Quick Design Section Properties

The Quick Design Section Properties library has been developed to standardize the creation of custom steel cross-sections in quick design calculations. These functions take the dimensions of a custom section and return a section object with commonly used section properties. The section object mimics the format of a section pulled from the SkyCiv database using the await Database.getSection() function. The sample return format is outlined below.

var sect = {

"shape": "ibeam",

"dimensions": {

"BFt":

"BFw":

"TFt":

"TFw":

"Wt":

"h":

"r":

},

"results": {

"A": //Gross section area

"Cy": //Centroid taken from the bottom of section

"Cz": //Centroid taken from the left side of section

"Iyp": //Moment of Inertia about y axis

"Izp": //Moment of Inertia about z axis

"ry": //Radius of Gyration about y axis

"rz": //Radius of Gyration about z axis

"Zyp_top": //Elastic section modulus about y axis (centroid is taken from right side of section)

"Zyp_btm": //Elastic section modulus about y axis (centroid is taken from left side of section)

"Zzp_top": //Elastic section modulus when about z axis (centroid is taken from top of section)

"Zzp_btm": //Elastic section modulus when about z axis (centroid is taken from btm of section)

"PNAy": //Plastic neutral axis location taken from btm side of section

"PNAz": //Plastic neutral axis location taken from left side of section

"Syp": //Plastic section modulus about y axis

"Szp": //Plastic section modulus about z axis

"J": //Torsion constant (Not available for hat sections)

}

}

Installation

You can install the section props library as follows:

const sectionProps = SectionProps;

Supported Sections

• I Sections
• T Sections
• Channel Sections
• Angle Sections
• Rectangular Hollow Sections
• Circular Hollow Sections
• Hat Sections

Functions

ISectionProperties(d, b, t_f, t_w)

Calculates the section properties for a custom I section.

Parameter	Type	Description
d	number	Total section depth
b	number	Total flange width
t_f	number	Section flange thickness
t_w	number	Section web thickness

Returns: object - Object containing section properties.

Example Code

In the calculate.js (or util) file.

const sectionProps = SectionProps;

let sect = sectionProps.ISectionProperties(d_input, b_input, t_f_input, t_w_input);

TSectionProperties(d, b, t_f, t_w)

Calculates the section properties for a custom T section.

Parameter	Type	Description
d	number	Total section depth
b	number	Total flange width
t_f	number	Section flange thickness
t_w	number	Section web thickness

Returns: object - Object containing section properties.

Example Code

In the calculate.js (or util) file.

const sectionProps = SectionProps;

let sect = sectionProps.TSectionProperties(d_input, b_input, t_f_input, t_w_input);

PFCSectionProperties(d, b, t_f, t_w)

Calculates the section properties for a custom Channel section.

Parameter	Type	Description
d	number	Total section depth
b	number	Total flange width
t_f	number	Section flange thickness
t_w	number	Section web thickness

Returns: object - Object containing section properties.

Example Code

In the calculate.js (or util) file.

const sectionProps = SectionProps;

let sect = sectionProps.PFCSectionProperties(d_input, b_input, t_f_input, t_w_input);

AngleSectionProperties(d, b, t_f, t_w)

Calculates the section properties for a custom Angle section.

Parameter	Type	Description
d	number	Vertical leg length
b	number	Horizontal leg length
t_f	number	Horizontal leg thickness
t_w	number	Vertical leg thickness

Returns: object - Object containing section properties.

Example Code

In the calculate.js (or util) file.

const sectionProps = SectionProps;

let sect = sectionProps.AngleSectionProperties(d_input, b_input, t_f_input, t_w_input);

RHSSectionProperties(d, b, t_f, t_w)

Calculates the section properties for a custom Rectangular Hollow Section.

Parameter	Type	Description
d	number	Total section height
b	number	Total section width
t_f	number	Horizontal (top) wall thickness
t_w	number	Vertical (side) wall thickness

Returns: object - Object containing section properties.

Example Code

In the calculate.js (or util) file.

const sectionProps = SectionProps;

let sect = sectionProps.RHSSectionProperties(d_input, b_input, t_f_input, t_w_input);

CHSSectionProperties(d, t_f)

Calculates the section properties for a custom Circular Hollow Section.

Parameter	Type	Description
d	number	Outer diameter
t_f	number	Wall thickness

Returns: object - Object containing section properties.

Example Code

In the calculate.js (or util) file.

const sectionProps = SectionProps;

let sect = sectionProps.CHSSectionProperties(d_input, t_f_input);

HatSectionProperties = (d, b_1, b_2, t_f)

Calculates the section properties for a custom Hat section.

Parameter	Type	Description
d	number	Total depth of section
b_1	number	Top flange width
b_2	number	Btm leg width
t_f	number	Thickness of section

Returns: object - Object containing section properties. Note, this function does not currently calculate J or Iw values for a hat section.

Example Code

In the calculate.js (or util) file.

const sectionProps = SectionProps;

let sect = sectionProps.HatSectionProperties(d_input, b_1_input, b_2_input, t_f_input);