Haunch beam

A haunch beam is a 1D member whose cross-section varies along the length of the 1D member. It is also possible that a part of the 1D member is of a constant cross-section and only the remaining part contains a haunch.

Therefore, the list of haunch beam parameters may be rather long. It contains the following items:

Haunch placement	Specifies the location of the haunch on the 1D member.
Cross-section	Tells which cross-section will be used to form the haunch. (see Note below ! )
List of dimensions that can vary along the haunch length	This list contains the dimension of the assigned cross-section that may vary along the haunch length.
Alignment	Specifies the alignment of the haunch.
Length of haunch	Determines the length of the haunch. This item is not accessible if the haunch is defined per the whole 1D member, i.e. from one 1D member end to the other.
Co-ordinate definition	Tells if the haunch length is input in relative 1D member co-ordinate (i.e. from zero to one) or in absolute values (i.e. for example in metres). This item is not accessible if the haunch is defined per the whole 1D member, i.e. from one 1D member end to the other.

$image\Dlg_Picture_Haunch.gif$

Haunch placement

The variants for the placement are:

From start	$image\Wnd_Haunch_Left.gif$	The haunch starts at the starting point of the 1D member and its length is determined by the value input in cell Length of haunch.
From end	$image\Wnd_Haunch_Right.gif$	The haunch starts at the end point of the 1D member and its length is determined by the value input in cell Length of haunch.
Symmetrical	$image\Wnd_Haunch_Symmetric.gif$	The haunch is located at both ends of the 1D member its length is determined by the value input in cell Length of haunch.
From start – whole length	$image\Wnd_Haunch_Left_whole.gif$	The cross-section varies along the whole 1D member length. The haunch starts at the starting point of the 1D member.
From end – whole length	$image\Wnd_Haunch_Right_whole.gif$	The cross-section varies along the whole 1D member length. The haunch starts at the end point of the 1D member.
Symmetrical – whole length	$image\Wnd_Haunch_Symmetric_whole.gif$	The haunch is at both sides of the 1D member, is symmetrical and extends from each of the 1D member ends towards the 1D member centre.

Cross-section

The cross-section defined here replaces the original cross-section of the 1D member on which the haunch is defined. That means that the original 1D member cross-section can be of any type. When a haunch is defined on a 1D member, the original cross-section is completely forgotten and the haunch cross-section is applied.

Examples

A haunch on a basic cross-section of I shape with the height equal to 300 millimetres and top flange thickness 50 millimetres.

Height of haunch	Shape of haunch
H = 500 mm	$image\Wnd_Haunch_Sample_500.gif$
H = 1000 mm	$image\Wnd_Haunch_Sample_1000.gif$
H = 1000 mm and top flange thickness increased to 200 mm	$image\Wnd_Haunch_Sample_1000_200.gif$

Note: It is important to be aware of the fact that only specific cross-sections can be used for haunches. For example, it is not possible to use a rolled cross-section as it not possible to change its height over the length of a 1D member.

List of dimensions that can vary along the haunch length

The cross-section defined for a haunch can vary in size along the haunch length. However, not all the possible dimensions of the cross-section can vary. The list of dimensions that may be variable is limited and is stated in the haunch property dialogue. What’s more, these dimensions are highlighted in yellow both in the haunch property dialogue and in the cross-section editing dialogue.

Thanks to the "highlighted" dimensions the cross-section changes linearly its shape along the haunch. The haunch starts with the cross-section specified by the "highlighted" values. And at the end of the haunch there is the cross-section of standard dimensions as defined in the Cross-section manager.

Alignment

The alignment of the haunch may be of several types.

In order to explain clearly the meaning of individual option, let’s assume a horizontal 1D member with a haunch whose cross-section is of variable height as well as of variable width.

Default		The alignment of the haunch is adjusted according to the Insertion point of the 1D member. E.g. if the Insertion point of the 1D member is set to Top, Top surface alignment of the haunch is used.
Centre line	$image\Wnd_Haunch_Left.gif$ side view $image\Wnd_Haunch_Plan_Centre.gif$ plan view	In plan view as well as in side view the midline of the 1D member remains straight and horizontal. Both left and right surface are inclined to allow the cross-section change its width. The centre line of the 1D member (i.e. the centroid axis) of the 1D member remains straight. Both top and bottom surface are symmetrically inclined to allow the cross-section change its height.
Top surface	$image\Wnd_Haunch_Top_surface.gif$ side view	The top surface of the 1D member remains flat and horizontal. The bottom surface is inclined in order to provide for the change of the height. In plan view, the midline of the 1D member is straight. Both left and right surface are symmetrically inclined to allow the cross-section change its width.
Bottom surface	$image\Wnd_Haunch_Bottom_surface.gif$ side view	The bottom surface of the 1D member remains flat and horizontal. The top surface is inclined in order to provide for the change of the height. In plan view, the midline of the 1D member is straight. Both left and right surface are symmetrically inclined to allow the cross-section change its width.
Left surface	$image\Wnd_Haunch_Plan_Left.gif$ plan view	The left surface of the 1D member remains flat and horizontal. The right surface is inclined in order to provide for the change of the width. In side view, the midline of the 1D member is straight. Both top and bottom surface are symmetrically inclined to allow the cross-section change its height.
Right surface	$image\Wnd_Haunch_Plan_Right.gif$ plan view	The right surface of the 1D member remains flat and horizontal. The left surface is inclined in order to provide for the change of the width. In side view, the midline of the 1D member is straight. Both top and bottom surface are symmetrically inclined to allow the cross-section change its height.