FD&E Standard Files

F.D.& E. SAE Standard Files (Proposal)

F.A. Conle
member of Fatigue Design & Evaluation Committee of SAE
Dec. 7, 1999
Web page: https://fde.uwaterloo.ca/Fde/README_stdfiles.html

Introduction

The Fatigue Design and Evaluation Committee of the SAE is experimenting with standard file formats for various types of fatigue data. The purpose of standard fatigue files is to allow easy interchange of data between individuals, and, probably more importantly, between individuals and programs. It would be useful for students or others to be able to submit test data files to a website for processing; or it they are ambitious, to tranform their research into new algorithms that can process anyone's standard files. The results would generate significant efficiencies for all of us involved in the exchange and processing of fatigue information. In particular it would help to alleviate the eternally vexing problem of file conversions. Many many months of effort are wasted each year performing data manipulations and file conversion, when our time would be better spent on research of improved methods.

Examples of Standard Files

In the present case, a standard file implies one of the new SAE/F.D.& E. standard files for strain-life data, stress-strain data, or rainflow data. Each has a specific, yet simple, format specified by FD&E or SAE. The user can either create his own file with any text editor, or in many cases the data may originate from a testing center or other supplier.
Here are some examples of standard files:

SAE Strain-Life (standard), txt
FDE Strain-Stress (proposed), txt
FDE ASCII text load history (proposed), txt Not implemented. Use gnuplot instead.
SAE Rainflow (standard), txt

Note that each file is a simple text file. In each file there are comment lines, which begin with a # in column_1, and data lines, which are simply numbers. Some of the comment lines have a special meaning and are in a form:

#Date= 1999 December 7

These are "picked-up" by software reading the file and can be used to tell the software what the file type is, what processing is required, etc.

Many users might download all the available GNU licensed fatgiue software into their own machines, compile the source (helps to prevent viruses) (viri?) and then run the codes over their own locally located standard files. Many more users would probably not wish to download and compile the software, and would prefer to submit their files to some remote web server on their company web, or to a university for processing. Such a submission can be easily done by adding a text "header" to the front of the file, and a short "trailer" to the bottom of the file. The file is then loaded or opened by the user's Netscape browser, and with a "click" on the header button, the file is transmitted for processing. If all goes well, a page will be returned to the user's browser, that contains the required graphs or calculation results. Please read the file on Calculation Wrappers if you want more information on how to use this processing feature.

Comments to : conle(a)mecheng1*uwaterloo*ca
Last update Dec. 7, 1999.