FeResPost Web Site                     FeResPost Online User Manual

VII.4.4.1 Post-processing of stress Results

VII.4.4.1.1 “getVonMisesMax” function

Function “getVonMisesMax” in “ExtractionCriteria” VBA module extracts the maximum Von Mises equivalent stress on a Group of elements and on a selection of layers. The arguments of the function are:

1.
A String corresponding to the name of the load case for which stresses are extracted.
2.
A String corresponding to the location of extraction points on the elements. (For example: “Elements”, “ElemCenters” or “ElemCorners”.)
3.
A selection of layers. This is a range of cells containing Integer or String values that are converted to a list of layers by “layersFromRange” method of “UTIL” VBA module.
4.
A String corresponding to the Group of elements on which stresses are extracted.
5.
Two optional String arguments corresponding to the name of the GMSH file in which the envelope of maximum equivalent stress shall be saved, and the name of the Result by which the Result is referred to in GMSH.

The function returns an Array of one line and six columns:

1.
The element ID for maximum equivalent stress,
2.
The node ID for maximum equivalent stress,
3.
The layer ID for maximum equivalent stress,
4.
The sub-layer ID for maximum equivalent stress,
5.
The coordinate system ID which is always “NONE”,
6.
The maximum Von Mises equivalent stress.

The use of “getVonMisesMax” is illustrated in “post_sandwich” spreadsheet.

VII.4.4.1.2 “getShellVonMisesMax” function

Function “getShellVonMisesMax” in “ExtractionCriteria” VBA module extracts the maximum Shell Von Mises equivalent stress on a Group of elements and on a selection of layers. The arguments of the function are:

1.
A String corresponding to the name of the load case for which stresses are extracted.
2.
A String corresponding to the location of extraction points on the elements. (For example: “Elements”, “ElemCenters” or “ElemCorners”.)
3.
A String corresponding to the Group of elements on which stresses are extracted.
4.
Two optional String arguments corresponding to the name of the GMSH file in which the envelope of maximum equivalent stress shall be saved, and the name of the Result by which the Result is referred to in GMSH.

The function returns an Array of one line and six columns:

1.
The element ID for maximum equivalent stress,
2.
The node ID for maximum equivalent stress,
3.
The layer ID for maximum equivalent stress,
4.
The sub-layer ID for maximum equivalent stress,
5.
The coordinate system ID which is always “NONE”,
6.
The maximum Von Mises equivalent stress.

The difference between “getShellVonMisesMax” and “getVonMisesMax” is that one does not need to provide a selection of layers argument: the extraction is automatically done on layers “Z1” and “Z2”. The function returns a single value: the maximum Von Mises equivalent stress. The use of “getShellVonMisesMax” is illustrated in “post_sandwich” spreadsheet.

VII.4.4.1.3 “getHoneycombCoreAirbusRF” function

Function “getHoneycombCoreAirbusRF” in “ExtractionCriteria” VBA module calculates the minimum honeycomb reserve factor on a Group of elements using the so-called “Airbus” criterion:

RF = 1 FoSτL σL 2 + τW σW 2,

in which τL and τL are the honeycomb longitudinal and transverse shear components of Cauchy stress tensor and σL and σW the corresponding allowables.

The arguments of the function are:

1.
A String corresponding to the name of the load case for which Cauchy stress tensor is extracted.
2.
A String corresponding to the location of extraction points on the elements. (For example: “Elements”, “ElemCenters” or “ElemCorners”.)
3.
A String corresponding to the Group of elements on which stresses are extracted.
4.
A String corresponding to the layer on which stresses are extracted.
5.
A Real safety factor.
6.
A Real value corresponding to the honeycomb longitudinal shear stress allowable σL.
7.
A Real value corresponding to the honeycomb transverse shear stress allowable σW .
8.
Two optional String arguments corresponding to the name of the GMSH file in which the envelope of maximum equivalent stress shall be saved, and the name of the Result by which the Result is referred to in GMSH.

The function returns an Array of one line and eight columns:

1.
The element ID for minimum reserve factor,
2.
The node ID for minimum reserve factor,
3.
The layer ID for minimum reserve factor,
4.
The sub-layer ID for minimum reserve factor,
5.
The coordinate system ID for minimum reserve factor,
6.
The value of longitudinal shear stress τL for minimum reserve factor,
7.
The value of transverse shear stress τW for minimum reserve factor,
8.
The minimum reserve factor.

The use of “getHoneycombCoreAirbusRF” is illustrated in “post_sandwich” spreadsheet.

VII.4.4.1.4 “getHoneycombCoreMaxShearRF” function

Function “getHoneycombCoreMaxShearRF” in “ExtractionCriteria” VBA module calculates the minimum honeycomb reserve factor on a Group of elements using a maximum shear criterion:

MoS = σW FoS * τ - 1,

in which τ is the maximum shear stress and σW the transverse shear allowable.

The arguments of the function are:

1.
A String corresponding to the name of the load case for which Cauchy stress tensor is extracted.
2.
A String corresponding to the location of extraction points on the elements. (For example: “Elements”, “ElemCenters” or “ElemCorners”.)
3.
A String corresponding to the Group of elements on which stresses are extracted.
4.
A String corresponding to the layer on which stresses are extracted.
5.
A Real safety factor.
6.
A Real value corresponding to the honeycomb longitudinal shear stress allowable σL. (This allowable is not used in the calculation.)
7.
A Real value corresponding to the honeycomb transverse shear stress allowable σW . (Only this allowable is used in the calculation.)
8.
Two optional String arguments corresponding to the name of the GMSH file in which the envelope of maximum equivalent stress shall be saved, and the name of the Result by which the Result is referred to in GMSH.

The function returns an Array of one line and eight columns:

1.
The element ID for minimum reserve factor,
2.
The node ID for minimum reserve factor,
3.
The layer ID for minimum reserve factor,
4.
The sub-layer ID for minimum reserve factor,
5.
The coordinate system ID for minimum reserve factor,
6.
The value of longitudinal shear stress τL for minimum reserve factor,
7.
The value of transverse shear stress τW for minimum reserve factor,
8.
The minimum reserve factor.

The use of “getHoneycombCoreMaxShearRF” is illustrated in “post_sandwich” spreadsheet.