nastran_logosNASTRAN 101

Outline

  • Introduction
  • File Structure
  • Executive Control
  • Bulk Data
  • Element Types
  • Element Examples
  • Output Files

What is a Finite Element ‘Solver’?

  • NASTRAN is one of many available finite element analysis (FEA) solvers
    – Other solvers at Quartus: ABAQUS, ANSYS, LS-DYNA
  • What does a solver do? (the short answer) 
    • User provides input in the form of a text file
    • Solver reads the text file and performs analysis
    • The solver generates output files with analysis results
  • How does the user make the input text file? 
    • Models are created and input files exported using FEA pre/post processing software
    • Various Pre/Post Processors available

What is NASTRAN?

Nastran is a powerful finite element analysis program that is used widely in the aerospace and automotive industries

  • Industry standard finite element code originally developed for NASA by MSC (1960s)
  • Today there are many flavors (or versions) of Nastran MSC, NX, etc.

Nastran at Quartus

  • Primary program used for finite element analysis
  • Used extensively to perform static, buckling, and dynamic analyses of structures
  • Quartus has licenses for both NX/Nastran and MSC Nastran
    • Largely the same (basic functionality)
    • Some small differences and enhancements

What Units Does NASTRAN Use?

  • NASTRAN does not have a defined unit system
  • The user must be careful to maintain consistent units Units must be consistent such that units satisfy F= ma Examples for English and SI units are shown below:

units

Note: for English units (in, lbf, sec), the unit of mass is a ‘slinch’ (lbf-sec2/in), not a pound (lb). A slinch is the ‘inch version of a slug’. To convert from pounds to slinches you divide by the acceleration of gravity (386.1 in/sec^2)