Timber Tectonics in the Digital Age BLANKENBERGER, SCHUTZ, TAYLOR PROFESSORS MARIAPAOLA RIGGIO AND NANCY YEN-WEN CHENG | WINTER 2017 DOUGONG BRACKETING Denise Blankenberger | Antony Schutz | Molly Taylor
ARCH 510 TIMBER TECTONICS | Prof. Nancy Cheng [UO] Mariapaola Riggio [OSU] DESIGN 1: FRAMES + TRUSSES Dougong Bracketing
DESIGN
Our team agreed that we liked the aesthetic of the Japanese stacked beam systems and would like to reflect that in our first pass of the pavilion design. We thought that a combination of the stacked beams with thin cluster columns (that are braced around their midpoint) might make for an interesting pavilion that feels lightweight but is also structurally sound.
The canopy design was built to cover a 25’ square area. This is supported by a cluster of (4) 4”x4” columns and additional 4”x4” columns at the corners. All the connections can be hidden.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 1: FRAMES + TRUSSES Dougong Bracketing
DESIGN
In the scheme to the right, no optimization had occurred yet. Clearly, there are an excessive amount of members to support the structure. We assume that a better analysis of the system in Karamba, would prove that many of the intermediate beams can be removed with each growing stacked layer. It would take a bit of experimentation to understand when additional members are necessary or duplicative.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 1: FRAMES + TRUSSES Dougong Bracketing
CONNECTIONS
The structure is comprised of three main connections: 1. Ground to column 2. Column to first beams 3. First beams to secondary beams.
The column is composed of four elements each having its post base, the assembly between the ground and the column is stable. The configuration of the post base makes it possible to hide the screws.
The wood must have a ground clearance so as not to be damaged by rainwater when it bounces off the ground. If there is no ground clearance, the wood may rot due to water and fungi. In addition, as with water retention, wood may discolor. It is therefore necessary to provide a ground clearance of at least 20cm.
Simpson: https://www.strongtie.com
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 1: FRAMES + TRUSSES Dougong Bracketing
CONNECTIONS
It is important for this assembly that the components are hidden because it is one of the most visible parts, so we opted for an ETB Hidden Timber Connector. To make this assembly, it is necessary to machine the wooden elements to insert the connectors. The elements are hollowed out with a rooter. Although there is machining, this assembly has the advantage of removing very little material, which does not alter the mechanical strength of the structural element. In addition, the connectors are protected by wood. In the event of a fire, the fire cannot damage the assembly as long as there is wood. To ensure that the water does not stagnate in the assembly, a vertical discrete saw cut is required under the assembly. The connectors are fixed to the column and to the beam with screws.
Simpson: https://www.strongtie.com ETB Hidden Timber Connector (Simpson Strong-Tie Company Inc.)
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 1: FRAMES + TRUSSES Dougong Bracketing
CONNECTIONS
For this assembly, we chose stainless steel brackets. As they are placed on the top of the beams, they will not be visible from the ground. It is a cheap assembly and easy to implement.
The brackets are fixed to the first beam and to the secondary beam with screws.
Simpson: https://www.strongtie.com ETB Hidden Timber Connector (Simpson Strong-Tie Company Inc.)
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 1: FRAMES + TRUSSES Dougong Bracketing
DIGITAL FABRICATION
The series of operations are rather simple and are repeated with each layer (color coded in the model.)
The basic strategy of operations is move (z) -> scale -> rotate
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 1: FRAMES + TRUSSES Dougong Bracketing
DIGITAL FABRICATION / ANALYSIS
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 1: FRAMES + TRUSSES Dougong Bracketing
REFLECTION FEEDBACK
Although it would be quite simple to model our design in Rhino The commentary of our design was that it is indeed beautiful, but alone (and apply forces manually with Karamba), it was the secondary columns were unnecessary. It was also hoped that important to our team that we have a dynamic model so that we would be able to do more analysis in Karamba, but this was not we could get live feedback in regards to the design decisions possible given the need to move forward with subsequent we were making (i.e. how far to space the members, whether iterations and coursework with different structural systems. to include secondary columns, how many beams to include, etc).
We not only successfully modeled it in Grasshopper, but also were able to integrate it with Karamba. Further steps would mean using the Karamba analysis to investigate the structure in order to make design decisions on how much and where to brace our canopy/where to remove beams.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 GRIDSHELL PAVILION Denise Blankenberger | Antony Schutz | Molly Taylor
ARCH 510 TIMBER TECTONICS | Prof. Nancy Cheng [UO] Mariapaola Riggio [OSU] DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
INSPIRATION
This is the design inspiration for the pavilion – a design-build project actually completed in Lafayette, Louisiana by UL students.
The reason for using this project as our inspiration is the way the structure meets the ground. We agreed that we did not like the gridshell from the lecture that was hoisted on top of columns. Rather, we wanted to use the base support of the gridshell as a design feature – namely, a bench or seating place that people could enjoy. We also decided to use an arch as the second support feature in order to tie together the two weeks’ themes: arches (and domes) and gridshells.
University of Louisiana at Lafayette School of Architecture and Design: https://soad.louisiana.edu/news-events/news/20151209/lafayette-strong-p avilion-nearing-completion
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
DESIGN
With our goal in mind of creating a gridshell with a bench and arch for support, we began experimenting with catenary curves and shells in Grasshopper. We found that by offsetting one line (with the intended span in mind) and shortening one end, the proper head height clearance could be achieved.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
CONNECTIONS The structure is comprised of four main connections: 1. Ground to main arch 2. Main arch to secondary arches 3. Gridshell intersections to each other 4. Secondary arches to ground
1: The main arch is supported by a stainless steel post base. This post base is fixed to the floor with studs and to the main arch using stainless steel screws. 2: The secondary arches are connected to the main arch with notch and peg. Nevertheless, if the assembly is not enough strong, it is possible to make a pinned mortise-and-tenon joint or use steel connections.
Due to the difficulties of collaborating with such distances between group members, there are inconsistencies between the connections imagined by the designers and those specified by the construction expert. This was a learning experience. Simpson: https://www.strongtie.com BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
CONNECTIONS
3: This assembly is the most repeated of the structure since it connects all the arches between them. In order not to be over-demanded or to be a source of additional effort, it should not generate a moment. For this reason we have retained an articulated connection. The assembly is a halved joint with peg. However the machining must leave a little play to not block it. The bore of the peg must be narrow enough to wedge the peg. The best way to do this is to use a peg with a conical shape.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
CONNECTIONS
4: In order to maintain ground clearance, this assembly rests on a concrete low wall. The secondary arches are fixed using screws on a wooden support with a notch. The wooden support is fixed to the low wall with studs.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
CONNECTIONS / ENCLOSURE
For the enclosure of our pavilion, we look to the Lafayette Strong pavilion again for inspiration.
Our pavilion would also have bracket connections at the gridshell intersections that serve as the point where additional assembly pieces could be attached. We have entertained the idea of incorporating PV panels in association with some sort of fritted glass that keeps the interior of the pavilion shaded and protected from precipitation.
University of Louisiana at Lafayette School of Architecture and Design: https://soad.louisiana.edu/news-events/news/20151209/lafayette-strong-pavilion-nearin g-completion
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
DIGITAL MODEL
The first attempt at loading the gridshell and creating beams from the shell was largely unsuccessful. The primary form-finding exercises created the desired gridshell, but loading and supporting it was a challenge. Attempting first to use the Karamba “Find Similar” component caused for the selection of points not along the perimeter of the gridshell. Likewise, huge deformation errors resulted from attempting to support the “back bench” ground connection of the gridshell.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
DESIGN
The pavilion began to take shape when we reverted to loading points individually. As seen in the image to the right, the point loads at the main arch had to be given a higher load factor than the rest of the gridshell intersection points. The four corners of the gridshell were pinned as supports, as were the points where the “back” bench would be located.
(The supports are shown with green arrows.)
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
ANALYSIS
To the right, the form of the arch is finalized. It took some tweaking of the loads and material sizes, but ultimately, we are rather fond of the process and results created – using Karumba almost exclusively.
The materials are also sized with the assumption that a double-grid gridshell would need to be created for the assembly. This means essentially 4 layers of 2”x1” wood pieced together (see below right image.) The cross section input in Karamba simplifies these materials into 3”x3” members, though the assembly is a little more intricate than that.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 2: GRIDS + GRIDSHELLS Gridshell Pavilion
REFLECTION FEEDBACK
The Gridshell design was mostly based in form-finding. We Reviewers responded positively to the overall design and understand that our exploration of joints and fabrication appreciated our form as a response to the program (picnic shelter) tactics was minimal. With more time, we would have further with the appropriate openings and seating areas. Reviewers investigated different opportunities for interlocking the particularly liked the bench as the base detail for where the materials and enclosing the system. gridshell meets the ground.
However, the lack of consistency between the gridshell design and the connections was pointed out by reviewers. This inconsistency was due to miscommunications between remote team members during the design process.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 GIRIH TIMBER CANOPY Denise Blankenberger | Antony Schutz | Molly Taylor
ARCH 510 TIMBER TECTONICS | Prof. Nancy Cheng [UO] Mariapaola Riggio [OSU] DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy INSPIRATION
We saw the potential for geometric mosaics popular in Islamic art and architecture to translate well to a folded plate shell structure. In a time of global division, mistrust, and lack of understanding about Islam and its followers, this design seeks to promote cross-cultural dialogue and education while providing an attractive place to picnic and enjoy the outdoors. Our base pattern for the mosaic is similar to mosaic designs that utilize Girih tiles, which are the basic tile shapes that make up many Islamic geometric patterns.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy INSPIRATION
We were interested in using panel products for iteration 3. We originally experimented with folded plates and origami folds, but ultimately discovered that a shell would be the best structure to utilize the Girih patterns.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy DESIGN OPTIONS
As stated before, our preliminary efforts were to use origami-type folds in a folded plate design. We also looked into gridshells, using the hanging chain method. All of these experiments were created quickly in Grasshopper with Kangaroo and Karamba. We realized that the issue we kept running into was that we needed to construct a mesh using the boundary curves of the Girih pattern.
Molly discovered a method of doing just that: by first creating individual planar surfaces in Rhino, then inputting them into grasshopper and uniting them into one mesh, we could then input the geometry into the SmartForm plugin (similar to Kangaroo) to find a funicular form.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy DESIGN OPTIONS
After testing different variations with different conditions meeting the ground, our favorite design has four openings and is symmetrical for ease of modular construction.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy PLAN
This view makes it possible to see that some panels are designed to allow the light to pass and thus allow natural lighting.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy DESIGN
The pavilion would be an attractive place to move through, or to set up a picnic in the shade on a hot day.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy DESIGN
The following slides focus on the structural analysis of the folded plate structure, comparing analysis between a model with all plates intact, and a model with plates removed where the mosaic cut-outs occur.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy ANALYSIS: UTILIZATION
MAX UTILIZATION MAX UTILIZATION
The maximum utilization is located at the level of the The highest utilization is still located at the supports, supports, which is why the connections at these places however it is now just 11.5% with the steel supports, as must be sufficiently resistant to support the structure. opposed to 36.2% when the base was made of wood.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy ANALYSIS: DISPLACEMENT
The highest displacement with all panels present is With the panels removed, displacement was at first low--just -2.96 * 10^-9 inches, or -.00000000296 inches. higher, until we changed the supporting panels to steel. In this final iteration, displacement is even lower than the model with all panels intact. The highest displacement is -3.73 * 10^-10, or -.000000000373 inches.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy ANALYSIS: PRINCIPAL STRESS 1
1st Principal Stress shows us the maximum tensile stress With low-utilization panels removed and with steel in the structure. With all panels intact, the highest value supports, this stress is lower than the previous of stress is -3.12 ksi. iteration. It is now -.781 ksi.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy ANALYSIS: PRINCIPAL STRESS 2
2nd Principal Stress shows us the maximum compressive With low-utilization panels removed and steel stress in the structure. With all panels intact, the highest support triangles, the highest value for this stress value for this stress type is 12.4 ksi. type is 3.33 ksi, much lower than the previous iteration.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy ANALYSIS: VAN MISES STRESS
Van Mises stress shows the bending stresses in the With low-utilization panels removed and steel structure. With all panels intact, the highest value for this support triangles, the highest value for this stress stress type is 5.01 ksi. type is 1.1 ksi, lower than the previous iteration.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy FABRICATION
The pavilion is symmetrical and has four openings that touch the ground at a single point. This detail necessitated the design of a support condition that could both meet the ground and handle high stress levels at this point.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy x4 FABRICATION
In total there are 120 panels, but most are repeated shapes that can be divided into 4 bays. Each piece shown to the right is actually an individual unit with multiple layers (i.e. 2 sheets of plywood with hinges. See supporting pages for more details.)
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy FABRICATION
At right, a diagram showing the shapes and numbers of panels in the structure.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy FABRICATION
The pavilion will be constructed from laminated sheets of ¼” plywood to get to a full dimension of ½” thickness.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy FABRICATION
The joints of the pavilion are pivotal. Since we do not have access to robot that could mill the panel edges at the required angle, we chose to make the connections with steel hinges made of sheet metal sandwiched between two plywood panels. This connection is clean, simple, and allows light to penetrate through the edges between panels, highlighting the mosaic geometry.
The hinges are flexible enough that they enable some adjustment on-site, facilitating the construction of this complex geometry.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy FABRICATION
To temporarily support the pavilion as it is being assembled, milled pieces will be provided for the intersections between various pieces (of conditions where 3 or more corners meet). This will ensure that the angles are established correctly as the rigid hinges are attached.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy FABRICATION
The pavilion will be constructed on a concrete slab. In order to avoid contact between the wooden structure and the ground and to allow a higher resistance, the support connection consists of a steel triangle in the place of wood. This maintains the purity of the geometry. The steel triangle is fabricated with hinges on the edges to fasten it to the wooden structure. This connection is bolted to the concrete slab. .
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DESIGN 3: FOLDED PLATES + SHELLS
Girih Timber Canopy
REFLECTION FEEDBACK
Overall, this design was the most challenging – and most Reviewers loved the pattern design and appreciated the rigorous successful of the three designs. investigation in selecting a form, rather than choosing one form from the beginning. They agreed that our decision to make the triangles that meet the ground out of steel, rather than developing a bench detail or other base connection type. This was the best way to solve the issues of forces and keeping timber separate from the ground.
The primary criticism was that we did not really attempt to think about enclosing the structure. We did consider the issue of moisture wicking through the edges of the material of the panels, but we did not design a skin system for the design, particularly because it is a temporary structure. The point was also made that our renderings, which showed only the patterned cutout panels as casting shadows, were not consistent with our model, which had gaps between the panels through which light would penetrate. If we were to develop it further we would minimize those gaps between panels in our model.
BLANKENBERGER, SCHUTZ, TAYLOR TIMBER TECTONICS IN THE DIGITAL AGE - WINTER 2017 DENISE BLANKENBERGER [email protected]
MOLLY TAYLOR [email protected]
ANTONY SCHUTZ [email protected]
Credits
PROFESSORS MARIAPAOLA RIGGIO AND NANCY YEN-WEN CHENG | WINTER 2017