For the parts I ended up checking the scatter appeared to be on the order of 0.1% for parts with measurably consistent dimensions. Accounting for machining variations took the scatter to about 0.4%. However, I can't claim to have checked this fact exhaustively across material lots. Once I got a read on what the nominal density should be, it was close enough to get me to my end goal...I just got burned by trusting a number that I hadn't even tried to verify up front and now consider the possibility that one of the resources I tend to trust for up front estimates may be far enough off to cause a similar problem in future.
Chris Masterson Toyota Racing Development
"Mally, Carl" Sent by: xansys-bounces_at_xansys.org 05/06/2008 11:28 AM Please respond to ANSYS User Discussion List
To "ANSYS User Discussion List" cc
Subject Re: [Xansys] [XANSYS][Other] GKH modulus
Chris What is the data scatter. It changed my view of material properties when I had to work with the test labs and got access to the raw tensile pull data. All data sheets are averages of several pulls. They may not even reflect lot to lot variation. I experienced this a lot with formability for precision stamping in a previous life. Even the best material had greater than 1 percent variation lot to lot. Carl Mally Senior Applications Engineer Centro Inc. 950 North Bend Drive North Liberty, IA 52317
-----Original Message----- From: xansys-bounces_at_xansys.org [mailto:xansys-bounces_at_xansys.org] On Behalf Of Chris_Masterson_at_Toyota.com Sent: Tuesday, May 06, 2008 12:12 PM To: ANSYS User Discussion List Subject: Re: [Xansys] [XANSYS][Other] GKH modulus
Incidentally, I just happened to check another steel grade on Matweb for which I already have a data sheet from the manufacturer. The density listed on Matweb is different from what the manufacturers data sheet claims. The difference is only about 1% but that is sufficient to cause problems when trying to design as close as possible to minimum weight rules. Leaves me wondering how many other times I have trusted Matweb too much in the absence of proper vendor datasheets.
Regards, Chris Masterson Toyota Racing Development
rick.fischer_at_emersonnetworkpower.com Sent by: xansys-bounces_at_xansys.org 05/06/2008 06:14 AM Please respond to ANSYS User Discussion List
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Subject Re: [Xansys] [XANSYS][Other] GKH modulus
I dont see Young's Modulus listed, but there is a data sheet on page 28.
The composition is listed a the top of the page. Try and match that up with another material on MatWeb. It's a fair bet that similar chemistries
will result in similar structure and similar Young's Modulus.
Rick Fischer Principal Engineer Emerson Network Power
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