Re: dynamic stress analysis .

From: <Christopher>
Date: Wed Dec 29 2004 - 14:39:00 EST

On Dec 28, 2004, at 11:37 PM, Umapathy, A wrote:

> For Static loading the Design factor of safety: 60% of Yield stress is
> considered and for dynamic loading it would be 35% to have a life
> of 1 million cycles or more.

This is a bit over simplified becasue it depends greatly on the type of construction and the service. The 60% number applies to AISC Code design for working stress; oit's different for LRFD rules becasue the design loads are factored upward. Neither figure applies to ASME piping or pressure vessel code rules.

And just for cultural value, the safety factor is always greater than 1: it's the limiting stress or load divided by the maximum allowable stress or load and it's not necessarily based on yield stress.

Christopher Wright P.E. |"They couldn't hit an elephant at <a href="/group/PipingDesign/post?postID=2dPr4i4Qm_2w_ayM_xdw9hSRj7C2S5cmuKa9TcrNqYxHnh-fHN2FpbX88F1s3kldtmF0AL8Z38NjC1eMkA">chrisw@skypoint.com</a> | this distance" (last words of Gen.

...................................| John Sedgwick, Spotsylvania 1864)

<a href="http://www.skypoint.com/~chrisw/">http://www.skypoint.com/~chrisw/</a> Received on Wed Dec 29 14:39:00 2004