Sheeting settings

The sheeting is completely defined by means of:

basic geometrical parameters,
settings determining its position in a model.

The settings for the sheeting are:

Name	Name of sheeting settings set.
Sheeting Lib	Type of defined sheeting.
Position z	Specifies the position in z direction of the member, i.e. either the topside or the bottom side.
k	The value of coefficient k depends on the number of sheetings: k = 2 for 1 or 2 lateral sheetings, k = 4 for 3 or more sheetings.
Sheeting position	The position of the sheeting may be either positive or negative. Positive means that the sheeting is assembled in a way so that the width is greater at the top side. Negative means that the sheeting is assembled in a way so that the width is greater at the bottom side.
Bolt position	Bolts may be located either at the top or bottom side of the sheeting.
Bold pitch	Bolts may be either: in every rib (i.e. "br"), in each second rib (i.e. "2 br").
Frame distance	The distance of frames (i.e. the span of transverse bonds).
Sheeting length	The length of the transverse bond.

Geometry

Position x1	Value x1 specifies the begin-point of the sheeting on the beam.
Position x2	Value x1 specifies the end-point of the sheeting on the beam.
Co-ordinate definition	Defines the co-ordinate system in which the position x is inputted.
Origin	Defines the origin from which the position x is measured.

The procedure to adjust the sheetings

Open service Steel:
1. either using the process toolbar menu function Steel,
2. or using the design menu function Design > Steel members.

Select function Steel sheeting and open it.
Type required values and select appropriate options.
Confirm with [OK].
Select the member where the data are to be defined.
End the function.

Note: sheetings are not available for codes that do not have Mcr: AISC-ASD, Korean Standard and GBJ 17-88.

Note: For more info, see chapter Use of sheetings in Steel Code Check Theoretical Background.

Composite analysis model

When using the composite analysis model, steel beams are defined as plate ribs attached to a composite deck or a metal deck. In both cases, the information defining the sheeting, aka profiled steel sheeting, is already available from the analysis model and it is therefore not necessary to input sheeting member data. The steel code check will detect automatically the profiled steel sheeting from the composite analysis model and take it into account in the LTB check.

Information retrieved from the Composite Analysis Model

As not all the sheeting settings are available in the composite analysis model, the following assumptions are made:

Sheeting Lib

obtained directly from the composite deck properties

The determination of the k-value is based on EN 1993-1-3 art. 10.1.5.2(4) instead of the method defined in the manual input of sheeting data.

The value of coefficient k depends on the statical system of the profiled steel sheeting on both sides of the considered beam.

- in case there is a supported span on both sides of the considered beam, k=4 is used.

- in all other cases, k=2 is used.

Sheeting position

The position of the sheeting is always assumed positive.

Bolt position

Bolts are always assumed at the bottom side of the sheeting.

Bolt pitch

obtained directly from the composite beam data (or default value defined in the composite setup). The composite beam settings allow:

- every trough (i.e. br)

- every 2nd trough (i.e. 2br)

- every 3rd trough (is taken into account as 2br)

For IBC projects, the value for "br" can not be set directly in the composite setup. Therefore, the value is always taken as "br" (i.e. every rib)

Frame distance

The distance of frames, calculated from the composite analysis model. Depending on the statical system of the sheeting on each side of the beam, the distance will be:

sheeting system on the left side of the beam	sheeting system on the right side of the beam	frame distance value
none	none	L (= span length of the considered beam, used as an upper limit value)
none	supported span	DR (= distance to the adjacent beam or edge on the right side of the beam)
none	cantilever	L
supported span	none	DL (= distance to the adjacent beam or edge on the left side of the beam)
supported span	supported span	max(DL;DR)
supported span	cantilever	DL
cantilever	none	L
cantilever	supported span	DR
cantilever	cantilever	L

The sheeting is considered having a supported span when there is an adjacent beam on the corresponding side.

The sheeting is considered as a cantilever when it has a free edge on the corresponding side.

in case DR (resp. DL) is greater than L, the composite analysis model considers, that there is no adjacent entity (beam or free edge) on the right (resp. left) side of the beam.

Sheeting length

defined in the composite setup or in the composite beam data

Perpendicularity

Information from the composite analysis is automatically taken into account in the LTB check, provided that the beam and the profiled steel sheeting are perpendicular. The condition for that is, that the angle between the beam and sheeting is comprised between 80° and 100° (90° +/- 10°). When the angle is not within that interval, the steel sheeting is considered ineffective and is not taken into account.

Overriding the composite beam data

The information provided by the composite analysis model for the LTB check will be detailed in the output of the steel code check. In case that information would be unsatisfying, it is possible to override it by defining sheeting member data in the steel code check service, as described at the top of this page.

When defined, the sheeting member data has priority over the information from the composite analysis model regarding the sheeting data for the LTB check.