# Overall convention of signs of normal forces and stresses

Positive value = Tension

Negative value = Compression

Only exception in Subsoils (contact stresses sigma,z):

Positive values = Compression

Negative values = Tension

# 2D members

## 1) Basic magnitudes = characteristic values

### Bending (plates, shells)

Bending moments mx, my

Torsion moment mxy

Shear forces qx, qy (= vx, vy)

### Membrane effects (walls, shells)

Membrane forces nx, ny

Shear force qxy (= nxy)

Basic stresses on 2D

## 2) Principal magnitudes

The principal magnitudes give the results according to the axes of the directions of the largest stresses (principal directions). These directions are defined with the help of the Mohr’s circle:

Principal moments – plate

Principal forces – wall

Principal stresses on 2D

## 3) Dimensional magnitudes = design values

To derive the dimensional magnitudes from the basic magnitudes, formulas from the Eurocode are used.

Dimensional moments from EC2 – plate

Dimensional moments, classical method – plate

Dimensional forces from EC2 – wall

Dimensional forces, classical method – wall