Sixma Purlin Design

Input Parameters

SECTION · GEOMETRY · BRACING · LOADING

SI UNITS · ASCE 7-05 ASD

① PURLIN SECTION

Section Type

Depth d (mm)

Flange b (mm)

Thickness t (mm)

Lip c (mm)

Corner R (mm)

Material Grade

Area A

—

mm²

Ixx

—

cm⁴

—

cm³

—

kN·m

② SPAN · SUPPORT · BRACING

A · GEOMETRY

Purlin Spacing (m)

No. of Spans: 1

Left Support

Right Support

B · SPAN LENGTHS & INTERIOR SUPPORTS

C · SAGROD / BRIDGING — LTB BRACING

Gov. Lb: —

AUTO — EQUAL SPACING

Type

No./Span

MANUAL — EXACT POSITION

Type

x (m)

✕ Sagrod ⌀12 ◆ C75×1.0 ◆ C100×1.5 — Lb shown on beam

SECTION PREVIEW

J St.Venant

—

mm⁴

Cw Warping

—

mm⁶

③ LOADS ASCE 7-05 ASD · kN/m²

ROOF PURLIN

D Dead

Roofing + structure (SW auto)

L Live

Maintenance / access

C Collateral

Services / ceilings

W↑ Wind Uplift

Acts upward · −ve gravity

δ Defl. Limit

Serviceability check

θ Roof Slope

degrees

LOAD SUMMARY

—

⊕ Additional Point & Distributed Loads

TypeCaseMagnitudeSpanPosition / Range

Beam Diagrams

REACTIONS · BMD · SFD · DEFLECTION — ASD GOVERNING COMBO

—

SCALE TEXT

VIEW COMBO:

Max M (ASD)

—

kN·m

Max V (ASD)

—

Max δ

—

δ Limit

—

SPAN VALUES TABLE

x (m)	Span	M (kN·m)	V (kN)	δ (mm)
Run analysis

Load Combinations

ASCE 7-05 ASD — SECTION 2.4 COMBINATIONS

ASD

APPLIED LOADS (per purlin, kN/m)

ASD LOAD COMBINATIONS (ASCE 7-05 §2.4)

COMBO	EXPRESSION	w (kN/m)	M_max (kN·m)	V_max (kN)	GOVERNS

GOVERNING COMBINATION SUMMARY

Run analysis to populate.

Section Properties

GROSS SECTION · TORSIONAL · EFFECTIVE

CROSS-SECTION

GROSS SECTION PROPERTIES

PROPERTY	VALUE	UNIT

STANDARD SECTION LIBRARY — click to load

DSM Buckling Analysis

DIRECT STRENGTH METHOD · AISI S100 APPENDIX 1 · pyCUFSM PLATE THEORY

AWAITING

FSM SIGNATURE CURVE — M_cr/M_y vs HALF-WAVELENGTH

Plate theory · Rotational spring model

── Signature curve ── My ▼ Local (Mol) ▲ Distortional (Mod) ● Global LTB (Mone)

BRACING LAYOUT & UNBRACED SEGMENTS

UNBRACED

—

Mol — Local Buckling

—

kN·m

Lcr = — mm · Governs: —

Mod — Distortional

—

kN·m

Lcr = — mm

Mone — Global LTB

—

kN·m

Lb = — m · Cb = 1.0

DSM NOMINAL STRENGTHS (AISI S100 App.1)

LIMIT STATE	λ	Mn (kN·m)	Ωb	Mn/Ωb (kN·m)	REGIME

DSM GOVERNING STRENGTH

Local · Mnl/Ωb

—

Distortional · Mnd/Ωb

—

Global LTB · Mne/Ωb

—

Governing DSM Allowable

—

kN·m [—]

DSM CALCULATION LOG

—

Unity Check

DEMAND/CAPACITY — AISI S100 ASD · ASCE 7-05 LOAD COMBINATIONS

AWAITING

GOVERNING UNITY RATIO

—

0 ─────────────────── 1.0

ALL LOAD COMBINATIONS — BENDING CHECK — Critical combo at each check point

x (m)	Location	Gov. Combo	M* (kN·m)	Ma (kN·m)	UC_M	Status

ALL SHEAR CHECK — Critical combo at each check point

x (m)	Location	Gov. Combo	V* (kN)	Va (kN)	UC_V	Status

Bending UC (gov.)

—

Shear UC (gov.)

—

Deflection UC (SLS)

—

DESIGN NOTES

Run analysis.

▌ CRITICAL SECTION ENVELOPE — Capacity vs Demand Along Beam Demand vs capacity at all mandatory check points — all load combinations

x (m)	Location	EI	Section	Combo	M* (kN·m)	V* (kN)	Ma (kN·m)	Va (kN)	UC_M	UC_V	UC_H2	UC_gov

Calculation Report

ENGINEERING SUMMARY SHEET

SIXMA — PURLIN DESIGN CALCULATION SHEET

Run analysis to generate.