Jaime Monteiro

Simoldes Plásticos · R&D

A method for the evaluation of noise in measurements with shearography is reported in this paper. This method is able to quantify the influence of several parameters, namely the shearing amount and the vibration amplitude of rotations, on the measurements accuracy. The method was applied to the first four modal rotation fields of an aluminum beam i...

The objective of this work is the application of an interferometric method for validating the result of wear in a cutting tool insert of hard metal. We describe in this paper the experimental setup for the application of Digital Holography technique, used with digital recording of holograms on a CCD camera. The cutting insert inspected with the opt...

The use of implants to rehabilitation of total edentulous, partial edentulous or single tooth is increasing, it is due to the high rate of success that this type of treatment present. The objective of this study was to analyze the mechanical behavior of different positions of two dental implants in a rehabilitation of 4 teeth in the region of maxil...

Structural components may contain cracks, and for these components a crack tip represents a highly singular stress. The evaluation of the associated strain gradient is difficult to achieve with experimental discrete methods. An efficient alternative are the optical techniques which are non-contact, and so delivering continuous information of the di...

Photo-activated composites started to be used from the 60´s, and are nowadays widely applied for dental restorative procedures. In that respect they have almost replaced amalgam fillings. Composites are directly bonded into teeth hard tissues restoring most of the original strength structure. This study concerns to experimental hybrid composites de...

  A mixed formulation in the characterization of internal forces and displacements in cylindrical shells, subjected to radial forces is presented. This numerical approach is proposed as an alternative to the irreducible formulation, where in some problems this solution leads to stress distribution presenting some discontinuity along the edge joinin...

The fundamental objective of this work consists of the application of optical interferometric methods for validation of the result of friction in hard metal pastil. Descreve-neste work to experimental montagem, for application of the technique of Digital Holography, used for the recording of digital holograms in CCD. The pastil that was inspected w...

  The main goal of this work was the development of experimental techniques to measure in depth non-uniform residual stresses, as alternative to the more conventional hole-drilling method with strain gauges. The proposed experimental methodology is based on moiré interferometry. This high resolution field technique allows in-plane displacement asse...

The purpose of this article is to study the application of the holographic interferometry techniques in the structural analysis of submarine environment. These techniques are widely used today, with applications in many areas. Nevertheless, its application in submarine environments presents some challenges. The application of two techniques, electr...

  The goal of this work was the development of other experimental techniques to measure residual stresses, as an alternative to the hole-drilling method with strain gauges. The proposed experimental techniques are based on the use of Moiré interferometry and in-plane electronic speckle pattern interferometry (ESPI). Both are field techniques allowi...

Um sistema baseado na interferência de dois feixes de luz monocromática, como é o interferómetro de Michelson, é usado normalmente como padrão, para a medição de deslocamento, nos laboratórios de metrologia. Sendo um equipamento sofisticado, pouco usual num laboratório de ensino e de investigação, e considerando o interesse do seu conhecimento em d...

In this work the actuator performance of a ceramic piezoelectric device is studied. Its ability of deforming a Carbon Fiber Reinforced Plastic (CFRP) laminate is measured in the absence/presence of mechanical constraints. Deformation and bending of the CFRP laminate is obtained when a voltage is applied to the piezoelectric device. This deformation...

When using conventional surface strain measurement techniques (e.g. strain gauges, dial gauges), the measurement of deformations within cancellous bone is frequently hampered by the material's highly porous structure and poor mechanical properties. Although detailed strain maps derived from actual experimental data have the potential to resolve man...

Reinforced thermoplastic and thermosetting matrix pipes, produced by filament winding or centrifugal casting, may be subjected to different types of loading conditions as well as different environmental conditions. However, they may suffer damage due to unexpected working conditions (low velocity impact, such as stones, tools, etc). This paper desc...

Reinforced thermoplastic matrix pipes may be subjected to different types of loading conditions as well as different environmental conditions. However, they may suffer damage due to unexpected working conditions (low velocity impact, such as stones, tools, etc). This paper describes a methodology based upon fracture mechanics to evaluate possible p...

Pretende-se com este trabalho estudar a aplicação das técnicas de interferometria holográfica à análise estrutural em ambiente subaquático. Estas técnicas estão hoje bem divulgadas e com aplicações em diversas áreas. No entanto, a sua aplicação em ambientes subaquáticos, apresenta alguns desafios. Neste trabalho estuda-se a aplicação de duas técnic...

An optical set-up based on the combination of new CCD technology, a ruby laser and a Mach-Zehnder shear interferometer is presented for defect detection in composites. Transient loads are used to excite defects in a sandwich structure and image-processing routines allow improving the detection resolution. Phase calculation is obtained by FFT algori...

The problem of shape control and correction of small displacements in composite structures using piezoelectric actuators glued or embedded was addressed. A finite element model based on Mindlin plate theory was used to characterize the behaviour of the structure and the one of the actuators. Emphasis was put on the development of an efficient and g...

The aim of this paper is to describe a new numerical-experimental method to determine the stiffness of a conceptual proximal femoral prototype. The methodology consists of the comparison of the numerical and experimental displacement distributions of the prosthesis loaded as a cantilever beam to validate a design concept: controlled stiffness prost...

An experimental procedure based on holographic interferometry coupled with computer-aided image processing techniques was used to estimate the stress intensity factor (SIF) of a part-through crack in a plate. The loading consisted of a uniform remote tensile stress, leading to an opening and edge rotation displacement field along the crack plane. T...

This paper describes a new application of two laser interferometry techniques to the non-destructive inspection (NDI) of coated surfaces. The purpose is to detect interfacial disbond between the coating and the substrate. Debonding is detected by properly exciting the surface of the object under inspection in such a way that the interference fringe...

This paper presents some results of an inspection program to detect coating-substract defects using a Michelson type of shear interferometer. Debonding defects are detected by properly loading the surface of the specimen in such a way that the interference fringe pattern is modified, rendering the debond readily visible. Image processing techniques...

This paper presents some results of an inspection program to detect coating-substract defects using a Michelson type of shear interferometer. Debonding defects are detected by properly loading the surface of the specimen in such a way that the interference fringe pattern is modified, rendering the debond readily visible. Image processing techniques...

The application of laser interferometry techniques to study the dynamic behaviour of structural components is described. Being a non contact field technique, it allows the measurement of a dynamic displacement fields without need of additional fitting of transducers, which would change the mass of the structure. Image processing techniques are alre...

Recibido 5 de abril de 2004, revisado 9 de noviembre de 2004, para publicación 25 de febrero de 2005) Resumo – No presente trabalho utilizam-se as técnicas de interferometria holográfica para a detecção de defei-tos em placas laminadas de carbono/epóxido. Foram analisadas placas com 16 camadas e duas orientações de fibras, sendo uma simétrica, [0,9...

Resumo. Para medição de tensões residuais instaladas em componentes ou estruturas, é normalmente utilizado o método do furo. Trata-se de um método experimental que pode ser simulado numericamente, através das funções "KILL and BIRTH". Neste trabalho serão apresentados três simulações de aplicação à mecânica experimental. Na primeira aplicação é efe...

RESUMO Este trabalho tem como objectivo principal o estudo experimental/numérico da propagação de ondas de flexão em estruturas laminadas tipo placa. A medição do campo de deslocamentos é efectuada por holografia TV de duplo impulso. Para o efeito foi desenvolvida uma montagem experimental utilizando um LASER de Rubi e um sistema de controlo para,...

Tese de mestrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 1999