Orthotropy manager

When an orthotropic plate is to be analysed, the user must input the required orthotropy parameters: in total 10 different values.

In order to make the task simpler, the program stores the orthotropy data in a library called Orthotropy. Individual items (types of orthotropy) from this library can be edited in the Orthotropy database manager (a standard SCIA Engineer database manager). Moreover, the orthotropy manager enables the user to select from predefined types of orthotropy. For these types, the ten parameters of orthotropy are not input directly by the user, but are calculated by the program from other specific parameters input by the user.

The parameters for individual types of orthotropy can be divided into three groups:

general,
bending (flexural) effects,
membrane effects.

General parameters

General parameters are common to all types orthotropy.

Name	Specifies then name of the orthotropy.
Type of orthotropy	Selects the required type (see below).

Types of orthotropy

Standard

This is a general orthotropy. For this type of orthotropy, the user must manually input all the required parameters: D11, D22, D12, D33, D44, D55m d11, d22, d12 and d33.

In addition to the general parameters, this type defines the following parameters.

Thickness of plate/wall	Defines the thickness of the orthotropic element.
Material	Selects the material of the plate.

Two heights

This type of orthotropy is suitable for slabs that feature "different height" in two parallel directions. For example, this type can be used for lattice girder slabs.

The slab is composed of panels covered by an in-situ cast topping. The panels and the topping are "linked" together through reinforcement protruding from the panels and entering the topping. Despite it, the final slab features different characteristics in the direction of the panels and in the perpendicular direction.

$image\OrthotropyTwoHights.gif$

Flexural behaviour is defined by the following parameters

Material	Selects the material of the plate.
Effective height d1	The total depth of the final slab.
Effective height d2	The depth of the in-situ cast topping.
Torsion reduction coefficient	Torsion reduction coefficient; using phi_f –> 0, the so called "torsion-weak" plate models can be simulated, providing reduction of lifting corner forces as well as the lower/upper corner main reinforcement.
Shear reduction coefficient	Shear reduction coefficient for a rectangular cross-section.

Membrane behaviour is defined by means of the following parameters

Effective height h1	Specifies the effective height h1 for the membrane effects.
Effective height h2	Specifies the effective height h2 for the membrane effects.
Shear reduction coefficient	Membrane shear reduction coefficient; using phi_m –> 0, the so called "shear-weak" wall models can be simulated, e. g. aimed at excluding such members (maybe masonry walls) from the horizontal stiffening system of the structure.

One direction slab

Similarly to the type above, the final slab is composed of prefabricated panels and in-situ cast topping.

However, the main purpose of the topping is to make the top surface even. The topping does not really co-act with the panels.

$image\OrthotropyOneDirection.gif$

Flexural behaviour is defined by the following parameters

Material	Selects the material of the plate.
CSS	Defines the cross-section of the prefabricated panel.
L	Specifies the axial distance of two adjacent panels.
h	Defines the depth of the in-situ cast topping.

Membrane behaviour is defined by means of the following parameters

Effective height h1	Specifies the effective height h1 for the membrane effects.
Effective height h2	Specifies the effective height h2 for the membrane effects.

Slab with ribs

This type represents a standard ribbed plate with ribs oriented in one direction.

$image\OrthotropyPlateWithRibs.gif$

Flexural behaviour is defined by the following parameters

Rib – rib input type	Selects the way the rib dimensions are input. CSS lib The rib is selected from the cross-section manager. Input The dimensions of the rib are input directly by the user.
Rib – cross-section	(only for rib input type set to CSS lib) Selects the required cross-section of the rib from the project database of defined cross-sections.
Rib – spacing a1	Defines the distance between two adjacent ribs.
Rib – material	(only for rib input type set to Input) Selects the material of the rib.
Rib – thickness, t	(only for rib input type set to Input) Defines the width of the rib.
Rib – depth, h	(only for rib input type set to Input) Defines the depth of the rib.
Slab – material	Selects the material of the plate.
Slab – height, h	Defines the depth of the plate.

Membrane behaviour is defined by means of the following parameters

Effective height h1	Specifies the effective height h1 for the membrane effects.
Effective height h2	Specifies the effective height h2 for the membrane effects.

Grid work

This type represents a ribbed plate with ribs oriented in two perpendicular directions.

$image\OrthotropyGridwork.gif$

Flexural behaviour is defined by the following parameters

beam 1

Spacing	Defines the distance between ribs in direction 1.
Material	Selects the material of the rib in direction 1.
Width of beam	Defines the width of the rib in direction 1.
Depth of beam	Defines the depth of the rib in direction 1.

beam 2

Spacing	Defines the distance between ribs in direction 2.
Material	Selects the material of the rib in direction 12.
Width of beam	Defines the width of the rib in direction 2.
Depth of beam	Defines the depth of the rib in direction 2.

Membrane behaviour is defined by means of the following parameters

Effective height h1	Specifies the effective height h1 for the membrane effects.
Effective height h2	Specifies the effective height h2 for the membrane effects.