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Type of Space Frame structure

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1. The space frame structure is divided into double-layer space frame and multi-layer (three-layer) space frame according to the number of layers. 2. The double-layer space frame is composed of the upper mystical layer, the abdominal poles, and the lower mystical layer. 3. The three-layer space frame is composed of upper, middle, lower, upper and lower abdomen layers. – PowerPoint PPT presentation

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Title: Type of Space Frame structure


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Type of Space Frame structure
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  • The Three Gorges Project is a magnificent project
    spanning the century. Its warehouse has a total
    length of 642.7m and a width of 39.0m. There are
    two 1200T bridge cranes and two 125T small bridge
    cranes in the workshop. The roof load is
    relatively large. The roof adopts a square cone
    welded ball space frame. The frame structure and
    the space frame structure are supported on the
    upstream and downstream wall structures. The
    space frame structure participates in the overall
    function of the warehouse structure, and the load
    combination is very complicated.

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? . The form and selection of space frame
  • 1. The characteristics of the space frame
  • 2. The form of the space frame structure
  • 3. Selection of space frame structure

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1. The characteristics of the space frame
  • The space frame structure is a spatial dumpling
    connecting rod structure, which is a spatial
    high-order statically indeterminate structure
    system with good mechanical performance.
  • advantage
  • Space structure, less steel consumption,
    economical
  • Wide application range and strong
    adaptability
  • The overall rigidity is large, the stability
    is good, the shock resistance is good, and the
    safety reserve is high
  • Flexible shape, convenient layout, beautiful
    and lightweight
  • Industrial production

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2. The form of the space frame structure
  • 1. The space frame structure is divided into
    double-layer space frame and multi-layer
    (three-layer) space frame according to the number
    of layers.
  • 2. The double-layer space frame is composed of
    the upper mystical layer, the abdominal poles,
    and the lower mystical layer.
  • 3. The three-layer space frame is composed of
    upper, middle, lower, upper and lower abdomen
    layers.

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Double-layer space frame form
  • 1. Plane quilting system 1 Two-way orthogonal
    placement 2. Two-way orthogonal oblique placement
    3. Two-way oblique intersecting oblique placement
    4. Three-way space frame
  • 2. Quadrangular pyramid system 1. Positive
    quadrangular pyramid system 2. Positive discharge
    quadrangular pyramid system 3. Unidirectional
    polyline space frame 4. Oblique quadrangular
    pyramid system 5. Checkerboard quadrangular
    pyramid space frame 6. Star quadrangular pyramid
  • 3. Triangular cone system 1. Triangular cone
    space frame
  • 2. Evacuate triangular cone space frame 3.
    Honeycomb triangular cone space frame

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(1), two-way orthogonal positive-laying space
frame
  • The two-direction orthogonal right-laying is
    formed by the vertical crossing of two-direction
    plane trusses. When applied in a rectangular
    building plan, the two-way quilting is
    perpendicular to the boundary (parallel)
  • The number of space frame in the two
    directions should be arranged in an even number.
    If it is an odd number, the internodes in the
    middle of the quilt should be made into cross
    webs.
  • Because the space frame composed of the
    upper and lower chords of the space frame is
    rectangular, the webs are in the plane of the
    upper and lower chords, which is geometrically
    variable.

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  • The force of the two-way orthogonal
    orthographic space frame is similar to the
    two-way equal-rigidity cross beam, which varies
    with the plane size and supporting conditions.
    For peripheral support, the closer the plane size
    is to the square, the closer the internal forces
    of the quilting rods in the two directions, and
    the more significant the spatial effect. But with
    the increase of the side length ratio, the
    one-way force transmission effect increases
    obviously. For the point-supported space frame,
    the internal force of the rod near the support
    and the rod of the main quilt is larger, and the
    internal force of the rods in other parts is
    small, and the difference between the two is
    large.

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  • Two-way Orthogonal Space Frame

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(2) Two-way orthogonal diagonally placed space
frame
  • The two-way orthogonal diagonal space frame is
    formed by the vertical cross of the two-way flat
    quilting frame. When applied in the rectangular
    building plan, the angle between the two-way
    frame and the boundary is 45 degrees. It can be
    understood as a two-way orthogonal orthographic
    space frame that rotates at an angle of 45
    degrees when it is placed on the building plane.
    The span of the two directions of the two-way
    orthogonal diagonal space frame frame is
    different, the number of nodes is more or less,
    and the short bracket near the corner is more
    rigid, and it supports the long quilt
    perpendicular to it. Reducing the force on the
    mid-span chord of the long quilted frame is
    beneficial to the force on the space frame frame.

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Two-way orthogonal diagonally placed space frame
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Two synchro diagonally placed space frame
Three-way space frame
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(4) Three-way space frame
  • The three-way space frame is composed of three
    quilting frames intersecting each other at an
    angle of 60 degrees. The space frames of the
    upper and lower chord planes of this type of
    space frame are regular triangles, which are
    geometrically invariant, with large spatial
    rigidity, good force performance, and the support
    force is relatively uniform, but the members that
    meet at a node can reach as many as 13 The root
    and node structure is more complicated, and
    welded hollow sphere nodes should be used.
    Three-way space frames are suitable for larger
    spans (greater than 60 meters), and the building
    planes are triangles, hexagons, polygons and
    circles. When used for circular planes, some
    non-triangular space frames will appear around
    them.

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(5), forward quadrangular pyramid system
Basic unit of quadrangular pyramid system
Square pyramid space frame
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  • The quadrangular pyramid space frame frame is
    composed of inverted quadrangular pyramids, the
    four sides of the cone bottom are the upper
    chords of the space frame, the cone edges are the
    webs, and the tops of the cones are connected to
    form the lower chord. When the building plane is
    rectangular, the upper and lower chords are
    parallel (perpendicular) to the boundary. The
    upper and lower nodes are respectively connected
    with 8 rods, and the node structure is relatively
    uniform. If the dimensions of the two directions
    of the space frame are equal, the angle between
    the web rod and the lower chord plane is 45
    degrees, h0.7s (h is the height of the space
    frame, s is the space frame size), and the
    lengths of the upper and lower chords and the web
    rod are equal, so that the rod Piece
    standardization. The space rigidity of the square
    pyramid space frame frame is larger than that of
    other types of square pyramid space frame frame
    and two-way space frame frame, and the amount of
    steel used may be slightly higher. This kind of
    space frame is widely used at home and abroad due
    to standardization of rods and unified nodes,
    which is convenient for factory production.

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(6), the quadrangular pyramid space frame is
being discharged and evacuated
  • The positive discharge and evacuated quadrangular
    pyramid space frame is based on the positive
    quadrangular pyramid space frame, and some of the
    web and lower chords in the quadrangular pyramid
    units are appropriately removed, so that the
    space frame size of the bottom chord is twice as
    large as the space frame size of the top chord.
  • The number of rods of this kind of space frame is
    small, the total number of web rods is about 3/4
    of the total number of the web rods of the
    quadrangular pyramid space frame frame, and the
    lower chord is reduced by about 1/2, so the
    structure is simple and the economic effect is
    better.
  • As the surrounding space frames are not suitable
    for drawing rods, the number of space frames in
    the two directions should be odd. If h0.7s, the
    lengths of the upper and lower chords and webs
    are equal. The force of this kind of space frame
    is similar to that of the orthogonal cross beam
    system, and the stiffness is weaker than that of
    a quadrangular pyramid.

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Positively placed quadrangular cone evacuated
space frame
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(7), one-way broken line space frame
  • The one-way broken-line space frame is a space
    frame made up of a quadrangular pyramid space
    frame without the vertical upper and lower
    chords, and a circle of longitudinal upper chords
    is reserved around it, which is suitable for
    peripheral support.
  • The quadrangular pyramid space frame is placed in
    the front, and it is used when the aspect ratio
    is greater than 3 in the case of peripheral
    support. The unidirectional broken-line space
    frame is in a state of unidirectional force, and
    the force is transmitted by a V-shaped truss. It
    is more rigid than a simple plane truss, and no
    support system is required. All members are
    stressed members. .

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One-way polyline space frame
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(8). Place the quadrangular pyramid space frame
diagonally
  • The diagonally placed quadrangular pyramid space
    frame is also composed of inverted quadrangular
    pyramids. The upper chord space frame is placed
    orthogonally, and the bottom chord space frame is
    placed orthogonally that is, the bottom chord is
    perpendicular (or parallel) to the boundary, and
    the top chord is at 45 degrees to the boundary.
    Angle. The length of the upper chord of this kind
    of space frame is equal to 0.7 times the length
    of the lower chord. In the case of peripheral
    support, the upper chord is compressed and the
    lower chord is tensioned. The space frame
    reflects the tension of the long rod and the
    compression of the short rod, so the force of the
    rods is reasonable. In addition, there are
    relatively few members that meet at the nodes (6
    upper chord nodes and 8 lower chord nodes). When
    the height of the space frame is half the length
    of the lower chord, the upper chord and the
    diagonal web are the same length. This kind of
    space frame is suitable for surrounding support,
    with simple node structure, reasonable force on
    rods, and less steel consumption. It is also a
    form that is widely used in domestic engineering.

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Inclined quadrangular pyramid space frame
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(9). Checkerboard-shaped quadrangular pyramid
space frame
  • The checkerboard-shaped quadrangular pyramid
    space frame is named because its shape is similar
    to that of a chess board. On the basis of the
    quadrangular pyramid, except for the surrounding
    quadrangular pyramid, the middle quadrangular
    pyramid is emptied, the lower chord is placed
    orthogonally, the upper chord is orthogonally
    placed, and the lower chord is at an angle of 45
    degrees with the boundary, and the upper chord is
    placed at an angle of 45 degrees. The rod is
    perpendicular (or parallel) to the boundary. It
    can also be understood as the diagonally placed
    quadrangular pyramid net frame rotated 45 degrees
    around the vertical axis. This kind of space
    frame also has the advantages of short upper
    chord and lower chord length, and there are few
    intersecting rods on the nodes, and the roof
    panel has a single specification, which is
    suitable for peripheral support.

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Checkerboard-shaped quadrangular pyramid space
frame
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(10). Star-shaped quadrangular pyramid space frame
  • The star-shaped quadrangular pyramid space frame
    is made up of two inverted triangular small
    trusses crossing each other. The bottom side of
    the two small quilts constitute the upper chord
    of the space frame, the upper chord is placed
    orthogonally and diagonally, the vertices of each
    unit are connected to form the bottom chord, and
    the bottom chord is placed orthogonally. The
    upper chords are in the same plane.
  • This kind of space frame also has the
    characteristics of short upper chord and lower
    chord length, and the force of the rods is
    reasonable. When the height of the space frame is
    equal to the length of the upper chord, the upper
    chord is the same length as the vertical rod, and
    the oblique web is the same length as the lower
    chord. This kind of space frame is suitable for
    peripheral support.

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Star-shaped quadrangular pyramid space frame
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(11). Triangular cone space frame
  • The triangular pyramid system space frame is
    composed of inverted triangular pyramids. The
    basic unit is a triangular cone.
  • The triangular pyramid space frame is composed of
    inverted triangular pyramids. Both the upper and
    lower chord planes are equilateral triangle
    meshes. The vertex of the lower chord triangle is
    on the centroid projection line of the upper
    mystic triangle mesh. The force of the triangular
    space frame is uniform. If the height of the
    space frame is 2/3 ½ times the space frame
    size, the upper and lower chords and web members
    of the space frame are of equal length. The
    number of intersecting rods at the upper and
    lower chord nodes are both 9, and the node
    structure types are uniform. Triangular cone
    space frame is generally suitable for large and
    medium-span buildings and heavy roof buildings.
    It is most suitable when the building plan is
    triangular, hexagonal or circular.

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Triangular cone space frame
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(12). Evacuate the triangular cone space frame
  • The evacuated triangular pyramid space frame is
    based on the triangular pyramid space frame, and
    some of the webs and lower chords in the
    triangular cones are appropriately removed, so
    that the upper chord mesh is still triangles, and
    the lower chord mesh is a combination of
    triangles and hexagons or all six. For the
    combination of polygonal shapes, the rule of
    taper tapping in the former is none of the space
    frames along the periphery of the space frame
    will taper, and the inside will be separated from
    the second circle along three directions to
    extract a triangular cone. There is a hatched
    part in the figure. To remove the mesh of the
    cone. The latter starts from the surrounding
    space frame, and draws one at two intervals along
    three directions. The hatched part in the figure
    is the space frame with the cone removed. The
    evacuated triangular pyramid space frame has many
    rods removed, and the overall rigidity is not as
    good as the dipyramidal space frame. It is
    suitable for small and medium-span triangular,
    hexagonal and circular building planes.

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Evacuate the triangular cone space frame
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(13). Honeycomb space frame
  • The honeycomb triangular pyramid space frame is
    composed of inverted triangular pyramids arranged
    according to a certain rule. The upper chord
    space frame is triangular and hexagonal, and the
    lower chord space frame is hexagonal. The upper
    chord of this kind of space frame is shorter, the
    lower chord is longer, and the force is
    reasonable. Each node only converges with 6 rods,
    the node structure is unified, and the amount of
    steel used is less. The honeycomb triangular
    pyramid space frame frame itself is geometrically
    variable. It needs to rely on the horizontal
    restraint of the support to ensure that its
    geometry remains unchanged. Attention should be
    paid to the construction and installation. The
    analysis shows that the internal forces of the
    lower chord and web members and the vertical
    reaction force of the support can be obtained
    from the static balance condition, and the
    internal force of the upper chord is determined
    according to the horizontal restraint of the
    support. This kind of space frame is suitable for
    surrounding small and medium span roofs.

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Honeycomb space frame
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