Description

If you are like me you may have found out the hard way that the values published in the 13th Edition AISC manual for the principle axis section modulus for angles are incorrect. Although the values for principle axes moment of inertia are correct, an incorrect value of “c” was consistently used to obtain the section modulus. In addition to the principle axis properties and orientation of the principle axes with respect to the geometric axes, Version 2.0 now includes the following:

1. The ability to specify orientation of the angle legs and to subsequently calculate the section properties about the modified axis orientation. The following are addressed SLVD Unequal leg – short leg vertically SLVU Unequal leg – short leg vertically up LLVD Unequal leg-long leg vertically down LLVU Unequal leg – long leg vertically up EQVLD Equal leg – long leg vertical down EQVLU Equal leg – long leg vertically up

2. Calculation of the Beta w factor which is utilized in the 13th Edition AISC Manual – equation F10-6 for calculation of allowable moments about the major principle axis for unequal length angles. The proper sign of Beta w is also calculated which is dependent upon whether the shear center is in flexural compression or tension.

3. Calculation of the torsional resistance factor J

4. Calculation of the extreme fiber distances from neutral axis to all angle tip points. The worksheet is protected but without a password

Calculation Reference
AISC 13th Edition