# Flat tension bar with a U-shaped notch at one side

## Values for calculation

$P$ $\mathrm{N}$
$r$ $\mathrm{mm}$
$t$ $\mathrm{mm}$
$H$ $\mathrm{mm}$
$h$ $\mathrm{mm}$

## Calculation

### Coefficient $C_1$

$\text{if }\ 0.5\le t/r\le 2.0$
$$C_1=0.907+2.125\cdot\sqrt{t/r}+0.023\cdot t/r$$
$\text{else}$
$$C_1=0.953+2.136\cdot\sqrt{t/r}-0.005\cdot t/r$$

### Coefficient $C_2$

$\text{if }\ 0.5\le t/r\le 2.0$
$$C_2=0.710-11.289\cdot\sqrt{t/r}+1.708\cdot t/r$$
$\text{else}$
$$C_2=-3.255-6.281\cdot\sqrt{t/r}+0.068\cdot t/r$$

### Coefficient $C_3$

$\text{if }\ 0.1\le t/r\le 2.0$
$$C_3=-0.672+18.754\cdot\sqrt{t/r}-4.046\cdot t/r$$
$\text{else}$
$$C_3=8.203+6.893\cdot\sqrt{t/r}+0.064\cdot t/r$$

### Coefficient $C_4$

$\text{if }\ 0.1\le t/r\le 2.0$
$$C_4=0.175-9.759\cdot\sqrt{t/r}+2.365\cdot t/r$$
$\text{else}$
$$C_4=-4.851-2.793\cdot\sqrt{t/r}-0.128\cdot t/r$$

### Stress concentration factor with the nominal stress based on net area

$$K_{tn}=C_1+C_2\cdot\left(\cfrac{t}{H}\right)+C_3\cdot\left(\cfrac{t}{H}\right)^2+C_4\cdot\left(\cfrac{t}{H}\right)^3$$

### Nominal or reference normal stress

$$σ_{nom}=\cfrac{P}{h\cdot\left(H-t\right)}$$

### Maximum normal stress

$$σ_{max}=K_{tn}\cdot σ_{nom}$$

### Normal stress

$$σ=\cfrac{P}{h\cdot H}$$

### Stress concentration factor with the nominal stress based on gross area

$$K_{tg}=\cfrac{σ_{max}}{σ}$$