# Homework Help: Calculate maximum allowable stress

1. Sep 6, 2011

### cd19

1. A decision has been made to make a plate out of an advanced engineering material ceramic that has better high temperature and wear properties than alloys. The plate must withstand a tensile load of 177.92kN. The part will be non-destructively tested to ensure that no flaws are present that might cause failure. A company offers non-destructive testing methods using x-ray radiology that can detect flaws larger than 0.05 cm. Assume Y=1.0. Determine the minimum thickness for a 7.5mm wide plate made of sialon (Kic = 9.9 Mpa$\sqrt{}m$) . Also calculate the maximum allowable design stress.

2. Kic = Y*$\sigma$*sqrt{$\pi$*a}

$\sigma$ allowable = FORCE/AREA

3. I just don't see how to factor in the 'thickness' into my calculations and so i cannot begin with my calculations. Can someone help me with this please.

2. Sep 6, 2011