phere with the maximum number of triangles but not much than a defined threshold.
I scaled that mesh just to fit Rhino grid, but it is not mandatory. What is useful, is to scale not uniformly the mesh (Scale NU). It could be done after cellular modifier applied or before or before and after. The 3 options are possible in the script. If you don’t need them just put 1 in scale sliders.
Ellipsoid mesh is the populated with points, I put 2 independents populations to randomize a bit further. For each vertices of the mesh the closest distance from the populated points is calculated.
Here is an illustration in color of this distance.
This distance is then used to calculate a bump. If domain for bump is beginning with negatives values to 0, it carves the mesh. Instead it bumps/inflates it.
Some images to illustrate the difference with populating 100 points with one or two populations.
Here some images to illustrate the application of scale before carving or after.
Next phase apply noise. At the moment I don't find it good.…
d simulate the bending process of a flat stell sheet in order to get the same shape. This can be really interesting so we can evaluate the material beheaviour, the deformation on the cross section a
nd explore big deformations in mecanics analysis of materials.
I am not a mecanical engineer nor a civil engineer, I´m an Architect and my interest is the construcction method and extracting the necesary information to consider fabricating the project.
I´m having conceptual challengings on the methodology for this simulation, so I will post a small overview of what I`ve done.
1.- Understanding the Geometry.
This is a sclupture by the Venezuelan/Hungarian/German artist Zoltan Kunckel (KuZo).
The shape is achieved bending a pre water cut square sheet of stainless steel. After bended manually, the different lashes are pulled on the opposite direction. New curvatures are produced after all is deployed.
2.- Reproducing the Shape digitally.
Using Karamba I built a definition to reproduce the produced by physical stress. This model served to find deformations that occur when a set of loads are applied to a mesh. Following this process will allow us to find a coherent and more natural cross section so then we could re-shape simulating the bending process of a piece of ductile material.
3.- Discretizing curve
Reducing the model to its simplest element is a key aspect of finite nonlinear analysis. Once our shape is already defined we can divide its principal characteristic of its principal given curve.
At this point I have already found the desired curve.
I Think the better strategy to simulate bending the steel sheet into this shape, is rationalize the curve and divide it finding the tangents one of the curve that compose this sort of parabola. bur i don`t know how to parametrize that in GH.
Please. If someone have a better Idea about this process I`ll glad to read sugestions.
Tomás Mena
…
rrect, the heat balance of a zone is always 0 = Qcool/heat + Qinf + Qvent + Qtrans + Qinternalgains + Qsol. These parameters also correspond with the readEPresult element. However, if i sum up these values there is a slight deviation.
The deviation is greater during daytimes and in winter, suggesting it has something to do with the heating values.
Attached you'll find an image of the energy plus outputs that I use and the resulting -.CSV file that I constructed. In this you'll see that the balance does not add up.
Am i missing some energy flows?
Thanks for the help.
Hour[H]
Qbal{kWh]
Qint[kWh]
Qsol[kWh]
Qinf[kWh]
Qvent[kWh]
Qtrans[kWh]
Tair[°C]
Tdrybulb[°C]
DIFFERENCE
1
3,039357
0,137702
0
-0,253218
-0,321929
-2,000028
20
5,1
0,601884
2
3,107099
0,125462
0
-0,247457
-0,315484
-1,881276
20
4,6
0,788344
3
3,181073
0,119342
0
-0,261765
-0,334485
-2,473788
20
4,3
0,230377
…
are doing):
It's supposed to be an ARCHITECTURAL TAILGATING PAVILION,I had no idea what tailgating was at first,but apparently before the games(basketball,football...) or sometimes even during the games,people bring a canopy with themselves usually with a truck and start drinking,barbecuing,and watching the game under that!so as this semester's project,we want to design a pavilion instead of the ordinary cheesy canopy:D
The questions involved in the design of this tailgating pavilion are:
-it better have something with texas tech university but it's not really necessary!
-time management (installation and de-installation)
-having it into pieces that fit in the truck
-using new digital methods will be welcomed ( for example instead of having the typical television there,we can propose something like what zaha hadid did in the chanel pavilion,I guess she is projecting stuff on one of the wall panels(see the picture below))
-it should cover an area between 200-500 square-feet (20-50 sqm)(it's only for a few people(family and friends).
-the base surface that I provided in the rhino file is not what it will look like,I just made that to test the grasshopper definitions on it.so the shape of this tiny pavilion should try to devide the area into different zones to provide a scenario(oh they cook the food here,serve it there,and watch the game on the other side),so it could be a single volume or maybe a combination of different volumes ,Site placement design expressing content and messages rather than acting as a ‘container' or as the professor explained:
"It may comprise a single volume, or a number of smaller volumes, with internal spaces for few people gathering events and a possible dining - seating zone. Fifty per cent of the volume must be in the open air, not fully enclosed and be planned as to function also as an additional exhibition space as well as providing for a possible food outlet.
Capable of hosting small to medium-sized events and delivery of a retail, food and/or drink offer by sponsor partners.Mobility: designed to be erected in short time, plan to be used for one day only, and de installed by end of the day."
-at first I started with a voronoi shape on surface,but when I thought it through I saw that it's gonna be hard to assemble it when it comes to the physical fabrication,so I decided to use the triangles and try to kinda represent the voronoi pattern,not actually using it.
-the most important thing after coming up with the actual surface and volume for the pavilion is the joints.The material we should use is plastic!we can use the hot wirecutter to cut foam(that limits us to use a ruled surface for each of the modules),then we can either use the vacuum to get the shape and then use it to make molds(resin,glassfiber mold),actually I just got an email from our professor explaining that"Maximum table reach for a large modul is ~ 2050 mm or 1/2 of 13'-1/1/2" diameter. So a 8'x4' panel could be worked upon within the working space radius."
we can even use the foam as composite with the resin-fiberglass and not necessarily detach them.
I provided here some pdfs,for pavilions using plastic,the PE sheets seem interesting but I am not sure how to bend them exactly.(it is still considered using plastic,we dont have to necessarly use the instructions on how to use plastic that I explained above)(the first pdf provides good examples of plastic,and the second one has some example of joints"
-I am also wondering if I need to use any structure analysis plugins,to see if the shell will actually work and not fall apart in real life) ( I am not sure what plugins I can use for that since I am really new to grasshopper)
-also I am not sure what to do about the openings on the surface,I feel like maybe some of the modules shouldnt have openings(because of the sun,rain and also the dark needed in order to watch TV in the " TV area".and also for providing a more organic cool shape,and have differentiation in pattern like the first photo I provided in this discussion,which is also because those panel are smaller,and I tried to control the opening sizes with an attractor point so maybe later I can use the attractor points to control the opening sizes for the different zones"
I guess I never talked this much in my life,but I wanted to thoroughly explain what I nee to do,which was not bad for putting my thoughts together:D hehe:))
and as you can see I want to do alot with the small knowledge that I already have:(
hopefully I can make some modules with plastic,foam and/or resin composites showing the joints,and then maybe design a smaller area than the pavilion and make a tiny physical shelter,lol
…
ndard length elements without any cutting, and using only simple connections, such as cable ties or scaffold swivel couplers.
To summarize the approach I present here:
Design an initial shape
Remesh this form so that the edges are all roughly the length of the tubes we will use to build the structure
Rotate and extend the edges of this mesh to create the crossings
Apply a relaxation to optimize the positions of the tubes for tangency
demo_reciprocal_structures.gh
Initial form
In this example I show how to apply this system to a simple sphere. You can replace this with any arbitrary shape. It can be open or closed, and have any topology.
Remeshing
The new ReMesher component takes an input mesh, and a target edge length, and iteratively flips/splits/collapses edges in order to achieve a triangulated mesh of roughly equal edge lengths.
Press the Reset button to initialize, then hold down the F5 key on your keyboard to run several iterations until it has stabilized. (F5 just recomputes the solution, and this can be a quick alternative to using a timer)
Once the remeshing is complete, bake the result into Rhino and reference it into the next part of the definition (I recommend doing this rather than connecting it directly, so that you don't accidentally alter the mesh and recompute everything downstream later).
Alternatively you can create your mesh manually, or using other techniques.
Rotate and Extend
We generate the crossings using an approach similar to that described by Tomohiro Tachi for tensegrity structures here:
http://www.tsg.ne.jp/TT/cg/FreeformTensegrityTachiAAG2012.pdf
Using the 'Reciprocal' component found in the Kangaroo mesh tab, each edge is rotated about an axis through its midpoint and normal to the surface, then extended slightly so that they cross over.
By changing the angle you can change whether the fans are triangular or hexagonal, and clockwise or counter-clockwise.
Choose values for the angle and scaling so that the lines extend beyond where they cross, but not so far that they clash with the other edges.
Note that each rod has 4 crossings with its surrounding rods.
There are multiple possibilities for the over/under pattern at each 'fan', and which one is used affects the curvature:
A nice effect of creating the pre-optimization geometry by rotating and extending mesh edges in this way is that the correct over/under pattern for each fan gets generated automatically.
Optimization for tangency
We now have an approximate reciprocal structure, where the lines are the centrelines of our rods, but the distances between them where they cross vary, so we would not actually be able to easily connect the rods in this configuration.
To attach the rods to form a structure, we want them to be tangent to one another. A pair of cylinders is tangent if the shortest line between their centrelines is equal to the sum of their radii:
Achieving tangency between all crossed rods in the structure is a tricky problem - if we move any one pair of rods to be tangent, we usually break the tangency between other pairs, and because there are many closed loops, we cannot simply start with one and solve them in order.
Therefore we use a dynamic relaxation approach, where forces are used to solve all the tangency constraints simultaneously, and over a number of iterations it converges to a solution where they are all met. The latest Kangaroo includes a line-line force, which can be used to pull and push pairs of lines so that they are a certain distance apart. Each rod is treated as a rigid body, so forces applied along its length will cause it to move and rotate.
The reciprocal component uses Plankton to find the indices of which lines in the list cross, which are then fed into the force for Kangaroo. We also use springs to keep each line the same length.
If the input is good, when we run the relaxation (by double clicking Kangaroo and pressing play), the rods should move only a little. We can see whether tangency has been achieved by looking at the shortest distance between the centerlines of the crossing rods. When this is twice the rod radius, they are tangent. Wait for it to solve to the desired degree of accuracy (there's no need to wait for 1000ths of a millimeter), and then press pause on the Kangaroo controller and bake the result.
The radius you choose for the pipes, curvature of the form and length of the edges all affect the result, and at this stage you may need to tweak these input values to get a final result you are happy with. If you find the rods are not reaching a stable solution but are sliding completely off each other, you might want to try adding weak AnchorSprings to the endpoints of the lines, to keep them from drifting too far from their original positions.
For previewing the geometry during relaxation I have used the handy Mesh Pipe component from Mateusz Zwierzycki, as it is much faster than using actual surface pipes.
To actually build this, you then need to extract the distances along each rod at which the crossings occur, and whether it crosses over or under, mark the rods accordingly, and assemble (If there is interest I will also clean up and post the definition for extracting this information). While this technique doesn't require much equipment, it does need good coordination and numbering!
There is also a ReciprocalStructure user object component that can be found in the Kangaroo utilities tab, which attempts to apply steps 3 and 4 automatically. However, by using the full definition you have more control and possibility to troubleshoot if any part isn't working.
The approach described here was first tested and refined at the 2013 Salerno Structural Geometry workshop, lead by Gennaro Senatore and myself, where we built a small pavilion using this technique with PVC tubes and cable ties. Big thanks to all the participants!
Finally - this is all very experimental work, and there are still many unanswered questions, and a lot of scope for further development of such structures. I think in particular - which of the relative degrees of freedom between pairs of rods are constrained by the connection (sliding along their length, bending, and twisting) and how this affects the structural behaviour would be interesting to examine further.
Steps 3 and 4 of the approach presented above would also work with quad meshes, which would have different stability characteristics.
There is also the issue of deformation of the rods - as the procedure described here solves only the geometric question of how to make perfectly rigid straight cylinders tangent. The approach could potentially be extended to adjust for, or make use of the flexibility of the rods.
I hope this is useful to somebody. Please let me know if you do have a go at building something using this.
Any further discussion on these topics is welcome!
Further reading on reciprocal structures:
http://vbn.aau.dk/files/65339229/Three_dimensional_Reciprocal_Structures_Morphology_Concepts_Generative_Rules.pdf
http://www3.ntu.edu.sg/home/cwfu/papers/recipframe/
http://albertopugnale.wordpress.com/2013/04/05/form-finding-of-reciprocal-structures-with-grasshopper-and-galapagos/
…
value=WINTERDESIGNDAY, in SIZINGPERIOD:DESIGNDAY=SINGAPORE ANN HTG 99.6% CONDNS DB ************* IDF Context for following error/warning message: ************* Note -- lines truncated at 300 characters, if necessary... ************* 53 SizingPeriod:DesignDay, ************* indicated Name=SINGAPORE Ann Htg 99% Condns DB ************* Only last 10 lines before error line shown..... ************* 57 23.5, !- Humidity Indicating Conditions at Maximum Dry-Bulb ************* 58 101133., !- Barometric Pressure {Pa} ************* 59 2, !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15 mph) ************* 60 320, !- Wind Direction {Degrees; N=0, S=180} ************* 61 0.00, !- Clearness {0.0 to 1.1} ************* 62 0, !- Rain {0-no,1-yes} ************* 63 0, !- Snow on ground {0-no,1-yes} ************* 64 21, !- Day of Month ************* 65 12, !- Month ************* 66 WinterDesignDay,!- Day Type
The relevant lines in the IDF file is shown below:
SizingPeriod:DesignDay, SINGAPORE Ann Htg 99.6% Condns DB, !- Name 23, !- Maximum Dry-Bulb Temperature {C} 0.0, !- Daily Temp Range {C} 23, !- Humidity Indicating Conditions at Maximum Dry-Bulb 101133., !- Barometric Pressure {Pa} 2, !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15 mph) 320, !- Wind Direction {Degrees; N=0, S=180} 0.00, !- Clearness {0.0 to 1.1} 0, !- Rain {0-no,1-yes} 0, !- Snow on ground {0-no,1-yes} 21, !- Day of Month 12, !- Month WinterDesignDay,!- Day Type 0, !- Daylight Savings Time Indicator WetBulb; !- Humidity Indicating Type ! SINGAPORE_SGP Annual Heating 99%, MaxDB=23.5°C SizingPeriod:DesignDay, SINGAPORE Ann Htg 99% Condns DB, !- Name 23.5, !- Maximum Dry-Bulb Temperature {C} 0.0, !- Daily Temp Range {C} 23.5, !- Humidity Indicating Conditions at Maximum Dry-Bulb 101133., !- Barometric Pressure {Pa} 2, !- Wind Speed {m/s} design conditions vs. traditional 6.71 m/s (15 mph) 320, !- Wind Direction {Degrees; N=0, S=180} 0.00, !- Clearness {0.0 to 1.1} 0, !- Rain {0-no,1-yes} 0, !- Snow on ground {0-no,1-yes} 21, !- Day of Month 12, !- Month WinterDesignDay,!- Day Type 0, !- Daylight Savings Time Indicator WetBulb; !- Humidity Indicating Type
It seems that there is an empty line after the line for "!- Humidity Indicating Type" field, and nothing is specified for "! SINGAPORE_SGP Annual Heating 99%, MaxDB=23.5°C" field.
May I ask why this happens and how to correct the error?
Thank you very much!…