Software Forms > Backdoor Data Form > Miscellaneous

Miscellaneous

Membrane Only Shells (Default = False)

[Boolean, Nastran Only] If set to true, stiffened panels will be written to the Properties and Materials (*.PM1) FEM output file with membrane-only properties. In other words, bending stiffness and membrane-bending coupling terms will not be included.

Biaxial Buckling Field Stiffening - tensile (Default = 1.0)

[+Real] The tensile and compressive field stiffening factors provides a method for factoring only the tensile or compressive portion of the buckling load in component sizing. The tension factor (FactorTF) is applied to either the Nx or Ny load that is in tension. If both Nx and Ny are tensile, then the factor is applied to the lower of these two values. A summary of which tensile or compressive stiffening field factors are applied is presented below.

    If Nx > 0 and Ny > 0:

 

        If Nx < Ny:

            Nx'=Nx*FactorTF

            Ny'=Ny

 

        If Nx > Ny:

            Nx'=Nx

            Ny'=Ny*FactorTF

 

    If Nx < 0 and Ny < 0:

 

        If Abs(Nx) < Abs(Ny):

            Nx'=Nx*FactorCF

            Ny'=Ny

 

        If Abs(Nx) > Abs(Ny):

            Nx'=Nx

            Ny'=Ny*FactorCF

 

    If Nx ≥ 0 and Ny ≤ 0:

 

        Nx' = Nx * FactorTF

        Ny' = Ny

 

    If Nx ≤ 0 and Ny ≥ 0:

 

        Nx' = Nx

        Ny' = Ny * FactorTF

These factors only effect buckling loads:

Biaxial Buckling Field Stiffening - compression (Default = 1.0)

[+Real] The tensile and compressive field stiffening factors provide a method for factoring only the tensile or compressive portion of the buckling load in component sizing. The compression factor (FactorCF) is only applied if both Nx and Ny are compressive. The factor is applied to the lower magnitude of Nx or Ny. A summary of which tensile or compressive stiffening field factors are applied is presented above.

Curved Panels - Use Superimposed Pressure (Default = False)

[Boolean] By default, HyperSizer will not superimpose pressure for curved panels. HyperSizer's superimposed pressure formulation is based on flat panels. The assumption is that for curved panels, the pressure will be primarily reacted in hoop tension or compression. Activating this flag (True) will cause HyperSizer to superimpose pressure to a curved panel as if it were flat.

Curved Panels - Use Flat Panel Buckling (Default = False)

[Boolean] By default, buckling methods that are listed as "flat" (e.g. Panel Buckling, Flat, Simple BC, ...) will be deactivated for curved panels because by not taking curvature into account, they tend to be over conservative. For academic reasons, you can activate this flag (True) to see the buckling load for a curved panel as if it were flat.

Curved Panels - Use Full Pressure for Local Bending (Default = False)

[Boolean] HyperSizer includes a method for superimposing local pressure bending moment/shear loads for the facesheet between stringers. However, in the case of curved panels, part of the pressure load is carried in membrane (hoop) and part of the pressure load is carried by this additional bending moment. By default, HyperSizer calculates and applies only this bending portion to the skin. If you activate this flag (True), HyperSizer will not separate the membrane and bending portion and calculate the superimposed bending moment as if none of the pressure is reacted in the hoop. Local pressure superposition of flat panels assumes that the pressure reacts completely in bending.

Nastran Composite Failure Theory (Default = none)

[String, Nastran Only] The string entered here will be exported to the PCOMP card as the Failure Theory (FT) field. This will not affect HyperSizer's analysis. Acceptable choices for Nastran analysis are "HILL" (= Tsai Hill), "HOFF" (= Hoffman), "TSAI" (= Tsai Wu), or "STRN" (= Max Strain). Exclude the quotes.

Limit number of candidate designs (Default = 100,000)

[+Integer] There is a limit on the number of candidate designs to be analyzed per component. The upper limit is 2,500,000. Large numbers of candidate designs can significantly slow the sizing process.

Use Average Tension/Compression Modulus (Default = False)

[Boolean] By default, HyperSizer uses tension moduli when working with tension loads and compressive moduli when working with compression loads. Activating this flag (True) will cause HyperSizer to average the tension and compression moduli before conducting any thermoelastic stress/strain or failure analysis. The exception to this is buckling analysis. All buckling critical loads (including local buckling, panel buckling, and crippling) are always carried out using compressive moduli. This flag will also affect stiffnesses written to the PM1 file. If the flag is False, compression moduli will be exported if the controlling loads are compressive and tension moduli will be exported if the controlling loads are tensile.

Remove Added Weight for Reporting (Default = True)

[Boolean] By default, unit weights reported on the Sizing form and Project form will exclude added weight or non-structural mass that is added on the Options tab. Deactivating this flag (False) will cause HyperSizer to report all weights as total weight including structural and non-structural mass. This flag will also determine whether non-structural mass weights are included in the HyperFEA convergence output. This flag will not affect the weights exported to the finite element model PM1 file.

Include Density on MAT2 Card Output (Default = False)

[Boolean] Not supported.

Generate Diverse Requested Designs (Default = True)

[Boolean] When requesting N multiple designs for a component, rather than select the first n candidate designs with positive margins, this flag (True) will cause HyperSizer to return candidate designs that are diverse. This means that each candidate design will have different materials, thicknesses and layups for each object rather than small variations that all use the same materials. This flag aids in mixing and matching laminates for compatibility on the Composites Analysis form.

Crippling Use Damage Tolerance Allowables

[Boolean] See Crippling.

Crippling Exclude Facesheet in Force Summation

[Boolean] See Crippling.

Crippling Include Bonded Flange-Facesheet in Force Summation

[Boolean] See Crippling.

Buckling On Elastic Foundation Use Hetenyi Spring Constant (Default = False)

[Boolean] For the Uniaxial Family - reinforced Core Sandwich panel concept - local buckling of the facesheets and webs use buckling on an elastic spring theory. The default is to use the simplest spring constant which is,

K = Efoam/hcore

In some situations, this constant can yield over-conservative results. If this flag is activated (True), the spring constant will take on the following form suggested by Hetenyi,

K=0.28 Efoam(Efoam/DFS,11)1/3

Tube Local Wall Buckling Use SP-8007 Knockdown Factor (Default = True)

[Boolean] Activating this flag (True) will cause HyperSizer to calculate and apply the SP-8007 knockdown factor for buckling of a cylinder when reporting local wall buckling results for the circular tube beam concept. If this flag is False, HyperSizer will use the Tube Local Wall Knockdown Factor specified below.

Tapered Tube Include Beam-Column in Interlaminar Shear (Default = False)

[Boolean] For the Circular Tube Beam - Tapered Tube concept - the out-of-plane stress is calculated for the "kick" load at the intersection of the tapered section and the constant cross-section. By default, any beam column analysis does not contribute to this out-of-plane load. Activating this flag (True) will cause HyperSizer to include beam-column loads when calculating this stress.

Tube Local Wall Buckling User Specified Knockdown Factor (Default = 1.0)

[+Real] If the SP-8007 Knockdown Factor is turned off, HyperSizer will use the knockdown factor specified here for local wall buckling of the circular beam concept. If the SP-8007 correction factor is turned on, this factor is ignored.