Calculator · Structural Mechanics
Normal Stress Calculator
Average normal stress on a cross-section carrying an internal axial force. The result is the stress averaged over the whole area, so it is valid away from holes, shoulders and the points where the load is introduced.
Inputs
Positive is tension, negative is compression.
N is the internal axial force from the right free body, N(x) = Σ Fx for every load beyond the cut. N > 0 is tension, N < 0 is compression.
Results
| Internal axial force N | 25000 N |
|---|---|
| Area A | 5.0000e-4 m² |
| Normal stress σ = N/A | 50 MPa |
| Sense | tension |
Technical reference
σ = N / A
- N
- internal axial force on the cut, tension positive[N]
- A
- cross-sectional area resisting the force[m²]
- σ
- average normal stress on the section[Pa]
This is the AVERAGE stress over the section. It is the actual stress only where the distribution is uniform: a prismatic member, loaded through the centroid, away from load introduction points and geometric discontinuities.
Near a hole, notch, shoulder or concentrated load the peak stress is higher than N/A by a stress-concentration factor that this relation does not include.
N is the internal force on the cut, not the applied load. For a member with several loads along its length, resolve N first — the Axial Members Lab does that interval by interval.
Assumptions
- · Prismatic member, load applied along the centroidal axis, so the section carries no bending.
- · Linear-elastic, homogeneous and isotropic material.
- · Section far enough from load introduction and discontinuities for Saint-Venant's principle to apply.
Open in the Lab
N and A carry over unchanged. Length (1 m) and modulus (200 GPa) are placeholders the stress σ = N/A does not depend on — edit them in the Lab.