Tekla Structures – Bolts

washers, nuts, etc.).

Tekla Structures stores bolt assemblies in the bolt assembly catalog. The individual elements (bolts of different size and length, nuts, washers, etc.) are contained in the bolt catalog. For more information on catalogs, see Bolt and bolt assembly catalogs in the online help.

Creating a bolt group

See Bolt in the online help for detailed instructions on how to create a bolt group.

It is important that the points you pick to create the bolt group are close enough to the parts you

want to connect. The cut length property of a bolt group defines how far along the bolt axis the parts must be in order to hit the bolt group.

Dimensions are relative to the bolt group origin, which is the first point you pick when creating a bolt group. Tekla Structures sets the x direction of a bolt group using the second point picked. These points are shown as crosses in the illustration below. The dashed line indicates the x direction.

•      Bold dist Y: 100 xy list

•      Bold dist X: 75 175

See also                     

Creating by modifying

You can also create a new bolt group by modifying an existing one. In most cases it is easier to create bolt groups by applying a component including bolt groups, using the following method:

1.    Apply a component.

2.    Explode the component.

3.    Modify the bolt group.

Changing bolted parts

You can change which parts a bolt group connects using the command Detailing > Bolts > Edit Bolted Parts. This command prompts you to reselect the main and secondary parts. Tekla Structures automatically updates bolt length to suit these changes. For more information, see Bolt length calculation in the online help.

Creating holes

Tekla Structures creates holes in the same way as bolts, but you do need to change some of the properties in the Bolt properties dialog box. You can create the following types of holes:

•     Round

•     Oversized

•     Slotted

•     Tapped

Creating round holes

To create a round hole, follow the steps in Tekla Structures calculates the diameter of a round hole as the sum of:

•     Bolt size

•     Tolerance (hole)

To only create a hole, clear all bolt element checkboxes in the Bolt properties dialog box, as shown below:

You also use the Bolt properties dialog box to create slotted holes.

1. Select the checkboxes against Parts with slotted holes to indicate which parts should be slotted.

Tekla Structures counts the pieces of steel from the head of the bolt down. For example, if you select the second checkbox from the head of the bolt, Tekla Structures slots the second piece of steel from the head of the bolt.

3.     Select Slotted in the Hole type list box.

4.    Enter the allowance for the slotted hole in the x and y directions of the bolt group using the Slotted hole X or Slotted hole Y fields.

f2J Slotted hole X or Y

f3J Bolt size

5. If the bolt connects several parts, you may want to rotate alternate holes by 90 degrees. This allows the bolt to move in different directions. To do this, select Even or Odd in the Rotate slots list box.

Use the Bolt properties dialog box to create oversized holes.

1.     Select the checkboxes against Parts with slotted holes to indicate which plies of connection get oversized holes.

2.     To only create a hole, clear all the Include in bolt assembly checkboxes.

3.     Select Oversized in the Hole type list box.

4.     Enter the allowance for the oversized hole in the Oversize field. You can also use a negative value to create smaller (tapped) holes.

Bolt group shape

You have the following options for bolt group shape:

•      Array for rectangular

•      xy list for any shape

•      Circle for circular

Tekla Structures uses the values in Bolt dist X and Bolt dist Y to determine how many bolts the bolt group contains, as shown in the table below:

Tekla Structures calculates bolt length automatically, using the material thicknesses of the connected parts, and other factors. The following settings in the Bolt group properties dialog box affect bolt length calculation:

•      Thread in material

•      Cut length

•      Extra length

Thread in material indicates if the thread of the bolt can extend beyond the bolted parts. Tekla Structures does not use this value when calculating the length of full-threaded bolts.

Cut length indicates the area Tekla Structures should search for parts that belong to the bolt group. Using cut length you can determine whether the bolt will go through one flange or two. In the illustration below, A is the cut length and B is the bolt origin. Tekla Structures calculates the search area as A/2 in both directions from point B.

If there are large gaps between connected parts, the gap is added to the length of the bolt. Tekla Structures calculates bolt length using the the total distance between the first and last surfaces.

Bolt length calculation

•     Bolt group x axis

•     Work plane

The two points you pick to create the bolt group determine the bolt group point of origin and its x direction.

Position on plane Position on plane moves the bolt group perpendicular to the bolt group x axis.

Rotation defines how far the bolt group is rotated around the x axis, relative to the current work plane. For example, you can use this field to indicate on which side of the connected parts you want the bolt head to be.

(2j Top

The starting point values Dx, Dy and Dz move the first end of the bolt group, relative to the bolt group x axis. The end point values move the second end of the bolt group.

•      A positive Dx value moves the starting point towards the end point.

•      Dy moves the end point perpendicular to the bolt group x axis on the current work plane.

•     Slotted hole X = 28, Bolt size = 20, Tolerance = 2 (overall dimension = 50)

•      Starting point, Dx = 100.0