Timber Tectonics in the Digital Age

Transcription

1 Timber Tectonics in the Digital Age BAHAR ABIRI s PORTFOLIO PROFESSORS MARIAPAOLA RIGGIO AND NANCY YEN-WEN CHENG SPRING 2018

2 Columns & Beams Columns: Columns are classified by their length dimension between support ends. Application of short and long columns are different. Wood columns are supporting beams and girders, which in turn support roof and floor loads. Beams: A simply supported beam is substantially stronger and stiffer than a cantilever of the same length and same cross-sectional dimensions. Dendriform (tree-like) columns: In the tree like column, the individual element must be rigidly connected at the joints. It is suitable for only the one main load scheme. Columns can be produced with various shapes on elevation, which can be varied over the height in order to match the structural requirements. A doubly tapered shape can have less in the vicinity of the ends. By: Week 02 - handouts_columns-beams.pdf (By Dr. Riggio, Mariapaola) Arena_Stage.pdf The wood columns are spaced 36 feet apart and elliptically shaped for structural efficiency, to minimize their visual impact and create a feeling of transparency into and throughout the space. 2 2

3 Columns & Beams Beam and Column Modeling in Rhino: In this week I have learned how to design Beam and columns both theoretically and digitally. This experiment in trying to introduce Karamba, a plugin for Grasshopper. Karamba is a parametric structural engineering tool which provides accurate analysis of spatial trusses, frames and shells. I developed abilities in Rhino, Grasshopper and Karamba to modeling and creating columns and beams. For designing joint, Karamba assumes rigid nodes at connections between beams. And to creating curves, all beams need to be created from separate straight-line segments. All nodes must be exactly at the ends of beams for them to connect. 2 3

4 Frames & Trusses Frames: Frames are more efficient system than postand lintel system, because the rigid connection between the columns and the beam transfers the action on the columns to the beam, and through the beam to the opposite column. Trusses: Trusses are triangular frame works that members are essentially axial forces along of external load. They are used to span long lengths and referred to as lattice girders. The triangular subdivision of the planar system produces geometric units which make it stable. Stable framework consisting of elements connected only at their ends. Frame with some rectangular meshes In a truss, forces that are either tensile or compressive results from external loads, and the structure's reaction to those loads, act at the joints. The structure of Maggie Cancer Support Center, in Manchester is exposed throughout the building and consists of laminated veneer lumber (LVL) trusses each with a set of diagonally opposed double web elements. By: Week 03 -handouts_framesand trusses.pdf (By Dr. Riggio, Mariapaola) By: Trada_MaggieCentre Manchester.pdf 3 4

5 Frames & Trusses Truss ModelinginRhino: I tried to model this truss bridge on Rhinoceros with the module Grasshopper. The main aim is to design a parametric truss by this software. By changing the division of curve, changing the count, the truss can reinforce by increasing segments. In addition, by changing Y factor, the width of the truss changes. I think there is a direct relationship between these two factors. In other words, if we want to use this truss in a wide area, it needs to have more division in curve. So the more y factor needs more count on division of curve. Drawing truss through lunchbox 3 5

6 Arches & Domes Arch: The great property of an arch is to be able to transfer the load to the support only with compressive forces. They are mainly used in large structuresthat require a long span with no support. In addition, timberis commonly usedin buildingroofs, as it is light and easy to shape. One of the major problems of timber structure is the limited length imposed by natural dimensions. of trees. Glued Laminated Timber (Glulam) solve this issue. Glulam members can be fabricatedin long lengths and in almost any cross sectional shape. Domes: Modern timber domes are designed according to geodesic geometry. Week 04 -handouts_archesand domes.pdf (By Dr. Riggio, Mariapaola) Arch Geodesic domes are composed of triangles that are approximately equal, and such that the vertices of the triangles all lie on the surface of a sphere or a hemisphere. Geodesic dome structures do not need any additional bracing members because of geometry. Radialribdome Some examples of glulam arch connections 4 6

7 Arches & Domes Arch Model in Rhino: I tried to model this arch in Rhinoceros with the module On Grasshopper. The main aim was to have a parametric arch design. I tried to analyze this module by Karamba, a plugin in Grasshopper. I searched online, watching several tutorials to figure out how to calculate and optimize the algorithms on Karamba. 4 7

8 Grid, Shells, GridShells Grid: Rectangular beam grids are 2 identical beams at right angles which supported each other. In this shape, one beam placed in top of another one. The main difference between grid and diagrid from the form view is about angles which the beams do not intersect at right angles. Shell: 3D structure that carry loads through its shape. Normal and in-plane shear stresses are uniformlydistributedover the cross section. Timber lattice roof, is defined as a flat squared lattice that is lifted or lowered into a doubly curved shape. A lot of double curved timber structures consist of a lattice of ribs combined with one or more continuous layers of timber ply. This continuous layer provides interaction between the ribs and membrane action in a certain extend. Diagridshell Transport friendly setup. Assembly ready module Four modules connected. The grey ones are turned 90 related to the other two, creating a wowed pattern. The bypass-joints becomes the rule rather thanan exception from the rule. By: Week 05 - handouts_grid-shells-gridshells.pdf (By Dr. Riggio, Mariapaola) Expo Canopy, Hannover Germany, Herzog+partner, 2000 gridshell Trondheim_WCTE2016.pdf 5 8

9 Grid Shell Modeling in Rhino: I tried to model this grid in Rhinoceros with the module On Grasshopper. The main aim was to have a parametric arch design. I tried to analyze this module by Karamba, a plugin in Grasshopper. I looked at the Gridshellstructures-in-laminated-bamboo.pdf which Nancy sent to us. 5 9

10 Plated & Folded Plates Folded plates carry loads transversely to the ridge and valley of the plates. Each unit strip of slab acts transversely as a fixed-end beam. Each series of transverse strips of slab behaves like a continuous beam with equal spans, rigidly supported at the folds. The loads transferred transversely to the folds are then transferred in bending action along the length of the plate. Each slab acts longitudinally as a rectangular beam of width and depth. For plate systems, Cross Laminated Timber and plywood can be used. Nail laminated timber can be coupled with plywood sheets as top layer. Connections: Twisted dovetail joint helps assembling the structure. Also, a tongue and groove system can be used to lock each panel. Week 06 - handouts_plates and folded platess.pdf (By Dr. Riggio, Mariapaola) CAADFutures.pdf 7 10

11 Plates & Folded Plates FoldedPlates Modeling in Rhino: In this week we have learned how to design folded plates on Rhino using Grasshopper. At first, we learned basic modeling of folded plates. Then we have learned how to develop it and use Karamba to analyze and optimize the algorithm. Roof Folded Plates Basic Design Changing the Max Edge has influenced on the analyzes in Karamba. 4 11

12 By using the handouts and materials we learned at class: First, we worked modeling with gridshell. This model was the design we have in our group project. We are trying to figure out the form related to building structure and connections. Then we plan to use a grid that we raise from the ground and connect to form curvature. The structure is first made on the ground, which makes it relatively easy to assemble and connect together, then bent to the desired shape and fixed at its supports. It has bending moments within the members that experience axial compression and tension lo ads. It should be analyze this as a rigid system. 4 12

13 Then, for the midterm, we decided to make folded plates. We are still working on our system. Through the last week, we have learned about folded plates. We thought maybe by adding some beams make it stable. But, our folded plates still need some changes for having stable structure. These changes maybe can taken place by reinforcing by some beams, using tension cable or making a double layer of the form. With Karamba, we would analyze the structural capacity of the design and optimize the system. Using the top and bottom shell as a truss, and connecting shell plates can help to find the form with less deflections. 4 13

14 MY NAME: BAHAR ABIRI My address: List of Teammates: Ryan Maruyama Daniel Matallana Eli Metcalf Cody Knight Key documents consulted: Week 06 - handouts_plates and folded platess.pdf (By Dr. Riggio, Mariapaola) Week 05 - handouts_grid-shells-gridshells.pdf (By Dr. Riggio, Mariapaola) Week 04 -handouts_archesand domes.pdf (By Dr. Riggio, Mariapaola) Week 03 -handouts_framesand trusses.pdf (By Dr. Riggio, Mariapaola) Week 02 - handouts_columns-beams.pdf (By Dr. Riggio, Mariapaola) Arena_Stage.pdf By: Trada_MaggieCentre Manchester.pdf gridshell Trondheim_WCTE2016.pdf CAADFutures.pdf Master s Student BAHAR ABIRI S PORTFOLIO PROFESSORS MARIAPAOLA RIGGIO AND NANCY YEN-WEN CHENG SPRING 2018