4.1.1.1.5. CSA o86-19 Glulam Design - Interaction

The following functions are provided for checking the moment/compression interaction for a glulam column.

Contains the code designc clauses

checkInterEccPf(Pf: float, e: float, Pr: float, Mr: float, PE: float) → float[source]

Checks interaction for eccentrically loaded members in compression.

limitations:

  • For glulam, does not apply to the weak axis of bending.

  • Assumes the bending diagram has no points of inflection in it

  • Assumes the member is constraind at both ends.

  • Does not consider any amplification due to large P-delta effects.

See Section 5.1 of the wood hand book for more information.

This is valid, because for eccentriclly loaded members the maximum moment occurs at the midspan of the member, litle p delta effects occur at the center of the member.

Assumes consistent units used, e.g. N, m, Nm

Parameters

  • Pf (float) – The factored compression force.

  • e (float) – The eccentricty the load applies at, in m.

  • Pr (float) – The compression resistance.

  • Mr (float) – The moment resistance.

Returns

  • float

  • The interaction utilization in the form (top utilization , middle utilization)

checkInterEccPfColumn(element: BeamColumnGlulamCsa19, Pf: float, e: float, Mr: float, knet: float = 1, useX: bool = True, useFire: bool = False, kSE=1, kT=1) → float[source]

Checks interaction for eccentrically loaded members in compression. Moment is applied in x if useX is set to true. For glulam,

limitations:

  • For glulam, does not apply to the weak axis of bending.

  • Assumes the bending diagram has no points of inflection in it

  • Assumes the member is constraind at both ends.

  • Does not consider any amplification due to large P-delta effects.

See Section 5.1 of the wood hand book for more information.

This is valid, because for eccentriclly loaded members the maximum moment occurs at the midspan of the member, litle p delta effects occur at the center of the member.

Parameters

  • Pf (float) – The factored compression force, in N.

  • e (float) – The eccentricty the load applies at, in m.

kSEfloat, optional

The service condition factor, used when calculating kC. The default is 1.

kTfloat

The treatment condition factor, used when calculating kC. The default is 1.

Returns

  • float

  • The interaction utilization.

checkInterTimberGeneric(Pf: float, Pr: float, Mf: float, Mr: float, PE: float) → float[source]

Checks interaction for a generic timber member.

The force in the column is factored up by little p-delta loads.

Parameters

  • Pf (float) – The factored compression force.

  • Pr (float) – The compression resistance.

  • Mf (float) – The factored moment force.

  • Mr (float) – The moment resistance.

  • PE (float) – The Euler bockling force for the column.

Returns

The interactionutilization.

Return type

float

checkPE(E05: float, I: float, Lei: float, kSE: float = 1, kT: float = 1)[source]

Calculates the critical buckling load for a typical column based on the critical buckling length.

Parameters

  • E (float) – The elastic modulus.

  • I (float) – The moment of Inertia in the direction i.

  • Lei (float) – The effectice buckling length in the direction i.

  • kSE (float, optional) – The service k factor. The default is 1.

  • kT (float, optional) – The treatment k factor. The default is 1.

Returns

The critical buckling load in N.

Return type

float

checkPEColumn(element: BeamColumnGlulamCsa19, knet: float = 1, useFire: bool = False, kSE=1, kT=1) → float[source]

Checks the Pr for a beamcolumn.

Pr and kzbg is calculated according to 7.5.8.5, and kc is calculated according to 7.5.8.6

If KSE or KT are not equal to one, they must be included in the equation, in addition to knet. knet should still be the product of all k factors. These terms are seperated out due to clause 7.5.8.6, which seperates kSE and KT when calcualting the factor Kc.

Parameters

  • element (BeamColumnGlulamCsa19) – The glulam element to check. Can also be solid timber elements.

  • knet (float, optional) – The product of all standard k factors, including kd, kse, etc. The default is 1.

  • useFire (bool, optional) – A toggle that makes the beam use it’s fire section when selected. The default is False, which uses no fire section.

  • kSE (float, optional) – The service condition factor, used when calculating kC. The default is 1.

  • kT (float) – The treatment condition factor, used when calculating kC. The default is 1.

Returns

The output in N.

Return type

Pr