# Problem 919 | Additional Axial Compression Load for the Section to Carry No Tensile Stress

**Problem 919**

From the data in Prob. 918, what additional load applied at the centroid is necessary so that no tensile stress will exist anywhere on the cross-section?

**Solution 919**

Relevant data extracted from Solution 918
$\text{Area} = 60 ~ \text{in.}^2$

$\sigma_B = 320 - \dfrac{P_2}{60} = 0$
$\sigma_A = -480 ~ \text{psi}$
$\sigma_A = -480 - 320 = -800 ~ \text{psi}$

The largest tensile stress is at corner *B*

$\sigma_B = 320 ~ \text{psi}$

Additional compression force *P*_{2} for zero stress at corner *B*

$P_2 = 19,200 ~ \text{lbs}$ ← *answer*

Stress at each corner from Solution 918

$\sigma_B = 320 ~ \text{psi}$

$\sigma_C = 80 ~ \text{psi}$

$\sigma_D = -720 ~ \text{psi}$

Stress at each corner due to additional stress σ_{2} = -320 psi.

$\sigma_B = 320 - 320 = 0$

$\sigma_C = 80 - 320 = -240 ~ \text{psi}$

$\sigma_D = -720 - 320 = -1040 ~ \text{psi}$

See figure above.

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