Tsai-Wu Failure Index 1

[ReaferRows]

I have to do a Montecarlo analysis of a sandwich composit;
When calculating tsai-wu FI with S T R E S S E S I N L A Y E R E D C O M P O S I T E E L E M E N T S ( Q U A D 4 ) in Patran they differ from : F A I L U R E I N D I C E S F O R L A Y E R E D C O M P O S I T E E L E M E N T S ( Q U A D 4 ) already calculated by Patran; Why??

 

[SWComposites]

Maybe Patran uses averaged nodal stresses and Nastran uses element stresses?? Have you read the documentation?

By the way, Tsai-Wu criteria does not accurately predict laminate strength. Not even close. See previous discussions in the Composite Engineering forum .