Truss Force Calculator
Calculate member forces for one ideal symmetric three-member triangular truss under a centered vertical joint load.
A QUICK WALKTHROUGH
How to use this tool
- Idealized static planar pin-jointed model only: a symmetric triangle, horizontal base, centered vertical load at the apex, pin at the left base joint, roller at the right base joint, and axial-force-only members. It excludes self-weight, other loads, joint offsets, deformation, member stiffness, buckling, connection capacity, material strength, and safety factors. This is a hand-calculation aid, not structural design certification.
- θ = atan(2h/L); diagonal force = P ÷ (2 sin θ); bottom-chord force = P ÷ (2 tan θ); each vertical reaction = P ÷ 2.
- Inputs and calculations stay in this browser.
Formula
θ = atan(2h/L); diagonal force = P ÷ (2 sin θ); bottom-chord force = P ÷ (2 tan θ); each vertical reaction = P ÷ 2.
Assumptions and limits
Idealized static planar pin-jointed model only: a symmetric triangle, horizontal base, centered vertical load at the apex, pin at the left base joint, roller at the right base joint, and axial-force-only members. It excludes self-weight, other loads, joint offsets, deformation, member stiffness, buckling, connection capacity, material strength, and safety factors. This is a hand-calculation aid, not structural design certification.
Local processing
Inputs and calculations stay in this browser.
GOOD TO KNOW
Common questions
What load cases does this cover?
Only a symmetric three-member triangle with a centered vertical apex load, a left pin, and a right roller; other loads and support layouts are outside scope.
Is this a structural design certification?
No. It is an idealized hand-calculation aid and excludes member strength, buckling, connections, self-weight, deformation, and safety factors.