# ASME BTH-1 Members (2020)

ASME BTH-1 Members (2020) - provides implementation according to Design of Below-the-Hook Lifting Devices 2020.

This Standard supports double symmetric I-shapes, single symmetric channels, circular tubes, rectangular tubes, circular and rectangular bars.

To add the standard execute

from the ribbon:Press to Set Standard Custom Settings

Data from Beam Member Finder is used automatically. If beam members are not recognized press .

Section Build Type - define whether section is rolled or built-up.

Section Net Area (Para. 3-2.1) - effective net tensile area (Described in paragraph 3-2.1) [Default value = 0].

Beam Brace Type (Para. 3-2.3) - define whether beam is braced against twist or lateral displacement of the compression element at the ends of the unbraced length. [Default value = Yes] Required to calculate the value of C_LTB (Lateral - torsional buckling strength coefficient) for Rectangular Bars, I-shape Sections and Channels (Described in paragraph 3-2.3).

C_mx (Para. 3-2.4) - set coefficient applied to bending term in interaction equation about the x-axis for prismatic members and dependent on column curvature caused by applied moments, (Described in paragraph 3-2.4) [Default value = 1]. Lower value may be used if justified by the analysis. Note: C_mx is also used as C_m for cylindrical members in this implementation.

C_my (Para. 3-2.4) - define coefficient applied to bending term in interaction equation about the y-axis for prismatic members and dependent on column curvature caused by applied moments, (Described in paragraph 3-2.4) [Default value = 1] Lower value may be used if justified by the analysis.

Calculate Cb (based on moment diagram, Para. 3-2.3) - turn on to calculate C_{b} using equation 3-12, turn off to set it manually in characteristic - User Defined:

M_{1} = smaller bending moment at the end of the unbraced length of a beam taken about the major axis of the member.

M_{2} = larger bending moment at the end of the unbraced length of a beam taken about the major axis of the member.

Note: When Calculate Cb option is turned ON and the bending moment at any point within an unbraced length is larger than that at both ends of this length, C_{b} is taken as unity.

Calculate Asymmetric Shapes as Symmetric - turn on to treat asymmetric shapes as symmetric in calculations. Min width and thickness are used.

Calculate Beyond Limits (Table 3-2.2-1 or Para. 3-2.3-6) - turn on to calculate beam members NOT satisfying limits from Table 3-2.2-1 or paragraph 3-2.3-6, using a yield strength reduced to satisfy those limits. Otherwise, if turn off - error code is displayed when beam member does not satisfy limits conditions.

Nominal Design Factor (Para. 3-1.3.1) - define 2.00 for Design Category A lifters, 3.00 - B, 6.00 - C (Described in paragraph 3-2.3.1).