly linked to herniation pro...
Biomechanical experimental data curation: an example for main lumbar spine liga...
Lourenço, Carina Patrícia Araújo; Claro, José Carlos PimentaThis work overviews an extensive analysis in the context of mechanical characterization of human biomaterials, carried out over a broad set of published experimental data. Focused on main lumbar spine ligaments, several test procedures are exhaustively analyzed, in order to identify possible causes for divergences that have been found in some results. Moreover, guidelines are proposed for da-ta filtering and se...
Comparison between the dynamic and initial creep response of porcine and human ...
Araújo, Ângelo Rafael Gomes; Peixinho, Nuno; Pinho, A. C. Marques; Claro, José Carlos PimentaThe study of mechanical properties of intervertebral disc (IVD) is important for the evaluation of disc implants. To determine these properties, several animal spine models were used. The goal of this work is to determine and compare the dynamic stiffness coefficient (K-d) and initial creep behavior of porcine intervertebral disc with the human ones. Porcine lumbar "motion segments" were subjected to 1200 cycle...
On the experimental intradiscal pressure measurement techniques : a review
Araújo, Ângelo Rafael Gomes; Peixinho, Nuno; Pinho, A. C. Marques de; Claro, José Carlos PimentaThe intradiscal pressure has been essential for prevent the spinal complaints by forming a basis for clinical advice to promote the correct sitting postures. As a consequence, it is evident the need of an accurate method for measure the intradiscal pressure, to better understand the disc response to hydorstatic pressure fluctuations. Numerous reviews regarding disc mechanics are available, including intradiscal...
Quasi-static and dynamic properties of the intervertebral disc: experimental st...
Araújo, Ângelo Rafael Gomes; Peixinho, Nuno; Pinho, A. C. Marques; Claro, José Carlos PimentaPurpose: The study of axial loading is essential to determine the properties of intervertebral disc. The objectives of this work are (1) to quantify the mechanical properties of porcine lumbar intervertebral discs under static and cyclic compressive loading, and (2) to determine the parameters of a five-parameter rheological model for porcine and compare them with those obtained for human lumbar intervertebral ...