PROJECT 2A – MAKE OR BREAK – NANOTECHTURE
Craig Gregory, Callum Draffan, Munsawar Jalil and Nicholas Onions
1
TABLE OF CONTENTS INTRODUCTION ………………………………………………………………………………………………………………….. 1 TABLE OF CONTENTS ………………………………………………………………………………………………………….. 2 OVERVIEW ……………………………………………………………………………………………………………………....... 3 PROGRAMME TIMELINE …………………………………………………………………………………………………….. 4 PRECEDENT STUDIES 1. BUILDING FORMS ……………………………………………………………………………………………………… 5 2. BRIDGE STRUCTURES ………………………………………………………………………………………………… 6 3. BRIDGE STRUCTUES 2 ……………………………………………………………………………………………….. 7 4. ENSION AND COMPRESION ………………………………………………………………………………………. 8 CONCEPT AND INITIAL DESIGN IDEAS ………………………………………………………………………………… 9 MODEL DEVELOPMENT 1. MODEL DEVELOPMENT 1 ………………………………………………………………………………………… 10 2. MODEL DEVELOPMENT 2 ………………………………………………………………………………………… 11 3. MODEL DEVELOPMENT 3 ………………………………………………………………………………………… 12 DESIGN DEVELOPMENT ……………………………………………………………………………………………………. 13 MODEL REVIEW ……………………………………………………………………………………………………………….. 14 OTHER GROUPS EVALUATION 1. GOOD EXAMPLE ……………………………………………………………………………………………………… 15 2. BAD EXAMPLE …………………………………………………………………………………………………………. 16 3. AESTHETIC EXAMPLE ………………………………………………………………………………………………..17 TECHNICAL DRAWINGS (GROUP I) ………………….………………………………………………………………….18 BIBLIOGRAPHY …………………………………………………………………………………………………………………. 19
2
OVERVIEW Objective: To design and build a lightweight structure that holds a 1kg bag of sugar, working with the constraints below. As a group you are only permitted to use the following materials. • 3mm wooden dowels • Glue • String • Tissue paper Constraints: • The base is to be no bigger than 600mm x 600mm (B) • The sugar must be supported 500mm off the base (V) • A clearance of 400mm x 400mm will be maintained as illustrated in Fig 1 (H) • The sugar must be cantilevered a minimum of 400mm from the edge of the structure (C) • No part of the structure can exceed the base • Only materials listed above may be used • The base must not be fixed down Learning Outcomes: • Recognise factors used to establish the fundamental link between design and the technological discipline involved in design • Identify simple processes related to Architectural Technology as the technology of Architecture ontologies, forms, functions, concepts and contexts • Identify concepts, principles and theories associated with the selection of building materials & Construction methods • Develop the use of three-dimensional modelling • Recognise the potential for project feedback to generate future improvements
3
TIMELINE PROGRAMME Week 01 - 23/10/17 • • • •
Brief Issued – before visiting “Yorkshire Sculpture park“ Locate and collate with all individuals in group. Individually think of concept ideas and provide evidence of where we got them for input into group work and discuss Inspiration Research
Week 02 – 30/10/17
• Group meeting/discussion. • Collecting previous ideas/designs/concepts from all of the group. • Discuss and implement building strategy for initial concept design. (original spaghetti pieces) • Design Development • Swapping concepts and overall design layouts. (Sketch book drawings and ideas) • Looked into technical side of structures. • Sheer and Bending moments, where the weak points in a cantilever would be. • Architect & engineers pocket book, reference point and ideas to use. • Start construction of “spaghetti Frames” • Varied trusses ideas and designs original concept idea and • Constructed mock Spaghetti model
Week 03 - 06/11/17
• Final design construction of a dowel model of the concept design & tested. • Single dowel bars, String & glue. • 1:50 scale • Made Final model construction for preparation on Monday • Full scale model created, in modular components before final completion. • Bracing and joining at node points. • Tested model.
Week 04 – 13/11/17 • • •
Final test model assement. Evaluation of other groups models Finalisation of overall project report.
4
PRECEDENT STUDIES – BUILDING FORMS In 2007, the “Skywalk” at Eagle Point was constructed. This skywalk is a 10ft wide horseshoe shaped glass bridge, cantilevering out 70ft from the rim of the Canyon. The support arch is built using 2inch thick steel plates sandwiching the 2.8inch thick glass floor made using 5 layers of glass, this structure of the cantilever will prevent the skywalk from warping or bending under heavy loads. Beyond the rim of the canyon, the cantilever extends around 100ft inwards, with two steel beams placed parallel to each other to support the structure, and is then held using 94 bolts, which have been drilled 46ft into the earth in order to anchor the cantilever. Visualisation of this can be seen in figure 2. (NBC, 2006)
Fig 01
From this cantilever study we can take forward the idea of having a heavy anchor on the back end of the cantilever in order to counterbalance the heavy loads. This further lead us to looking into tension ropes on the back of the model in order to help the cantilever withstand any load that was placed at the tip; in the case of the project, a 1kg bag of sugar. The inspiration for our model was originally found from building structures which utilized the cantilever structure. We felt that they’re a basis for our model and could be evolved further in the design process. This lead us to look at the Suburbia Tower designed by architect, AARON BERMAN. This tower utilizes the similar cantilever structure which we intended to include on our model, this being having part of the cantilever protrude from the back of the stem, and for this section to be weighted in order to withstand large amounts of weight in the accessible cantilever side
Fig 02
We then continued further research onto the building forms and ways of counterbalancing the load to be placed at the tip of the cantilever. Figure 3 gives you a visual representation of a similar idea we had in mind for the tension ropes located at the back of the cantilever. The idea of the minimalistic design also caught our attention and wanted to be something we would portray in our final design. Fig 04
Fig 03
5
PRECEDENT STUDIES – BRIDGE STRUCTURES Forth Bridge (Fig 05-06) We used this as a precedent study to look into the where the node points of any possible bracing would and could be located in relation to our design, especially as this was deemed as a cantilever-bridge. This bridge having been designed and constructed in the 1800’s; would of have had to of been created as simply as possible and with no intricate steel detailing needed. A perfect choice for our group as we were using basic materials with limited engineering experience. Charles Kuonen Suspension Bridge (Fig 07-08) When looking into this idea as a precedent study, we considered the idea of the length of the bridge; with a consistent live load being applied by the travellers. As well as the seasonal snowfall every winter, and looking into greater detail into how Swissrope and Lauber cableways designed and created it.
Fig 05 – Firth of Forth Bridge, Scotland.
Mostly we considered the structural integrity and the layout of the steel framework, as well as how it distributed the weight throughout the entirety of the bridge’s length alongside the rigidity of its frame; and looking into greater detail into how it removed any “sway-motion” during bad weather conditions and high winds, which could lead into structural failure.
Fig 06 – Original Technical Drawing (1882) Showing structural stress points.
Fig 08 – Charles Kuonen Suspension Bridge, Switzerland.
Fig 07 - Charles Kuonen Suspension Bridge, Switzerland.
6
PRECEDENT STUDIES – BRIDGE STRUCTURES 2
Fig 10a
Fig 09
Using the Architects pocket book, we used this as a reference for our bending motions and beam formulas concepts along the main superstructure. To better understand the forces in motion that would be needed.
Fig 10
Using the Structural Engineers pocket book, we used this to look for ideas for our bracing support, along the main superstructure. We settled on a Pratt truss (Cantilever) and a Howe truss (Mast).
Fig 10b
Fig 10a was what we were hoping to achieve as a final result. Keeping in mind the need for suspension lines alongside fixed bracing to the overall finished design. Fig 10b were the possible girder designs we were going to use for our overall finished concept design.
7
PRECEDENT STUDIES – TENSION AND COMPRESSION For this stage of the study, we looked into how motions and the forces involved would affect the structure and node points of the final design. Keeping in mind the potential weak points, where these motions would greatly affect the structure and how best to contest these motions into providing a more stable structure. When looking at figure 11 we considered where the compression and tension points where to be located on our own canter-lever model and in doing so we could look in greater detail, where the structural weak points would be located. By doing this we could reinforce those areas with sufficient bracing and “adhesive” methods, to ensure it would not break under a imposed load. Figure 12 was an example of Inertia in motion, that was provided by our tutors during a seminar session. However it helped us to understand the need for balance and proportion in our cantilever construction. Figure 13 we used for a general concept for the formwork layout; the location and types of bracing needed for our model. Looking at the best method in making the frame support and how to make it strong enough to withstand the required one kilogram load.
Fig 11 – Cantilever Bridge, showing tension/compression points.
Fig 12 – Inertia example.
Fig 13 – Bridge Component Layout, showing main bracing & components needed.
8
CONCEPT AND INITIAL DESIGN IDEAS Nic - My design idea was inspired by buildings using a cantilever style, I did some research into these structures and was intrigued by the modular design and exposed truss designs.
Craig – My concepts looked at the potential of the cantilever and what could be achieved, with the constraints laid out on the brief. Also any possible ideas for the final model, the shapes or idea and the types of trusses that could be used. Fig 16
Fig 14
Callum – The initial idea I looked at was a standard ‘crane’ type cantilever, however upon discussion with the team, and after several meeting discussing designs, we resulted on a modular concept, which can be seen in the final drawing. A combination of this idea and other designs, and further cantilever and truss research, resulted in the final outcome of our project.
Fig 18
Fig 17
Fig 15
Fig 17
Musawar - My concepts mainly look at how we could stabilise the base so I looked into tension cables, counter balances and how we could keep the crane like structure stable.
9
MODEL DEVELOPMENT 1
Fig 19
Fig 20
Figs 19-23
Figs 27-28
Here we tried, tested and adapted ideas on that we had for trussbracing with spaghetti pieces.
Finally after looking into triangular forms and possible ways of bracing the concept idea.
1. Vierrendeel Truss -with & without diagonal Bracing (Fig 20 & 21) 2. Warren Truss, (Fig 22) All parts of the structure framework, were built up in a “modular form” concept before connecting together to test our idea and see if it would fit together and work. (Fig 23)
Fig 24
Fig 25
Fig 26
Fig 21
We proceeded to construct our initial idea into a 1:10 scale replica of our final design.
Fig 27
Here we used single 3mm dowels to test where any weak points or what would be the best method of joining them all together would be. At this stage, UHU glue would suffice and allowed the structure to remain stable and strong enough to hold an imposed load at the end of the cantilever.
Fig 28
Once after the concept model was created, we moved onto initial final model design and construction.
Figs 24-26 The next stage of development, was constructing our structure with dowel bars. Here we noticed that we would potentially have to change to a triangular form to compensate on materials being used. Fig 22
Fig 23
10
MODEL DEVELOPMENT 2 Figs 29-34 Moving onto the construction side of the model making.
Fig 29
Fig 30
We firstly created a materials list (Fig 34) for all the members of dowel bars we had at our disposal. Taking into account the lengths and quantities needed, considering also the need for bracing/support members; as well as a 10% wastage factor. Fig 29-32 show how we attempted to create better joints and bracing, where it came to the structural node points.
Fig 35
Fig 33 shows a finished example of one piece of our “Modular Components” before we started to piece together our model, this was our Cantilever section. On the cantilever shown, we took special care in creating a “Pratt Truss” running along the length. Fig 31
Fig 32
Fig 36
Figs 35 & 36 Two finished examples our final design idea. Fig 35 shows the model at completion in the workshops. Fig 34 Fig 33
Figure 36 is after model testing on 13/11/17 thankfully still in one piece after having the designated load added onto it.
11
MODEL DEVELOPMENT 3 Whilst using the 3mm dowel bars, we looked into possible ways of connecting them together, as you would with normal timber pieces. Rather than just relying on glue and using string, to keep the structure in place and together.
Fig 37 – Butt Joint
Majority of the joinery techniques that we used were simple “Butt Joints” (Fig 37) before we started to realise how unstable each joint would become. Hence we looked into other types. Such as the Corner halving and Tongue & Groove methods. (Figure 38 & 39) Both would of provided better stability to the structure, but would be inevitably more time consuming for every joint. If we were to individually cut each strut, brace, beam and length of the timber dowel bars.
Fig 38 – Corner Halving
Fig 39 – Tongue & Groove
Fig 41 – Finished Example of Corner Halving
Fig 41a
However for simplicity of the overall project, we kept to either Butt joints & Corner halving.
Fig 40 The idea of locking the “dowel-bars” into each other, to help create a more solid framework. With Glue or lashed together with cordage was considered during the design phase.
Fig 42 – Practice Attempt at Tongue & Groove joint
12
DESIGN DEVELOPMENT
Once we came to our final design, shown in figure 43, we collaboratively came together in order to develop this idea, exploring ways in which we could further the structural integrity of the product in order to withstand the 1KG bag of sugar with ease. The first thing we looked at was the weak points of the product, and which sections would require the most attention when designing the model. We created a scale model of the product on a 1:5 scale (See figure 45 & 47), which we later tested to help us identify these areas. The main focus points we gathered was the areas where the legs attach to the base, and the cross section of the stem and the base. (See Fig 45) The leg and the cantilever shape we initially changed in order to save materials for other parts of the model, such as truss and bracing further down the line.
Fig 43
In order to strengthen: • The legs: - Focus on Truss along the legs - How the legs physically attached to the base.
Fig 44
In order to make the main shape of the model more sturdy and stop from warping or bending under weight, in places we doubled and tripled the dowel, as we felt that this would counter the problems stated, and provide more structure. This can be seen in Figure 46, taken of the base of the model, during the making process.
• The stem attachment to the base: - The stem was extended down into the base to create a cross section. - Truss and bracing along the stem and base. - Angled bracing from the side edge of the base, to the top of the stem, in order to stop twisting when a weight was added. (See fig 48) Fig 45
We wanted to keep the modular look of the product, as we felt like this separated us from other groups who may have followed a standard crane type cantilever.
Fig 46
Fig 47
Fig 48
13
MODEL REVIEW Positive Aspects: During the testing phase, when we placed our model into the designated 600x600mm base layout. There was no timber-members of the structure outside of this constraint. Which looking back on some other groups (during the test phase). This was not taken into consideration, during there design phase. When we tested the model with a one Kilogram load, the overall structure successfully held, with no breakages or failings in the joints. We especially took notice at all node-points where we thought there would be potential structural weakness. These areas did not break however and there was no stress or strain signs shown on the model upon closer inspection (Wood splintering or snapping). Which proved to our group, that our understanding of weight distribution and bracing did work for the imposed loading along the conjoining cantilever and its connection to the mast. Negative Aspects: However, where the model failed; was when the load was imposed onto our cantilever beam. Even though it held as mentioned, the load imbalanced the overall model and because of no counterbalance being imposed at the rear (Either at the base of the structure or at the end of cantilever) forced the structure to topple over. What we learnt from this testing was that this problem was found universally throughout all the groups. The imposed loading needed to be more supported with a counter weight. With this aspect, we should of looked into more detail into how to create a counter balance at the rear of our structure and for future work and reference, we will develop in more detail. Fig 49
14
OTHER GROUPS EVALUATION – GOOD EXAMPLE This is an example of a structure that we felt worked well, in this picture we can see that the base was very wide and the spine of the structure was securely glued and wrapped with string around the base so that the spine wouldn't move. We can also see that the cantilever was securely placed between a few dowels so that it would have no chance of moving or breaking, they’ve also created tension along the top so if some of the bracing failed the rope would help keep it from falling and breaking. However the structure was way too wide and because of that it was considered cheating. However it was a structure which had a good base with a strong spine and a cantilever which didn't move even when the 1kg weight was applied on the cantilever. Overall the structure was good it worked well and did hold the weight but the structure was way too wide and didn't meet the requirements.
Fig 50
15
OTHER GROUPS EVALUATION – BAD EXAMPLE This is an example of a structure that didn't work in the final test, there were a lot of things wrong with this structure for example the base was too thin and it didn't have a wide base to support the load that would’ve been placed on the cantilever. In addition to this, the spine of the structure was too skinny to stabilise the structure so the end result was that the structure fell over when the 1kg weight was applied to the end of the cantilever. What was also noted was when the weight was applied, the spine of the structure twisted, this meant that the spine of the structure wasn't braced thoroughly. To improve the structures performance they could’ve, broadened the base so it had a steady platform, braced the spine of the structure a little more to make it stronger, using more dowels to support the spine and when placing the cantilever they should’ve placed it between a few dowels so it was secure. We feel this would’ve made it look a little better aesthetically and would have kept the cantilever in place.
Fig 51
16
OTHER GROUPS EVALUATION – AESTHETIC EXAMPLE This is a picture of the most aesthetically pleasing structure to us, this worked well and it held the 1kg weight, it also looked smart as they didn't have any lose string except for the hook in the front which was where they would have hung the weight. The strings for the joints were tied up very neatly and the gluing was very good as you could hardly see any excess glue, they used paper to cover up large holes and cut the paper out exactly to size so there wasn't any excess on the structure. The tension ropes looks neat and in general the structure looked, original and in the end the structure did hold the 1kg weight. However there structure cut into the 400mm gap which was needed between the cantilever and the base including the legs of the structure this meant that they also went outside the brief. If they re-enforced the legs with the dowels that cut into the 400mm gap, we feel it would have worked just as well.
Fig 52
17
TECHNICAL DRAWINGS (GROUP I) See below technical drawings for our finished design model, at a 1:10 scale. • • • • • •
Right side elevation Left side elevation Front Elevation Rear Elevation Plan Isometric detail.
18
BIBLIOGRAPHY Fig 01 - Hualapai Tribe in Peach Springs, AZ. (2016). Skywalk at Eagle Point.Available: https://www.grandcanyonwest.com/skywalk--eagle-point.htm. Last accessed 13th Nov 2017. Fig 02 – http://www.nbcnews.com, 2006. Get a Bird’s-eye view of the Grand Canyon. [Online] Available at: http://www.nbcnews.com/id/16191779/ns/travel-destination_travel/t/get-birds-eye-viewgrand-canyon/#.WgrP5Wi0PIU. [Date Accessed: 14/11/2017] Fig 03. Lift Architects. (2007). CANTILEVERED TABLE . Available: http://www.liftarchitects.com/blog/2007/2/12/cantilevered-table. Last accessed 13th Nov 2017.(Balance) Fig 04: AARON BERMAN. (2012). SUBURBIA TOWER. Available: http://www.aaron-berman.com/SUBURBIA-TOWER. Last Accessed: 14/11/2017 Fig 05: Visit Scotland. (2017). Forth Bridges. Available: https://www.visitscotland.com/info/towns-villages/forth-bridges-p243711. Last accessed 13th Nov 2017. Fig 06 - Network Rail. (2017). The history of the Forth Bridge, Fife. Available: https://www.networkrail.co.uk/who-we-are/our-history/iconic-infrastructure/the-history-of-the-forth-bridge. Last accessed 13th Nov 2017. Fig 07 & 08 - Will Coldwell. (Wednesday 2 August 2017). World’s longest pedestrian suspension bridge opens in the Swiss Alps. Available: https://www.theguardian.com/travel/2017/aug/02/worldslongest-pedestrian-suspension-bridge-swiss-alps-charles-kuonen. Last accessed 13th Nov 2017. Fig 09 - Structural Engineers Pocket Book- Structural form, stability & robustness (pg 26) – Cobb Fig 10 - Architects Pocket Book- Bending Moments &Beam Formula (pg 100) – Baden Powell Fig 11 - Encyclopedia Britannica . (2012). A cantilever bridge, with forces of tension represented by red lines and forces of compression . Available: https://www.pinterest.co.uk/pin/600456562789329870/. Last accessed 13th Nov 2017. Fig 12 – Inertia Example Nicohlas Onions Sketch Book, 2017. Fig 13 - Troydrew. (2012). Parts of a Truss Bridge. Available: https://www.google.co.uk/search?q=tension+and+compression&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiStLxv7vXAhUQqaQKHT8OBs0Q_AUICigB&biw=1306&bih=594#imgdii=7fdoXVc2Q9uQRM:&imgrc=EBV3Nob_Bynn9M:. Last accessed 13th Nov 2017. Fig 14 – Nicohlas Onions Sketch Book, 2017. Fig 15 – Callum Draffan Sketch Book, 2017. Fig 16 – Craig Gregory Sketch Book, 2017. Fig 17 – Musawar Jalil Sketch Book, 2017. Fig 18 – Callum Draffan Sketch Book, 2017. Figs 19 - 36 - Combined Photographs taken over the entirety of the project (2017) Fig 37 & 38 - DIY Data. (2012-2017). Timber Joints - Frame . Available: https://www.diydata.com/techniques/timber_joints/frame_joints/frame_joints.php. Last accessed 13th Nov 2017. Fig 39 - Alex Rice. (2016). Types of Timber Joints Used in Woodworking.Available: https://toproutertables.com/timber-joint-types/. Last accessed 13th Nov 2017. Figs 40 - 52 - Combined Photographs taken over the entirety of the project (2017)
19