Tensile Structures Construction Details Pdf
Total Page:16
File Type:pdf, Size:1020Kb
Tensile structures construction details pdf Continue This article contains a list of general references, but it remains largely unverified because it does not have enough relevant link. Please help improve this article by entering more accurate quotes. (September 2011) (Learn how and when to remove this template message) The world's first tent steel shell by Vladimir Shukhov (during construction), Nizhny Novgorod, 1895 The Sidney Myer Music Bowl at Kings Domain, Melbourne A tensile structure - is the design of elements that carry only voltage and no compression or bend. The term tensile should not be confused with tensegrity, which is a structural form with both voltage and compression elements. Tense structures are the most common type of thin shell structures. Most tense structures are supported by some form of compression or bending of elements such as masts (as in O2, formerly the Millennium Dome), compression of rings or beams. The structure of the strained membrane is most often used as a roof, as they can economically and attractively cover long distances. Tensile membrane designs can also be used as complete buildings, with a few common applications of sports facilities, warehouse and warehouse buildings, and exhibition sites. The history of this form of construction has only become more thoroughly analyzed and widespread in large structures in the second half of the twentieth century. Tense structures have long been used in tents, where the guy's ropes and tent poles provide pre-voltage fabric and allow it to withstand loads. Russian engineer Vladimir Shukhov was one of the first to develop practical calculations of stresses and deformations of tense structures, shells and membranes. Shukhov designed for the Nizhny Novgorod Fair in 1896 eight tense structures and thin-storage structures of the exhibition pavilion with an area of 27,000 square meters. The later large-scale use of the membrane strained structure is the Sidney Mayer Music Bowl, built in 1958. Antonio Gaudi used the concept in reverse to create a compression-only structure for the Church of Colony Guell. He created a three-month-old church model to calculate the forces of compression and experimental determination of the geometry of the column and vault. Olympiastadion in Munich makes extensive use of strenuous roofing structures. The concept was later championed by German architect and engineer Frey Otto, whose first use of the idea was in the construction of the West German Pavilion at Expo 67 in Montreal. Otto then used the idea of roofing the Olympic Stadium for the 1972 Summer Olympics in Munich. Beginning in the 1960s, tense structures were enhanced by designers and engineers such as Ove Arup, Buro Happold, Walter Birder, Inc., Frey Otto, Mahmoud Bodo Rush, Saarinen, Horst Berger, Matthew Nowitzki, Jarg Schleich, the duo of Nicholas Goldsmith and Todd Dalland in the Design and Engineering Studio and David Geiger. Sustained technological advances have increased the popularity of fabric designs. Low weight materials make building easier and cheaper than standard designs, especially when huge open spaces should be covered. Types of structure with significant voltage members Linear structures Suspended bridges Draped cable cables Cable beams or farm Cable Farms Direct stretched cables Three-dimensional structure Bicycle wheel (can be used as a roof in horizontal orientation) 3D cable farm Tensegrity structures Surface-strained structures Pre-membrane pneumatic stressed membrane Gridshell Fabric fabric structure of the cable and membrane structure of Russia, 1895 Membrane Materials Common Materials for structures of dual curved PTFE fabric coated with fiberglass and PVC coating polyester. These are woven materials with different strength in different directions. Warp fibers (those fibers that are originally the direct equivalent of the starting fibers on a loom) can carry a greater load than weight or fill fibers that are woven between warp fibers. Other structures use ETFE film, either as a single layer or in the form of a pillow (which can be overstated to provide good insulation properties or for aesthetic effect, as at the Allianz Arena in Munich). ETFE cushions can also be engraved with patterns in order to allow different levels of light through when inflated to different levels. In daylight, membrane transparency tissue offers soft scattered naturally illuminated spaces, while at night, artificial lighting can be used to create an ambient outer luminescence. Most often they are supported by a structural framework because they cannot extract their strength from the double curvature. A simple suspension bridge, which works entirely in the tension of cables, can be made of soft steel, high-strength steel (drawn carbon steel), stainless steel, polyester or aramid fibers. Structural cables are made from a series of small twisted strands or connected to each other to form a much larger cable. Steel cables are either a spiral thread, where circular rods are twisted together and glued with a polymer, or a blocked filament coil where individual interconnected steel threads form a cable (often with a spiral core of thread). The spiral thread is slightly weaker than the blocked thread of the coil. The steel spiral threads of the cables have a Yang module, E 150±10 kH/mm2 (or 150±10 GPa) and come in sizes from 3 to 90 mm in diameter. The spiral thread suffers from the construction of a stretch where the strands are compact when the cable is loaded. This is usually removed by pre-stretching the cable and cycling load up and down up to 45% of the ultimate strenuous load. The filament of the coil usually has a 160±10 KN/mm2 module and comes in sizes from To a diameter of 160 mm. The properties of individual strands of different materials are shown in the table below, where UTS is the ultimate strenuous strength, or breaking load: E (GPa) UTS (MPa) Strain at 5 0% utS Solid Steel Bar 210 400-800 0.24% Steel Thread 170 1550-1770 1% Wire Rope 112 1550-1770 1.5% Polyester fiber 7.5 910 6% Aramid fiber 112 2800 2.5% Structural forms Air structures are a form of tense structures where the shell tissue is maintained under air pressure only. Most fabric structures draw their strength from their double curved shape. By forcing the fabric to take on a double curvature, the fabric acquires enough rigidity to withstand the loads it exposes (e.g. wind and snow loads). In order to evoke an adequately doubly curved shape, it is most often necessary to claim or claim a fabric or its supporting structure. The form of search behavior structures that depend on the prestress to achieve its durability is non-linear, so anything other than a very simple cable, until the 1990s, was very difficult to develop. The most common way to design doubly curved fabric structures was to build large-scale models of finite buildings in order to understand their behavior and conduct exercises to find shapes. Such large-scale models often use stocking material or tights, or soap film, as they behave very similar to structural fabrics (they cannot carry a shear). Soap films have a single stress in all directions and require a closed border for formation. They naturally form a minimal surface , a shape with a minimum area and embodying minimal energy. However, they are very difficult to measure. For a large film its weight can seriously affect its shape. For a membrane with curvature in two directions, the basic equilibrium equation: w t 1 R 1 t 2 R 2 (display w'frac) t_{1} R_{2} t_{2} R_{1}: R1 and R2 are the main curvature radii for soap films or deformation directions and paddles for t1 and t2 tissues are tension in appropriate directions w curvature is the load on the square meter Lines of the main curvature have no twist and cross the lines of the main Geodesic or geodesic lines are usually the shortest lines between two points on the surface. These lines are commonly used to determine the cutting patterned stitch line. This is due to their relative directness once the planar fabrics have been created, resulting in lower tissue loss and closer alignment with the fabric weave. In a pre-emphasized but unloaded surface w No 0, so t 1 R 1 - t 2 R 2 (display)frac (t_{1} t_{2}) R_{1} R_{2} In soap film surface voltages are homogeneous in both directions, so R1 and R2. Now you can use powerful nonlineary numerical analysis (or analysis of end elements) for and the design of fabrics and cable designs. Programs should allow for large deviations. The final shape, or shape, structure of the tissue depends on: the shape, or pattern, the geometry of the supporting structure (e.g. masts, cables, ring, etc.) claims applied to the fabric or its supporting structure of the hyperbolic paraboloid It is important that the final form will not allow water rationing, as it can deform the membrane and lead to local failure or progression. Loading snow can be a serious problem for the membrane structure, since snow often won't flow out of the structure as the water will. For example, this in the past caused the (temporary) collapse of the Hubert H. Humphrey Metrodome, an air-inflated structure in Minneapolis, Minnesota. Some structures prone to prudential use heating to melt the snow that settles on them. The shape of the saddle there are many different doubly curved shapes, many of which have special mathematical properties. The most basic are doubly curved from the shape of the saddle, which can be a hyperbolic paraboloid (not all forms of saddle hyperbolic paraboloids). It is a double rudder surface and is often used both in the lung structures of the shell (see hyperboloid structures).