Gable Frame
BMD
Calculator
TWO-HINGED SYMMETRIC PORTAL FRAME · GRAVITY LOADS · FORCE METHOD
SBC 2018 · LRFD
Frame Parameters
Span (L)
m
Eave Height (h)
m
Roof Slope
%
Loads (Gravity)
Dead Load (D)
kN/m
Live Load (L)
kN/m
Derived Geometry
Ridge Rise (f)
—
Ridge Height
—
Rafter Length
—
Slope Angle
—
CALCULATE BMD
Bending Moment Diagram
POSITIVE MOMENT (Sagging)
NEGATIVE MOMENT (Hogging)
FRAME MEMBER
APPLIED LOAD
Structural Results
Horizontal Thrust (H)
—
at both base hinges
Vertical Reaction (V)
—
each support
Moment at Eave
—
frame corner (hogging)
Moment at Ridge
—
peak (sagging)
Max Rafter Moment
—
location along rafter
Distance from Ridge to Zero Moment
—
measured along inclined rafter from ridge toward eave
SBC 2018 Load Combinations
Combination
wu (kN/m)
H (kN)
M_eave (kN·m)
M_ridge (kN·m)
M_max (kN·m)
x₀ from Eave — inclined (m)
Status
Analysis Assumptions
Two-hinged symmetric gable frame
Uniform EI throughout all members
Loads applied per horizontal meter
Force method — H as redundant
Second-order effects ignored
SBC 2018 LRFD combinations
Pinned (hinged) column bases
Rigid eave and ridge connections