Out-of-plane behavior of masonry infill walls

In order to investigate the out-of-plane behaviour of masonry infill walls, quasi-static testing was performed on a masonry infill walls built inside a reinforced concrete frame by means of an airbag system to apply the uniform out-of-plane load to each component of the infill. The main advantage of this testing setup is that the out-of-plane loading can be applied more uniformly in the walls, contrarily to point load configuration. The test was performed under displacement control by selecting the mid-point of the infill as control point. Input and output air in the airbag was controlled by using a software to apply a specific displacement in the control point of the infill wall. The effect of the distance between the reaction frame of the airbag and the masonry infill on the effective contact area was previously analysed. Four load cells were attached to the reaction frame to measure the out-of-plane force. The effective contact area of the airbag was calculated by dividing the load measured in load cells by the pressure inside the airbag. When the distance between the reaction walls and the masonry infill wall is smaller, the effective area is closer to the nominal area of the airbag. Deformation and crack patterns of the infill confirm the formation of arching mechanism and two-way bending of the masonry infill. Until collapse of the horizontal interface between infill and upper beam in RC frame, the infill bends in two directions but the failure of that interface which is known as weakest interface due to difficulties in filling the mortar between bricks of last row and upper beam results in the crack opening trough a well-defined path and the consequent collapse of the infill.

Organização e gestão da manutencão de ferramentas numa empresa de produção de peças metálicas

Dissertação de mestrado Engenharia e Gestão da Qualidade

Estudo e caracterização mecânica por via experimental de modelos de subestruturas eletromecânicas aplicadas ao fabrico de transformadores de grande potência

Dissertação de mestrado integrado em Engenharia Mecânica

Avaliação experimental da utilização de conectores indentados em elementos mistos de aço e betão leve

Dissertação de mestrado integrado em Engenharia Civil

Using mouse dynamics to assess stress during online exams

"Lecture notes in computer science series", ISSN 0302-9743, vol. 9121

Depressed mothers and infants are more relaxed during breastfeeding versus bottlefeeding interactions: brief report

Depressed and non-depressed mothers and their 3-month-old infants were videotaped during breastfeeding and bottlefeeding interactions. The videotapes were subsequently coded for a number of feeding interaction behaviors as well as being rated on the Interaction Rating Scales. No differences were noted between the depressed and non-depressed mothers. Several breastfeeding versus bottlefeeding group effects were observed. The breastfeeding mothers showed less burping and less intrusive behavior during the nipple-in periods as well as during the nipple-out periods. In addition, the breastfeeding mothers and their infants received better ratings on the Interaction Rating Scales. These data suggest that the depressed mothers and their infants not unlike the non-depressed mothers and their infants were benefited by breastfeeding.

Modelo de gestão integrada dos contratos públicos eletrónicos orientados ao valor público

Tese de Doutoramento em Tecnologias e Sistemas de Informação.

Numerical Assessment of the out-of-plane response of a brick masonry structure without box behaviour

This paper presents the assessment of the out-of-plane response due to seismic loading of a masonry structure without rigid diaphragm. This structure corresponds to real scale brick masonry specimen with a main façade connected to two return walls. Two modelling approaches were defined for this evaluation. The first one consisted on macro modelling, whereas the second one on simplified micro modelling. As a first step of this study, static nonlinear analyses were conducted to the macro model aiming at evaluating the out-of-plane response and failure mechanism of the masonry structure. A sensibility analyses was performed in order to assess the mesh size and material model dependency. In addition, the macro models were subjected to dynamic nonlinear analyses with time integration in order to assess the collapse mechanism. Finally, these analyses were also applied to a simplified micro model of the masonry structure. Furthermore, these results were compared to experimental response from shaking table tests. It was observed that these numerical techniques simulate correctly the in-plane behaviour of masonry structures. However, the