Matosinhos Market (1936)

Drawing of the market

Matosinhos Market: an early example of a concrete thin-shell. Author: ARS arquitectos.

The roof is a barrel vault with reinforcement ribs on the outside. The cross section is a parabola. It spans 38 meters, with 11 m of height and a shell width of only 7 cm.

The project was born in 1936, when the Local Council held an architectural competition to design a new Market building. ARS Arquitectos, a Porto-based architects team (Cunha Leão, Morais Soares e Fortunato Cabral), won the competition. In 1939, the architects presented the final project, after changing the original design.

The building works began in 1944 (the delay was due to problems with expropriations), and lasted until 1952, when the Market was opened. Economic difficulties arising from the World War made great impact in this project, due to shortage of materials (steel, concrete).

The construction of the paraboloidal arches was made with wooden formworks over wheels.

Aerial view (Bing Maps)

LINKS

• Câmara assinala 60 anos do Mercado de Matosinhos
• Leça-da-palmeira-antropologica-VIII 
• Leça-da-palmeira-antropologica-IX 
• Patrimonio Cultural 
• docomomoiberico 

Analysis of a Beam with Salome-Meca and Code_Aster

Salome-Meca is not intended for the analysis of simple beams, but of more complicated structures. However, as I begin to learn this application, I feel more comfortable with simple cases. In this entry, the analysis process of a simple beam with Salome-Meca is shown. In spite of its simplicity, one must know how to do some tricks, specially how to use Groups.

In this exercise, the beam analyzed has two supports: a pinned one at the end A, and a roller at B. Its cross section = 0,20x0,30 sq. meters. A vertical load of 30 kN is applied at the free end C.

The COMM file was created using an application called Efficient. For me, dealing with those COMM files was a tough task. Efficient makes things easier. Great stuff. You can find it at the Moonish Engineering site.

Links to the videos:

• Part 1
• Part 2
• Part 3

Desplacement at C. Analytical solution: 0,002539 meters. Salome-Meca: 0,002561 meters. Difference: 0,8%.

How to model a beam with variable cross section in Ansys

A beam with variable cross section can be easily modeled with FEM software using Solid or Shell elements. In this little tutorial, however, the beam was meshed using BEAM elements. These were chosen for future plans of combinating them with SHELL elements.

When BEAM elements are used, geometry variation is modeled with the Tapered Section option.

Link to video

Salome-Meca: creating and meshing a surface of revolution

First Tutorial: how to create a surface of revolution in Salome-Meca (Finite Element software).

1) Create four points. 2) Create two lines. 3) Generate surface of revolution with line 1 and line 2.

Second Tutorial: how to mesh a surface of revolution in Salome-Meca.

1) Go to meshing module. 2) Create the mesh, selecting the surface. 3) Compute the mesh.

This is not a good mesh, just an example of how to do it quickly.

Salome-Meca: iniciar la aplicación

Una vez tengamos instalada la aplicación Salome-Meca, veamos cómo se inicia. Explicaré cómo se hace en Linux.

1. Abrir una ventana de terminal.

2. Ir al directorio donde esté instalado Salome, será una ruta del estilo:

/home/pepito/soft/salome/SALOME-MECA-2012.2-LGPL

3. Una vez en el directorio, ejecutar en terminal la orden:

./runSalomeMeca

y aparecerá la ventana inicial de la aplicación.

Salome-Meca: cómo se malla un hypar

Para mallar una superficie hypar en Salome-Meca, seguiremos los siguientes pasos:

Mallado de un hypar con elementos triangulares

1. Entramos en el módulo Mesh.
2. En el Object Browser seleccionar la cara (el paraboloide hiperbólico).
3. Vamos a Create Mesh, y asignamos una triangulación automática, y Cancel en el diálogo que aparece. En la pestaña 1D, seleccionaremos el algoritmo Wire Discretisation y la hipótesis Nb Segments, poniendo 10 como número de segmentos. Aplicamos y cerramos.
4. En el Object Browser seleccionamos la malla, damos al botón derecho y ejecutamos Compute. Si todo va bien, se habrá mallado la cara.

Geometría en Salome-Meca: crear un hypar

Creación de una superficie hypar en Salome-Meca:

1. Crear cuatro puntos no coplanarios: tres en el plano XY y el cuarto más alto.
2. Generar cuatro líneas uniendo esos puntos.
3. Crear una cara (Face) seleccionando las cuatro líneas. Quitar la marca en «Try to create a planar face». El resultado puede verse en la imagen adjunta: es un paraboloide hiperbólico.

El siguiente paso será crear el mallado.