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.

NOTE: All section properties are taken with respect to the global Z and Y axis. This axis is equivalent to the principal axis for all shapes other than angle sections. These functions do not produce results relative to the principal axes for angle sections.

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
• Solid Rectangular Sections
• Solid Circular 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.

NOTE: All section properties are taken with respect to the global Z and Y axis. The principal axes for an angle section are generally not equivalent to the global Z and Y axis, meaning the function results for angle sections are not about the principal axes.

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);

SolidRectangleProperties = (d, b)

Calculates the section properties for a custom Solid Rectangle section.

Parameter	Type	Description
d	number	Total depth of section
b	number	Top width of section

Returns: object - Object containing section properties.

Example Code

In the calculate.js (or util) file.

const sectionProps = SectionProps;

let sect = sectionProps.SolidRectangleProperties(d_input, b_input);

SolidCircleProperties = (b)

Calculates the section properties for a custom Solid Circle section.

Parameter	Type	Description
b	number	Outer diameter of section

Returns: object - Object containing section properties.

Example Code

In the calculate.js (or util) file.

const sectionProps = SectionProps;

let sect = sectionProps.SolidCircleProperties (b_input);