EMERGENT TECHNOLOGIES & DESIGN CORE STUDIO 1
Lorenzo Franceschini Hazar Karahan Antonia Moscoso Arnold Tejasurya
Abstract The project involves the development of a material system that explores the structural as well as the spatial quality relation of the strong and sometimes unavoidable dualism between wooden components and fabric. The fairly easy system logic is comprised of compression components held in place by geometry, self-weight, and a fibreglass layer working in tension. The wide possibility of global geometry realisation makes this process very flexible. However, the drivers for the final design solution include weather parameters on the site, namely wind direction and intensity, dry bulb temperature and sunlight exposition, in addition to the main focus that aim at enhancing spatial qualities of the pier. Different sets of experiments investigate geometrical possibilities and structural capacities of the system, in order to reach a final design –and process rationality- able to provide improved quality for users as well as construction feasibility. A final solution is reached, combining voronoi volumes as a compressive inner layer and an outer layer of fibreglass as stiffening and tensile skin, able to give its contribute to the area along the 24 hours.
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Contents 0.0 Introduction 2 1.0 The system’s logic 1.1 Environmental conditions and system’s aim 3 1.2 Geometrical parameters 6 1.3 The membrane ‘s role 7 2.0 Experiment 1: 2.1 Spatial configuration: iterations 11 2.2 Structural performance 13 2.3 Differentiation: gradient strategy 15 2.3.1 Light analysis 17 2.3.2 Wind Analysis 18 2.4 Fabrication considerations 21 2.5 Conclusions 23 3.0 Experiment 2: 3.1 Hierarchy and differentiation 25 3.2 Structure 30 3.3 Wind analysis 32 4.0 Conclusion 33
CORE STUDIO 1 1
0.0
Introduction
The project seeks to develop a surface that can act as a mediator of the environmental conditions present at the site by creating a flexible material system that enables differential permeability of light wind and view in specific location. The project relies on the hypotheses that by creating a material system composed by wood bricks, in compression and a fabric membrane, that acts as the mortar, it would be possible to control both the global form by manipulating the brick’s geometry as well as the permeability. An initial set of physical and digital experimentations were conducted to identify the parameters responsible for the overall curvature and the structural stability of the system. The deducted rules are then applied in a top down approach to define the global form. Different strategies to increase the differentiation of the pavilion are also explored. Wind and light analysis are also implemented to further evaluate the performance of the proposal. At this stage, concern with the clearness of the drivers for the configuration of the initial experiment as well as spatial hierarchy leads into reviewing the system’s logic, the component’s geometry and the global form. Therefore, a second morphology of the system based on further research on compression structures attempts to tackle this issues.
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1.0 1.1
THE SYSTEM LOGIC Environmental conditions and system aim
The project’s principal objective is to turn the Masthouse Terrace pier into a site that provides multiple spatial and programmatic experiences to it s users by presenting a gradient of environmental
conditions. As a starting point, the environmental conditions of the pier were studied and three distinct spatial arrangements were defined:
1. The shelter: a space that responds to the low outdoor comfort that characterizes the pier especially between November and April protecting from the wind and the rain while allowing the light from the sun. The shelter Outdoor Comfort Extremely cold
Jan
Feb
Cold
Mar
Outdoor Comfort LONDON/Gatwick_GBR
Comfortable
Apr
May
Hot
Jun
hours
Extremely hot
Jul
Aug
Sep
Oct
Nov
39%
Dec
1 Jan 7:00 - 31 Dec 19:00
Average rain/ month 30
13
days
0
2. The partial shaded: a space that deals with the predominant winds from the south and south west, and protects from the rain and the sun. Partially shaded
Sun exposure
E
environmental parameters 4%
N
6%
8%
sunlight
12% S
10%
rain wind
< 71 <=3.10
4.54
5.98
7.42
8.86
10.30
632
11.74
13.18
14.62
1594 16.06
Oct to April 8 am - 6pm
wick_GBR 15APR 19:00 election Applied: Wind Speed > 3
hours
17.5 <=
W
m/s
CORE STUDIO 1 3
people
m/s 17.5 <=
Predominant wind
16.06
m/s 17.5 m/s
14.62
17.5 <= 16.06
13.18
14.62 13.18
11.74
11.74
11.74
10.30
10.30
8.86 7.42
8.86
5.98 4.54
< 3.10
7.42
<=3.10
Wind Rose LONDON/Gatwick_GBR 15 OCT 7:00 - 15APR 19:00 Conditional Selection Applied: Wind Speed > 3 m/s
Wind Rose LONDON/Gatwick_GBR 15 OCT 7:00 - 15APR 19:00 Conditional Selection Applied: Wind Speed > 3 m/s
5.98 4.54 <=3.10
Wind Rose LONDON/Gatwick_GBR OCT 7:00of- 15APR 19:00 river while 3. The â&#x20AC;&#x153;inside outâ&#x20AC;? that allows the users to have direct contact with15 the view the Thames Conditional Selection Applied: Wind Speed > 3 providing partial shelter from rain. m/s
Inside out
An initial zoning of these spatial conditions was set in which the user would experience a gradient of contact with the outside. The shelter as a larger waiting area next to one of the embarking points in the area of more sun exposure of the the shelter
inside out
pier, the transition space that allows the view of London in both directions and a seating area next to the ramp were the surface is located towards the south to provide shelter from the predominant wind. partially shaded
view
embarking
embarking view
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To achieve a continuous surface with differential porosity that can modulate the environmental conditions, this projects focuses on the development of a material system composed by an aggregation of timber bricks, compression elements, and an outer layer of fabric membrane that has the role of the mortar. The permeability gradient of light would be accomplished by the interaction of the removal of cer-
tain wooden bricks and a variation of the properties of the fabric membrane. In the system, there is no joint in-between the units, and the geometry of the units determines the curvature of the assembly. The systemâ&#x20AC;&#x2122;s stability relies both on the friction between the components and the stiffness of the membrane.
System logic diagrams plywood bricks components
fabric membrane
angles control curvature
no joint between the bricks
membrane in tension
CORE STUDIO 1 5
plywood in compression friction between the plywood elements removal of the bricks to modulate the environmental conditions
1.2
Geometrical Parameters
The system’s brick component can be described by five geometrical parameters that inform the global form: 1. The angle between upper and lower pieces responsible for the curvature; 2. The angle of the horizontal plane of the component responsible for introducing torsion; 3. The angle on the lateral sides of the compo-
nent controls the horizontal curvature of the assembly, 4. The height of the component has an impact both on the number of pieces and the smoothness of the curvature; 5. The width of the unit ensures the friction between the components.
α angle - curvature
β angle - twisting
α
ω
h
10
β a
b
the Component
ω
ω angle - horizontal curvature
h - number/ smoothness
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1.3
The membrane Role
CORE STUDIO 1 7
While the brickâ&#x20AC;&#x2122;s geometry controls the global shape, the fabric properties are related to the stability of the assembly; it also defines the maximal size of areas with no bricks and enable to create different porosity conditions for light and wind. Physical experiments with different fabrics showed that in order for the system to work, the relation between the elasticity/stiffness of the fabric and the weight of the bricks has to be calibrated. Besides, the membrane also enables to introduce variation on the support conditions of the assembly, in other words a cantilevering condition is feasible .
An initial set of experiments sought to identify the distance between the bricks and the structural performance of the membrane, by shifting the bricks and analysing the minimal contact between units. By studying both the displacement of the overall surface as well as the force flow in the areas with no bricks, it is noted that the minimal contact area between two bricks should be 50%, however it was not possible to establish the maximum span of the bricks that would guarantee tension on the membrane and not create wrinkles.
removal of the bricks to modulate the environmental conditions
Displacement on z : area of contact 25% vs 50% LOAD: gravity Wood: Fabric: 750 MPa Support condition no degrees of freedom.
area of contact: 25%
PLATE DISP: D(XYZ) mm 6.12x10¯ ¹
0.00x10º
area of contact: 50% Force : area of contact 25% vs 50%
1. Forces out of the projection of the support , generating bending moment
PLATE FORCE: (N/mm) 9.60x10¯³
3.70x10-�
-1.14x10¯² 2. Forces inside of the projection of the support , no bending moment .
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sile
In terms of the permeability of the assembly, the different properties and types of textiles can be defined as the following. Various textiles give a good variation of behaviours of dealing with environmental factors. Light permeability, wind-
proofness and waterproofness are the main parameters that should be analysed in order to make the choice about the correct typology of material to use.
Net fabric featuring the same tensile strength in both directions. It would allow a total permeability for what light, wind and rain are concerned. Control over the weather can be achieved through layering of the fabric.
net fabric same tensile strength
dense net same tensile strength
dens vertica strengt horizon
Dense net fabric featuring the same tensile strength in both directions. It would allow a total permeability for what rain is concerned, while it is able to slightly reduce wind and light filtration. Control over the weather can be achieved through layering of the fabric.
dense net
CORE STUDIO 1 9
same tensile ďŹ ber comstrength posite fabric more vertical tensile strength rigid (non-elastic)
dense net vertical tensile strength polyester horizontal elasticity fabric same tensile strength rigid (non-elastic)
Dense net fabric featuring different tensile strength in vertical and horizontal directions, in order to adapt it better to the outer of the structure. It would allow a total permeability for what light, wind and rain are concerned. Control over the weather can be achieved through layering of the fabric.
dense net vertical tensile polyester strength fabric horizontal elasticity same tensile strength
custom fabric more vertical tensile
cus fab more streng variab
ile
ngth
net fabric same tensile strength
dense net
dense vertical strength horizont
same tensile strength
Fiber composite fabric with main tensile strength directed vertically. Fibers (material and number to be defined by structural analysis) are laid in between two layers of transparent film (e.g. Mylar). Wind and rain could be totally blocked by the waterproofing film that could eventually allow light to filter through thanks to the transparent properties dense net same tensile ďŹ ber comstrength posite fabric more vertical tensile strength rigid (non-elastic)
dense net vertical tensile strength polyester horizontal fabric elasticity same tensile strength rigid (non-elastic)
cust fabr more v streng variabl
Polyester-like fabric with same tensile properties in all directions. Translucency would partially allow light filtering.
dense net vertical tensile polyester strength fabric horizontal elasticity same tensile strength rigid (non-elastic)
custom fabric more vertical tensile strength variable horizontal ten-
Custom made fiber composite fabric (laminated) with fibers placed according to the structural needs and to aesthetic purposes; transparent film layered according to environmental factors to be controlled
custom fabric more vertical tensile strength variable horizontal ten-
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2.0 EXPERIMENT 1 2.1 Spatial configuration: iterations After defining the systemâ&#x20AC;&#x2122;s logic and setting the environmental targets of the three spatial arrangements that are contemplated by the project a set of digital experiments explored a variation in the support geometry as well as in the curvature of the assembly and a gradient in the number of pieces or in the curvatureâ&#x20AC;&#x2122;s smoothness. As a starting point for this experiments, a set of section curves was established
for both the shelter and the partially shaded space which was understood as a cantilever configuration of the system, limiting the maximum height of the spaces. Then, establishing the spatial outcome of circulating from a space where the curvature went from smooth too rough fragmented or continuous supporting geometries where studied, creating a series of iterations.
The Shelter : iterations
Conditions: controlled wind partially shaded sunlight no rain
view
3.0m 2.5m
2.5m
3.5m
Support geometry
Height differentiation low
Number of pieces
continuous
A1
fragmented
A2
3.5m
high
low
A1.hlh
smooth
CORE STUDIO 1 11
rough
fragmented curved
A3
A2a.hlh
A2b.hlh
The resulting configurations showed that on the shelter the variation from a smooth to a rough curvature wasnâ&#x20AC;&#x2122;t an a successful strategy to introduce differentiation, and that fragmenting the supporting geometry would allow to direct airflow into the shelter. In the partially shaded space it was noticed that the curvature of the supporting geometry can not
be greater than the curvature in the vertical plane, therefore the asymmetrical seating are, iteration C3 hl, was further developed. However, it needs to be pointed out that hierarchy as well as the programmatic variations are weak in both configurations and that this is reviewed in experiment 2.
The partially shaded : iterations Conditions: partially wind partially shaded sunlight partially rain
3.5m
3.0m wind
river
Support geometry
wind
3.0m
river
3.5m
Height differentiation high
low
high
low
high
low
high
low
2 seating areas
Number of pieces
C1
smooth
rough
C1.hl
C1.hlh
C1.lhl
C2.hl
C2.hlh
C2.lhl
C3.hl
C3.hlh
C3.lhl
central seating areas
C2 1 seating area
C3
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2.2 Two different approaches are contemplated of how to best study the structural behaviour of the material system. The first approach considers the system as a combination of structural ribs and envelope where some bricks are actually fundamental for load bearing where as others contribute by the lateral compression but can me removed. Digital modelling was used to determine the maximum span between the structural ribs however this approach is not considering the membrane’s contribution nor the lateral transmission of the loads. For instance in the cantilever configuration the overall thickness of the surface increased to 150mm to reduce displacement. Therefore, a second approach considers the system as a composite shell, and it is simulated by series of plates with two different material properties acting together, and the structural role of the membrane is confirmed
Structural performance when the minimal necessary thickness of the brick is reduced to 50mm. The results presented below show both configurations, cantilever and arch in the second approach and the displacement of the plates only considering self load. Wind loads have not been implemented in these tests. The tensile membrane is considered as mesh with a Young’s Modulus of 700MPa. In the cantilever configuration is important to notice that further reducing the thickness of the bricks from 50mm to 25mm increases the maximum displacement. In the arch configuration the maximum displacement is perceived in the upper part of the arch.
Material Properties Membrane *modulus: 700 MPa *poisson’s Ratio: 0,35 *density: 6,7 e -10 T/mm3 *specific Heat: 1,6 e 6 J/T/C Wood units *modulus 10500 MPa *Poisson’s Ratio: 0,3 *Density: 5,5 e -10 T/mm3 *Thermal Expansion: 3,5 e -6/C
CORE STUDIO 1 13
Support conditions node attributes translation rotation X fix X fix Y fix Y fix Z fix Z fix
Cantilever displacement analysis Material Thickness Membrane: 1mm Play wood: 25 mm
Material Thickness Membrane: 1mm Play wood: 50 mm
Arch displacement analysis
Material Thickness Membrane: 1mm Play wood: 25 mm
Material Thickness Membrane: 1mm Play wood: 50 mm
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2.3 Three different arrangement strategies are applied on the global surface in order to manipulate the openings. The strategies depends on the zoning of the area by changing the width of the wood brick units. The first strategy is based on having one single zone with the same width of 600 mm of the units everywhere. The second option is dividing the global surface into two different zones and applying different width in each zone. The last approach involves the process of creating the global surface by hav-
CORE STUDIO 1 15
Strategy 1
Differentiation Strategy ing a set of three width, 200 mm, 400 mm and 600 mm and randomly distributing on in. From strategy one to strategy three the total number of the units slightly increases. The aim of applying various number of strategies seeks to investigate how to control the light at the inner space for the users, even though the results had similar effects. The width of the units , including the shortest width which was 200 mm, were too big to create a significant differentiation.
Strategy 2
Date: 15 April - 1pm
Strategy 3
Plywood components size: average height 700mm width 600mm thickness 50mm TOTAL: 592 pieces
Strategy 1 all pieces same width
6 pieces x 1sheet approx = 100 sheets
Plywood components size: average height 700mm width 600mm / 400mm/20mmm thickness 50mm TOTAL: 635 pieces
Strategy 2 zones with 3 widths
6 pieces x 1sheet approx = 105 sheets
Plywood components size: average height 700mm width 600mm / 400mm/20mmm thickness 50mm TOTAL: 725 pieces
Strategy 3 3 widths
6 pieces x 1sheet approx = 120 sheets
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2.3.1
Light quality
CORE STUDIO 1 17
The following experiment deals with the fabricâ&#x20AC;&#x2122;s shading qualities. As previously anticipated, the intention is locally remove a certain number of pieces in order to attain different shadowing patterns. In this way, the fabric working on the outer layer of the surface, not only bears structural characteristics, but also performs as filter where the component is removed.
This experiments only takes in consideration net-like fabrics, since the chances given by the layering opportunity provide more variations in patterns. By acknowledging the different outcomes, itâ&#x20AC;&#x2122;s then possible to plan which kind of result is wanted in a certain area of the structure.
Net fabric 1x1 mm 1 layer
Net fabric 1x1 mm 3 layers
Net fabric 1x1 mm 5 layers
Net fabric 4x4 mm 3 layers
Linen net 0,5x0,5 mm 1 layer
Linen net 2x2 mm 1 layers
2.3.2
Wind analysis
Wind analysis is used to determine both the pressure on the surface and wind flow trough the system. The experiments aimed at understanding the balance between reducing the pressure by removing bricks and correct dimensioning of the openings to avoid wind tunnelling. An initial set of tests aimed seeks the relation between the curvature and surface
pressure, and it is confirmed that the pressure is higher when itâ&#x20AC;&#x2122;s normal to the wind. Porosity on the surface also reduces the pressure on it effectively; with the right dimensioning of openings it is also possible to modulate wind, in order to decrease its speed to light breeze or block it.
3 Components Surface Pressure Pressure (Pa) 30
3 Components Surface Pressure Pressure (Pa) 30
15.067
15
3 Components Surface Pressure Pressure (Pa)
30 15 0
15.067 2.452
Degree (Xo) 75o
90o
15.067 6 Components Surface Pressure 3 Components Surface 2.452
15Pressure (Pa) 30 0
Degree (Xo) 75o
90o
6 Components Surface Pressure Pressure (Pa) 30 0 15
2.452
16.573
75o
Degree (Xo)
90o
6 Components Surface Pressure Pressure (Pa)
30
4.263
16.573
15 0
Degree (Xo) 75o
90o
4.263
16.573
9 Components Surface Pressure 15Pressure (Pa) 30 0
30.129
75o
4.263
Degree (Xo)
90o
9 Components Surface Pressure
6 Components Surface Pressure (Pa)
30.129
30 0 15
75o
Degree (Xo)
90o
9 Components Surface Pressure
Pressure (Pa)
5.324
30.129
75o
90o
30 15 0
Degree (Xo) 5.324
15 0
Degree (Xo) 75o
90o
75o
90o
5.324
Degree (Xo) 0
Pressure on 9 Components Surface
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CORE STUDIO 1 19
The surface without porosity will has very high pressure, or even creating parachute effect.
With creating porosity in the surface, will reduce the pressure and also can allow comfort breeze to pass through instead of heavy wind.
High porosity with small holes allows to reduced the pressure however if the holes are to small it blocks the wind.
Less porosity with bigger holes reduces the pressure considerably creating a comfortable breeze
The global geometry is analysed through CFD testing software using 5m/s wind speed in order to understand the surface pressure values. The results are not as expected. Even though the surface pressure is slightly reduced, due to the geometry relation between the structure and the existing ramp on the pier, a Venturi effect is created increasing the wind speed, generating a non-comfortable zone where the sitting area was planned.
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2.4 At the point of an analysis that takes into consideration the fabrication technique for the system developed so far, some issues become visible. The structure of 50 mm plywood plus an outer layer made of fabric, if examined step by step from the fabrication to the construction stage, it lacks in some phases. The matter of featuring all different pieces, though, has not been intended as an issue, since it would be easily solved by using a 5-axis mills to produce the components; pieces that would have to be obtained from a single 50 mm plywood sheet, resulting in a lot of weight. This last characteristic leads to the set of issues related to the eventual construction process on site. The scheme on the bottom explains the phases that would lead to the realization. After the lowest component has been fixed to the
Fabrication considerations ground via steel brackets, the pieces are laid one on top of the other, one by one, while on the back side the fabric is attached to the pieces. When the pieces start to be laid at a certain angle and height, the use of scaffolding is necessary in order to sustain the wooden components while the fabric is positioned. At last, depending on the geometry of the structure, a cable might become necessary in order to help maintain constant compression: passing through all the last-row components, it would then be tensioned and fixed to the ground, assuring to keep in compression the pieces at all time.
System 1: 50mm plywood + membrane cable to prevent the wind from lift4 ing in the structure a cable is passed through the last piece to and fixed to the ground. fabric 3 when all the pieces are into place the fabric is laid and attached to the components
temporary 2 fibers on the back and
scaffoldings to keep the pieces in place awaiting the fabric
CORE STUDIO 1 21
foundation 1 steel â&#x20AC;&#x153;Lâ&#x20AC;? profiles and
horizontal plate to clamp the wood component
considerations: weight / friction component 600x400x50 mm volume v= 0.012 mÂł mass m=8.4 Kg
In order to partially overcome some of the issues faced with the previous system, changes are introduced. The complexity of fabrication increases, even though it is not where the interest in enhancing the structure fosters: instead of a single thick component, a box-like element is introduced. The overall thickness of the section increases, providing eventually structural depth and more surface contact between the components, but the overall weight decreases, having a structure 16% lighter (the weight could be further reduced, by decreasing the thickness of the plywood with which the box is made). Using these box-like components, assuming that the construction phases to lay the fabric on the outer face are the same, would eventually lead to avoidance in using scaffoldings.
The potential of being able to remove one face of the box during construction would lead to the possibility of simply clamping one component to the next one. In this way the placing of the fabric on the back could be implemented. Also in this solution, if required, a cable can be pierced through the last-row component and fixed to the ground at the sides n order to provide constant compression in the structure. The downsides of this system are...
System 2: 15mm plywood box + membrane 4
3
temporary Fibres on the back and clamps in the inner side of the boxes to keep the pieces in place awaiting the fabric. 1
2
considerations: weight / friction component box 600x400x150mm thickness 15mm volume v= 0.0117m続 mass m=7.1 Kg
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2.5 Conclusions
CORE STUDIO 1 23
On the architectural side, the system composed by boxes shows some interesting potential together with weaknesses. As the physical model displays, the possibility of integrating lighting effects within the components themselves adds quality to the system. The effects created by the different visual thickness of the components, the closed ones opposed to those with a hole, opposed to the missing pieces, contributes to an overall differentiation of the surface. The construction system is still eventually the hardest part to solve. The double degree curvature of the structure does not allow an easy laying of the fabric. The larger the fabric piece, the more difficult would be to adapt it to the back of the wooden components. In order to solve this problem there could be two different ways. The first one and probably more complicated
would be to create a custom composite fibre reinforced fabric moulded exactly as the outer surface to be covered. As introduced earlier in the fabric chapter, this solution would allow a control of nearly 100% of different important features as wind/light/air porosity and structural performances. The second way of overcoming the problem of the fabric laying, would be to use several layers of fibre glass stripes, in order to obtain a uniform outer surface. The level of permeability of the membrane could be accurately controlled during the laying process.
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3.0 3.1
EXPERIMENT 2: Spatial hierarchy and differentiation
Proposal 1 - still not conceptually detached from the previous version
Proposal 2 - complex in realization and too fragmented
CORE STUDIO 1 25
The issues embedded in the system developed up to this point lead eventually to a necessity to introduce some changes in it. The weak architectural result needs to be rethought in more interesting application, as well as the whole system needs to be revised in order to achieve the goal. The system logic itself is maintained as it is, with the inner layer of wooden components that work in compression and an outer layer of fabric that work in tension. Everything that has been so far understood from the site condition, as well as the overall
goal of providing three spatial conditions is kept in mind for these further steps of the design process. In order to reach a distribution of the structure that would define the desired spatial conditions a series of tests are carried out. Among all, the one that better interprets the wanted requirements is chosen for development. It indeed clearly subdivides the pier surface into three: a wide waiting area on the left, a central part that has open view on the Thames and a third one that is more protected from the southern winds.
Proposal 3 - clear definition of three spaces, potential of creating differentiation even by keeping the same language
The geometrical logic of the initial design proposal was based, as extensively explained in the first chapters, on the quadrilateral shape of the components, creating a simple grid on the surface. The introduction of the varying width of components did provide some variation to the system but at an overall look did not provide any interesting architectural outcome. A more uneven subdivision may come from a voronoi partitioning, and although the control over this type of tessellation might not be as definite as the previous one, it would allow a more precise and ruled logic over the density -and consequently the size- of the cells in specific areas. This concept is explained below, taking
a sample square area. The control over the cell density allow to have a variation in their geometry where desired, in this case defined by a point. The definition of different areas with smaller cells also help defining which component are to be removed in order to provide a certain required spatial quality. The driver that instead rules the positioning of those points on the surface at a bigger scale are those areas of some particular interest. For instance, they could be positioned on the hypothetical line that connects the sitting place with a particular surrounding landmark that is wanted to be visible while sitting.
The surface is populated with points that define the voronoi cells
Where needed areas of higher density of cells are generated
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Desired cells around that region can be deleted
Non uniform thickness of the components is then implemented
CORE STUDIO 1 27
The geometries are applied to the pre-defined surface
With the system logic also the distribution and the geometry of the overall spatial configuration slightly change. The first chapter deals with environmental parameters that have been used as initial drivers to shape the first set of geometries. For this further development the same concepts are taken into account, together with the same goals of providing three different spatial conditions. Due to the geometry of the site -the access ramp, a wider space and a thinner space- and its restrictions -the ramp and the two accesses to the ferries- the areas assigned to the waiting/sitting areas do not vary. What does change is how the space is covered by the structure. There are no gaps or distinction between the three spaces, even though a strong
A
View towards London City
B
View towards the river
C
Morning light
D
Sky view
C
C
curvature discontinuity applies from one another. The planned sitting areas are generated by a continuation of the lower part of the structure, where some voronoi extrusion provide different levels of seating. More importantly, the actual differentiation between one zone and the adjacent one relies on the distinct positioning of focal points. The previous paragraph introduced the concept of points between the user and certain defined foci, translating into a densification of components -with a consequent removal of some of them. A selection of views per each of the three area is then determined.
C
D A
D
D
B
Definition of focal points related to surrounding environment
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the shelter
embarking
CORE STUDIO 1 29
Section A
inside out
partially shaded
embarking
view
Section B
3.2 Structure Concerning the structural aspect of the new proposal, the concept behind it still remains the same of the previous version. The voronoi components that constitute the structure are disposed following the concept of vaultâ&#x20AC;&#x2122;s bricks. As in the previous variant the compression behaviour of them is of key importance for the global stability of the intervention. A slight difference lays in the presence of the layer of fibre glass on the outer part of the surface, instead of a simple membrane, that would eventually lead to an increase of
general stiffness, allowing better performances, especially under wind and accidental loads -as the strong vibration induced by the movement of the pier. As shown in the section diagram below, another feature that is introduced comprises the thinning of the higher components. The advantages of this operation can be of total weight reduction as well as a easier installation process.
Reduced thickness
Removed pieces Outer fiberglass layer
Blocks in compression
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Material Properties Membrane *modulus: 700 MPa *poissonâ&#x20AC;&#x2122;s Ratio: 0,35 *density: 6,7 e -10 T/mm3 *specific Heat: 1,6 e 6 J/T/C Wood units *modulus 10500 MPa *Poissonâ&#x20AC;&#x2122;s Ratio: 0,3 *Density: 5,5 e -10 T/mm3 *Thermal Expansion: 3,5 e -6/C Support conditions node attributes translation rotation X fix X fix Y fix Y fix Z fix Z fix
Wood Units
Membrane
displacement analysis
Material Thickness Membrane: 1mm Play wood: 25 mm
CORE STUDIO 1 31
Material Thickness Membrane: 1mm Play wood: 50 mm
3.3 Another reason for the change in geometry derives from the partial failure of the previous wind analysis. With the definition of the new global surface another CFD analysis is carried out, trying to reduce the wind channelling so as to provide area subjected to lower wind velocities, resulting in higher comfort
Wind analysis for the users. The values of the pressure on the surface decreases in comparison to the previous analysis. This outcome is able to give proof that this last global geometry has a better performance when hit by the southern winds.
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4.0 Conclusions
CORE STUDIO 1 33
This project is an exploration of a composite material system capable of mediating the environmental conditions in order to create a gradient of spatial conditions with programmatic flexibility. In order to achieve this goal, the project studied the combination of two materials with very dissecting properties wood brick act as compression elements jointed by a fabric membrane in tension. The interaction between these two materials allows control of the global form as well as of the permeability of the assembly by the removal of the wooden bricks in determined areas allowing the membrane to act as a filter. Initial experiments conducted enabled the understanding of the relation between the bricks geometry and resulting curvature, and structural analysis demonstrated that this composite system has higher tensile strength than a regular masonry system. On the first attempt to scale the system up a series of weaknesses became evident. First of all, the bricks were also scaled up acquiring larger dimensions, and the system lost the balance between the size of the openings and the environmental conditions. The overall proposal failed on controlling the interaction with the wind and the shadows became large patches. Secondly, in terms of fabrication, issues related to the size of the wood panels, their weight and the construction sequence were also noticeable. Thirdly, the overall proposal lacked hierarchy and clearness on the drivers for introducing differentiation, as result a very homogeneous surface was perceived. This issues led into reviewing the system, and a second experiment was conducted changing the geometry of the wooden bricks as well as establishing the composite as a combination of fibre glass and thin bricks based on the study of the vault compressive structures. This exploration relied on the hypotheses that by increasing the stiffness of the membrane the second thin layers of bricks used on vault structures could be replaced by fibre glass. This second morphology attempts to set more clearly three spatial conditions: a waiting shelter, a space covered from rain where the user can face the Thames river and a space that faces the ramp protected from the predominant wind. Besides, clearer rules were defined to determine the dimensions of the bricks where more porosity is required. Even though the second experiment sets a clearer path into achieving a gradient of environmental conditions, it requires further development on the study of permeability of the fibre glass reintroducing the concepts studied with different fabric membranes. Moreover the construction sequence of the system also needs further exploration.
ARCHITECTURAL ASSOCIATION SCHOOL OF ARCHITECTURE GRADUATE SCHOOL PROGRAMMES
COVERSHEET FOR SUBMISSION 2014-15
Emergent Technologies and Design Term 1
Core Studio 1 19.01.2015
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Lorenzo Franceschini Hazar Karahan Antonia Moscoso Arnold Tejasurya