SPACE FRAMES AND GEODESIC DOMES SPACE FRAMES AND GEODESIC DOMES Objectives: 1. Students will be exposed to the concepts of point, line, plane and dimensions in relationship to the triangle. 2. Understand the basic structural engineering concepts that underlie geodesic dome construction; 3. Understand the advantages and disadvantages of modern building materials in dome construction; and 4. Have an increased awareness of more in-depth concepts relating to the study of architecture, geometry, and structures. WARM UP ACTIVITY • Select a team member that you will plan with to complete this project; • Write a four to six sentence Design Statement about how your team think the roof of large structures (stadiums, gymnasiums, concert halls, etc.) are built without columns. Include your definitions of a geodesic dome and a space frame. Vocabulary • A polyhedron (many surfaces) is a geometric solid in three dimensions with flat faces and straight edges. • A tetrahedron is a polyhedron with four sides, but is also called a pyramid. • A hexahedron is a polyhedron with six sides, but is also called a cube. • A polyhedron with six rectangles as sides also has many names—a rectangular parallelepided, rectangular prism, or box. • An octahedron is a polyhedron with eight faces. Vocabulary • Tension is a force that acts to expand or lengthen the thing it is acting on. • Compression is a force that acts to compress or shorten the thing it is acting on. • SPACE FRAME STRUCTURE SPACE FRAMES CAN SPAN LONG DISTANCES SPACE FRAMES • A space frame is a truss-like, lightweight rigid structure constructed from interlocking struts in a geometric pattern. SPACE FRAMES • Space frames usually utilize a multidirectional span, and are often used to accomplish long spans with few supports. SPACE FRAMES • They derive their strength from the inherent rigidity of the triangular frame; flexing loads (bending moments) are transmitted as tension and compression loads along the length of each strut. Simplified space frame roof with the half-octahedron highlighted in blue • Space frames are an increasingly common architectural technique especially for large roof spans in modernist commercial and industrial buildings Some space frame applications include: • Hotel/Hospital/commercial building entrances • Commercial building lobbies/atriums • Parking canopies Advantages of space frame systems over conventional systems: Random column placement Column-free spaces Minimal perimeter support Controlled load distribution Design freedom Supports all types of roofing GEODESIC DOMES • A geodesic dome is a sphere-like structure composed of a complex network of triangles. GEODESIC DOMES • Geodesic domes are usually hemispheres (parts of spheres, like half a ball) made up of triangles. The triangles have 3 parts: –the face - the part in the middle –the edge - the line between corners –the vertex - where the edges meet The triangles create a self-bracing framework that gives structural strength while using a minimum of material. DOMES A dome’s design is dependent upon many factors, including: • Needed area and span, or distance between supports; • Budget and building schedule; • Architect’s and /or client’s aesthetic preferences; • Forces, such as compression and tension, acting on the structure; and • Building materials. EXAMPLES OF GEODESIC DOMES: Spaceship Earth, the AT&T Pavilion at Epcot in Disney World, Florida, is an adaptation of Buckminster Fuller's geodesic dome Tacoma Dome in Washington State Milwaukee's Mitchell Park Conservatory Biosphere desert project in Arizona Des Moines Arboretum, a self contained ecosphere Engineering Disasters Engineers must be concerned about safety at all times. Lives are at stake when bridges, buildings, or structures collapse. Engineers must design structures to withstand all kinds of weather conditions and all types of loads. While the goal is to have no design fail, engineers examine and learn from past mistakes to avoid such failures in the future. • Tacoma Narrows Bridge, Tacoma, Washington (failed in 1940) 10 killed Engineering Disasters • Falls View Bridge, Niagara Falls (failed 1938) 18 killed • Tay Bridge, Scotland (failed in 1879) 29 killed • Quebec Bridge, St. Lawrence River (failed 1907,1916) 45 killed Engineering Disasters • Point Pleasant/Silver Bridge, Ohio River (failed 1967) 75 killed • Hyatt Regency Walkway Collapse, Kansas City, Missouri (failed in 1981) 112 killed TEAM CHALLENGE ASSIGNMENT The team challenge is to build a 3dimensional triangle; Team members must discuss the concept among themselves as they each attempt to build a model. 15 minutes… TEAM SYNTHESIS Team members must attempt to join their 3-dimensional triangles; Each link should be connected firmly and completely; Repeat the process until four triangles joined together in a square. 20 minutes… Rubric For Space Frame Project Layout/ Design Information Contributions Quality Of Work Following Classroom Guidelines Brief Constructed Response Student must complete a responding to one of the following topics: You are a hired Engineer designed to build a space frame for the new town. Your employers are not convinced that your space frame design would be successful. Create a BCR that explains how your space frame will withstand the forces placed on space frames: Compression, Tension, Shear, and Torsion. Brief Constructed Response Student must complete a responding to one of the following topics: You are a space frame inspector that has been hired to inspect space frames. Create a BCR that explains how “Live” and “Dead” loads would be handled in your space frame design. Use examples to illustrate how these loads would be supported. HOMEWORK 1. Research: Buckminster Fuller 2. Write about the accomplishments and contributions achieved by Buckminster Fuller and explain how they relate to today’s Architectural structures. One to Two Pages EVALUATION QUESTIONS FOR THE INDIVIDUAL GROUPS: 1. How did you come up with the initial design for your space frame? 2. Did your design change as you built your space frame? 3. Which geometric shapes did you use in your space frame? Why? 4. How does the strength of the space frame compare to the weight of the space frame? 5. Would you make any changes in the design of your space frame? EVALUATION QUESTIONS FOR THE WHOLE GROUP: 1. Which space frame was the longest? Tallest? Strongest? Heaviest? Why? 2. What materials do you envision being used in future space frames? 3. How can computers help design space frames? LET’S START BUILDING!!!!!