What is a P-M interaction diagram?

A P-M diagram shows all combinations of axial force P and moment M that a cross-section can resist simultaneously at its limit state.

How is the P-M curve used in design?

The applied load point (Pu, Mu) must fall inside the interaction curve; if outside, the section is overstressed and must be enlarged.

Beam-Column P-M Interaction Curve Calculator

Calculate the axial force-moment (P-M) interaction diagram for beam-columns. Determine capacity at combined axial and bending loads per AISC and ACI design codes.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How to Use

Enter the values for the scenario you are assessing. Calculate the axial force-moment (P-M) interaction diagram for beam-columns. Determine capacity at combined axial and bending loads per AISC and ACI design codes. Use the p-m interaction curve result to inform your calculation.

Beam-Column P-M Interaction Curve Calculator

How to Use

Frequently Asked Questions

What is a P-M interaction diagram?

How is the P-M curve used in design?