Calculate maximum allowable stress


by cd19
Tags: allowable, maximum, stress
cd19
cd19 is offline
#1
Sep6-11, 07:28 AM
P: 52
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[itex]\sqrt{}m[/itex]) . Also calculate the maximum allowable design stress.



2. Kic = Y*[itex]\sigma[/itex]*sqrt{[itex]\pi[/itex]*a}

[itex]\sigma[/itex] 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.
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edgepflow
edgepflow is offline
#2
Sep6-11, 02:53 PM
P: 688
Stress in a plate is a different than the direct tension formula you listed.

Have a look at:

http://www.efunda.com/formulae/solid...study_list.cfm


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