Creep behaviour of cracked steel fibre reinforced self-compacting concrete laminar structures

Tese de Doutoramento - Civil Engineering

High strain rate constitutive modeling forhistorical structures subjected to blast loading

Doctoral Thesis Civil Engineering

A sixth-order finite volume method for the 1D biharmonic operator: application to intramedullary nail simulation

A new very high-order finite volume method to solve problems with harmonic and biharmonic operators for one- dimensional geometries is proposed. The main ingredient is polynomial reconstruction based on local interpolations of mean values providing accurate approximations of the solution up to the sixth-order accuracy. First developed with the harmonic operator, an extension for the biharmonic operator is obtained, which allows designing a very high-order finite volume scheme where the solution is obtained by solving a matrix-free problem. An application in elasticity coupling the two operators is presented. We consider a beam subject to a combination of tensile and bending loads, where the main goal is the stress critical point determination for an intramedullary nail.

Assessment of the properties to characterize the interface between clay brick substrate and strengthening mortar

The behaviour of masonry elements under in-plane and out-of-plane loads can be improved through the application of strengthening systems based on reinforcing overlays. After strengthening, the transition region between the original substrate and the strengthening layer is especially stressed, and premature failure of the strengthened masonry is reached if insufficient interfacial capacity is assured. Therefore, the assessment of the mechanical behaviour of the interface is critical to the development of the masonry strengthening system based on the application of strengthening overlays. In this research a method for the characterization of the interface behaviour between two different materials, a polypropylene fibre reinforced mortar (PFRM) and a ceramic brick used for masonry construction is presented. Direct shear tests were carried out in couplet specimens. Due to the orthotropic nature of the bricks surface, the shear load was applied along three different directions in order to perform an overall estimation of the interface behaviour. The peak and residual shear stresses, as well as the failure modes, were obtained at different levels of the normal stress. Based on these experimental results constitutive laws were assessed for the simulation of the interface mechanical behaviour based on the Mohr and Mohr-Coulomb failure criteria.

One-step in situ synthesis of polyamide microcapsules with inorganic payload and their transformation into responsive thermoplastic composite materials

Well-dispersed loads of finely powdered metals, metal oxides, several carbon allotropes or nanoclays are incorporated into highly porous polyamide 6 microcapsules in controllable amounts via an original one-step in situ fabrication technique. It is based on activated anionic polymerization (AAP) of ε-caprolactam in a hydrocarbon solvent performed in the presence of the respective micro- or nanosized loads. The forming microcapsules with typical diameters of 25-50 µm entrap up to 40 wt% of load. Their melt processing produces hybrid thermoplastic composites. Mechanical, electric conductivity and magnetic response measurements show that transforming of in situ loaded microcapsules into composites by melt processing (MP) is a facile and rapid method to fabricate materials with high mechanical resistance and electro-magnetic characteristics sufficient for many industrial applications. This novel concept requires low polymerization temperatures, no functionalization or compatibilization of the loads and it is easy to scale up at industrial production levels.

Seismic retrofit of masonry-to-timber connections in historical constructions

Tese de Doutoramento em Engenharia Civil.

O Conceito de Autarquias Locais na Constituição da República de Angola: o caso do Município

Dissertação de mestrado em Direito Administrativo

Development of high specific strength components, with internal cellular structure, for several applications

Dissertação de mestrado em Engenharia Mecânica

Wear of PEEK-Ti6Al4V systems under micro-abrasion and linear sliding conditions

Dissertação de mestrado integrado em Engenharia Biomédica

Estudo do comportamento tribológico de materiais compósitos à base de titânio reforçado com partículas cerâmicas para aplicação em implantes articulares

Dissertação de mestrado integrado em Engenharia Biomédica

Projecto de componentes estruturais recorrendo a soluções avançadas em aços de alta resistência

Dissertação de mestrado integrado em Engenharia Mecânica

Desenvolvimento de modelos numéricos e análise experimental de subestruturas soldadas de transformadores de potência, sujeitas a forças de curto-circuito em regime transitório

Dissertação de mestrado integrado em Engenharia Mecânica

Development of procedures for the design, optimization and manufacturing of customized orthopaedic and trauma implants: Geometrical/anatomical modelling from 3D medical imaging

Tese de Doutoramento (Programa Doutoral em Engenharia Biomédica)

Estudo da cabeceira da Sé do Porto

Dissertação de mestrado integrado em Engenharia Civil

Modelação numérica de uma solução de reforço de solos para fundações de aerogeradores

Dissertação de mestrado integrado em Engenharia Civil