NETS

A THREE-DIMENSIONAL WORLD

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NETS

NETS LINE

One of the main objectives of three-dimensional nets is to give an empty space an element to be the centre of attention, while at the same time enhancing perception of the surroundings.

These three-dimensional structures with a marked sculptural character are focused on using the least amount of material to enclose the most

amount of space, where its social and functional character can be found. They enable construction of ample spaces that enhance free playing, due to their abstract geometries, they develop the imagination and the movement capabilities of the child through experimentation.

Buckminster Fuller. Fly’s Eye / Dymaxion Car, 1980. Photo © Roger White Stoller

NETS

DOMOS LINE

The series of DOMOS (DOMO 3, DOMO 4, DOMO 5) consists of various metal structures of hemispherical shape.They shape a rigid frame to accommodate inside flexible net geometries made of plaited nylon rope.

The use of regular polyhedrons typical of the geological world in the design seeks to form crystalline geometries that are uniformly tensioned

and which take shape unaware of the effects of gravity thanks to their balance in strength.

The nets created by Galopín Playgrounds are noted for their elaborate designs featuring a marked technological component in their development.

Domo 3. Tomillo, Galicia

NETS

DESIGN

Galopín Playgrounds collaborates in its designs with Cipriano Chas Vazquez, an architect specialised in urban design by the University of A Coruña, who is also a visual artists trained between the University of Vigo and Sint Lukas Hogeschool in Brussels.

The design is conceived as a highly-iterating process where an initial trial takes place between the model and the 3D computer render.

Said process refines and modifies the geometry of the net in search of increased harmony and standardisation of the intersections between the different rope courses. During the structural

calculation, which is an essential part of the design, it is modified to optimise the sizing of the structure against the potential overloads that the element will encounter.

Finally, the life-sized prototype enables the trial of the different building solutions or making the necessary readjustments to extract the final measurements of the net to guarantee the quality of the product and go on to mass production.

Model

NETS

DOMO 3

The rigid frame of Domo 3 is made of three tubular arches connected on their upper side by an oculus.

The design of the net arises from an upside down octahedron as the central figure that expands outwards towards the three arches where it is connected to the metallic structure. A rubber surface configures the ground of the polyhedron as the focal space.

The uniform tensioning of the net allows us to attain a clean polyhedral geometry in the set, while at the same time minimising the deformation of the structure under the effect of the overloads that it will encounter, thus preventing potential trappings.

DOMO 4

Seeks increased simplicity in its forms by being configured with three reticular horizontal planes that can be made independently to facilitate its assembly.

A central figure with an octagonal base links the three horizontal planes to raise and hang them inside the metallic structure and thus attain a negative curvature that calls for scaling it and prevents excessive drops under the effect of overloads.

Four diagonals provide rigidity to the set while crossing the upper planes without intersecting with them to facilitate climbing as it if were a liana. The net and the structure form an integral collaboration to ensure the stability and resistance of the set.

Prototype

NETS

DOMO 5

It is made of five larger arches connected to a central oculus that sets itself as a distinguishing feature of the line. The net is made of two planes with opposing curvatures connected by a framework of ropes configured in a radial manner at their connection to the frame so they hold an interior rise along each arch.

Model

A secondary net is highlighted by the use of another colour, it fills the voids created by the five sides of the wall while it limits the drop from the upper plane and leaves a large inner space. Said secondary net seems to float inside the main net since it does not connect directly to the metallic frame.

NETS

In order to evaluate the structural behaviour of the nets, Galopin Playgrounds has collaborated with architect Dr. Juan Bautista Pérez Valcárcel, with professional license no. 428 in the Official Architects Association of Galicia, and a professor at the Technological College in the University of La Coruña and Dr. Manuel Muñoz Vidal, with professional license no. 1220 in the Official Architects Association of Galicia, and a professor of structures at the Technological College in the University of La Coruña.

The network of ropes is connected to the frame using a system of aluminium clamps that go around the metallic tubes and where the necessary tensors are located, in order to achieve the geometry that was initially sought. Due to its high deformability, we used the Artic version 2.97 software which enables the matrix, non-linear calculation of spatial structures with articulated knots.

CALCULATION OF TENSION STRUCTURES

Taking into account the forces transmitted by the network of cables to the frame, it is calculated using the program Metal3D by Cype Engineers, which is a program for matrix three-dimensional calculations for structures with rigid knots. The forces obtained by the network of cables also allow checking the hooks, clamps and tensors to guarantee the entire element.

The structural analysis of the net starts with the process of searching for an initial equilibrium form, formfinding, from an initial design made in a more intuitive way. To that end, a general pre-tensioning is introduced for all the ropes of the net, which will be subsequently discarded, to that the structure’s knots will seek their own equilibrium position and thus attain the most appropriate form with the forces that will affect it.

Structural Idealisation

NETS

Then, a pre-tensing of the structure is performed simulating the use of tensors arranged throughout the net to obtain the initial geometry and a good behaviour based on the forecasted overload as regulated by current legislation UNE-EN 1176-1.

Finally the iterating calculation process takes part in the search for a geometry where both net and metallic frame complement each other and together ensure the stability of the element. The process has just defined an effective structure under the directions of the design’s concepts, introducing modifications that could affect the position of the connection between the net and the structure, and improve the curvature of the two-dimensional nets to reduce the necessary pre-tensioning, etc. Said unit offers a net that is uniformly tensioned and a geometry where the harmony of the element is visible.

Composition of the three-dimensional net course

NETS

COMPONENTS

ROPES

Two types of ropes are considered based on their structural importance inside the element:

A) Ropes with a textile core, for their general use in the net. 6-strand Playground Combination Rope + FC

It is a rope with a 20 mm diameter made with six galvanised steel strands with an axial resistance of 1570 N/mm2, covered with braided nylon. Manufacturer: Randers Reb Internacional A/S.

B) Ropes with a metallic core, for the main

footropes where the tensors are arranged when necessary. 6-strand Playground Combination Rope + IWRC.

It is a rope with a 20 mm diameter made with six galvanised steel strands with an axial resistance of 1570 N/mm2, covered with braided nylon and a metallic core Manufacturer: Randers Reb InternacionalA/S.

METALLIC FRAME

Welded tube made of S 235 JR steel, with a 114.3 mm diameter and a 3.65 mm wall thickness. The metallic structure is subsequently galvanised and lacquered to guarantee a good finish and long lasting protection against corrosion.

HOOKS

The net is connected by hooks at the junction of different rope sections. Stainless steel hooks with an S shape and an 8 mm diameter are used, providing a solution for the junction of two or more sections of rope simply by using a higher number of elements. For standardisation reasons, different types of knots are used to simplify their assembly, even though their number could be increased if necessary as a function of the forces obtained in the calculation.

Pol. O Acevedo, Parcela A – 15185 Cerceda, Spain | +0034 981688070 | www.galopin.es

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