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NX Nastran Nonlinear problem

Dear Nastran users,

anybody know where I find out documentation about the following Nastran error?

 
 
============================================================
Information listing created by :  Dell
Date                           :  19/02/2016 14:51:00
Current work part              :  C:\Users\Dell\OneDrive\oppermann\Screws Model\FEM\A-SpineType_sim1.sim
Node name                      :  optimusprime
============================================================
 

NASTRAN Msg:      ***WARNING: First non-zero strain value set to 5.422110552764 in
TABLES1= 1 used in MATS1= 4.
                              ((Yield stress)/(Youngs modulus))
NASTRAN Msg:      ***ERROR: Input strain value 2.1900000000000E-02 in TABLES1= 1 used in
MATS1= 4
                            must be greater than first non-zero strain value
5.422110552764 .
NASTRAN Msg:  *** FATAL ERROR: PROCESSING OF NASTRAN DATA FOR SOL 601 FAILED.
              *** ADVANCED NONLINEAR EXIT CODE 0 ***
NASTRAN Msg:  ^^^ USER FATAL MESSAGE 
              ^^^ ERROR IN ADVANCED NONLINEAR MODULE          0
 

Total messages: 1 WARNING and 3 FATALS

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My analysis is axysimmetric model(pull out screw idealization). Please, find attached attached this files.

 

I appreciate you help.

Best Regards

Alex Araujo

3 REPLIES

Re: NX Nastran Nonlinear problem

Phenom
Phenom

double check your stress-strain definition (table)

Production: NX9.0.3.4, NX10.0.2.6
Development: VB.NET (amateur level !)

Re: NX Nastran Nonlinear problem

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear Alex,

You have two errors:

  1. The Young modulus of "Cortical Bone_new" has a value of "19900", wrong!, the default units of the template in NX AdvSim are mN/mm2 (KPa), not MPa, then you should enter the correct value as 19900e3 mN/mm2 (or change the units to MPa).
  2. The first point of the stress-strain curve with non-zero value should be exactly the value for the YIELD-STRESS vs strain, then to compute the strain you should enter Epsilon = SIGYLD/Ex (ie, "107.9 MPa, 107.9/19900e3"), if not NX NASTRAN will complaint.
  3. Repeat the same for the other material "Trabecular Bone_new", make sure to enter the first non-zero point of your stress-strain curve correctly as "84.9 MPa, 84.9/18e6", OK?.

Best regards,

Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: NX Nastran Nonlinear problem

Thanks Blas for your support. I will test this on Monday.