pressureBulkheadType

Describes how a pressure bulkhead is built: the sheet that closes the cross section of the fuselage, its shape — flat or curved — and its reinforcements. A bulkhead of a fuselage (pressureBulkheadAssemblyPositionType) places it at a frame; the surface it closes is described there.

Flat bulkhead

A flat bulkhead is the plane surface enclosed by the frame, typically at the front end of the pressurised fuselage. It is stiffened by <reinforcementNumberVertical> vertical and <reinforcementNumberHorizontal> horizontal profiles of the elements <structuralElementVerticalUID> and <structuralElementHorizontalUID>. The reinforcements are evenly distributed: n vertical reinforcements divide the width of the surface into n + 1 equal parts, and the horizontal ones divide its height in the same way.

Curved bulkhead

A curved bulkhead is a spherical calotte, typically at the rear end of the pressurised fuselage. In the plane of the frame, the edge of the calotte is a circle with the radius r = <bulkheadCalotteRadiusAtFrame> around the centroid of the surface enclosed by the frame. The calotte is curved backwards, towards +x, and its apex lies <maxFlectionDepth> = t behind that plane, so that its sphere has the radius R = (r² + t²) / (2t). Between the frame and the edge of the calotte, a flat ring closes the bulkhead. <reinforcementNumberRadial> radial reinforcements of the element <structuralElementRadialUID> run from the edge to the apex at equal angles.

Two pressure bulkheads. (a) Flat bulkhead at the frame at x = 1.5 m, seen from behind: the surface enclosed by the frame with five vertical and three horizontal reinforcements, which divide its width into six and its height into four equal parts. (b) Curved bulkhead at the frame at x = 20 m in the section y = 0: a calotte curved backwards with the radius bulkheadCalotteRadiusAtFrame = 1.45 m around the centroid of the frame and the depth maxFlectionDepth = 0.55 m, and a narrow flat ring between the frame and the edge of the calotte

The figure shows the two bulkheads of the example. (a) The flat bulkhead at the frame at x = 1.5 m has five vertical and three horizontal reinforcements, which divide its width into six and its height into four equal parts. (b) The curved bulkhead at the frame at x = 20 m, in the section through its centroid, has a calotte of 1.45 m radius and 0.55 m depth; the flat ring between the frame and the calotte is about 0.1 m wide.

On which side of the sheet the reinforcements stand, and at which angle the first radial reinforcement lies, is not specified yet.

Rules

The radius of the calotte is smaller than the smallest distance from the centroid to the frame, so that the flat ring remains.
A number of reinforcements greater than 0 comes with the element of their profile.

Example

The elements of the two bulkheads of the example:

<pressureBulkheads>
    <pressureBulkhead uID="FwdPressureBulkhead">
        <name>Forward pressure bulkhead</name>
        <sheetElementUID>BulkheadFlat</sheetElementUID>
        <reinforcementNumberVertical>5</reinforcementNumberVertical>
        <structuralElementVerticalUID>ZFrame</structuralElementVerticalUID>
        <reinforcementNumberHorizontal>3</reinforcementNumberHorizontal>
        <structuralElementHorizontalUID>TStringer</structuralElementHorizontalUID>
    </pressureBulkhead>
    <pressureBulkhead uID="AftPressureBulkhead">
        <name>Aft pressure bulkhead</name>
        <sheetElementUID>BulkheadCalotte</sheetElementUID>
        <bulkheadCalotteRadiusAtFrame>1.45</bulkheadCalotteRadiusAtFrame>
        <maxFlectionDepth>0.55</maxFlectionDepth>
        <reinforcementNumberRadial>16</reinforcementNumberRadial>
        <structuralElementRadialUID>TStringer</structuralElementRadialUID>
    </pressureBulkhead>
</pressureBulkheads>

Flat and curved pressure bulkhead

Attributes

Name	Type	Use	Description
`@externalDataDirectory`	`xsd:string`	optional	Directory of the external file the element was read from, as URI
`@externalDataNodePath`	`xsd:string`	optional	Path of the parent element in the merged dataset, at which the element was inserted from an external file
`@externalFileName`	`xsd:string`	optional	Name of the external file the element was read from
`@uID`	`xsd:ID`	required	UID

Child elements

Name	Type	OccurrenceHow often the element may appear at this place. The schema writes it as minOccurs and maxOccurs on the declaration.	Default	Description
sequenceThe children below must appear in exactly this order. Each may repeat as often as its own occurrence allows.
`name`	`stringBaseType`	[0..1] optional		Name
`description`	`stringBaseType`	[0..1] optional		Description
`sheetElementUID`	`stringUIDBaseType`	[1..1] required		UID of the sheetBasedStructuralElement of the bulkhead
choiceExactly one of the alternatives below may appear, unless the occurrence next to this line says otherwise.
sequenceThe children below must appear in exactly this order. Each may repeat as often as its own occurrence allows.
`reinforcementNumberVertical`	`integerBaseType`	[0..1] optional	`0`	Number of vertical reinforcements, evenly distributed across the width (default 0)
`structuralElementVerticalUID`	`stringUIDBaseType`	[0..1] optional		UID of the profileBasedStructuralElement of the vertical reinforcements
`reinforcementNumberHorizontal`	`integerBaseType`	[0..1] optional	`0`	Number of horizontal reinforcements, evenly distributed over the height (default 0)
`structuralElementHorizontalUID`	`stringUIDBaseType`	[0..1] optional		UID of the profileBasedStructuralElement of the horizontal reinforcements
sequenceThe children below must appear in exactly this order. Each may repeat as often as its own occurrence allows.
`bulkheadCalotteRadiusAtFrame`	`doubleBaseType`	[1..1] required		Radius of the edge of the calotte in the plane of the frame [m]
`maxFlectionDepth`	`doubleBaseType`	[1..1] required		Depth of the calotte: distance of its apex behind the plane of the frame [m]
`reinforcementNumberRadial`	`integerBaseType`	[0..1] optional	`0`	Number of radial reinforcements at equal angles (default 0)
`structuralElementRadialUID`	`stringUIDBaseType`	[0..1] optional		UID of the profileBasedStructuralElement of the radial reinforcements

pressureBulkheadType

Attributes

Child elements

Used by

In a dataset · 1 path

In the schema · 1 declaration