The following notes have been formated nicely in www.lstc.com/sdb/327 ===================================================================== Definition of a consistent system of units (required for LS-DYNA): 1 force unit = 1 mass unit * 1 acceleration unit 1 acceleration unit = 1 length unit / (1 time unit)^2 The following table provides examples of consistent systems of units. As points of reference, the mass density and Young's Modulus of steel are provided in each system of units. "GRAVITY" is gravitational acceleration. MASS LENGTH TIME FORCE STRESS ENERGY DENSITY YOUNG's 35 mph GRAVITY 56.33 kph kg m s N Pa Joule 7.83e+3 2.07e+11 15.65 9.806 kg m ms MN MPa 7.83e+3 2.07e+05 0.01565 9.806e-06 kg cm s 1.e-02N 7.83e-3 2.07e+09 1.56e+03 9.806e+02 kg cm ms 1.e+04N 7.83e-3 2.07e+03 1.56 9.806e-04 kg cm us 1.e+10N 7.83e-3 2.07e-03 1.56e-03 9.806e-10 kg mm ms kN GPa kN-mm 7.83e-6 2.07e+02 15.65 9.806e-03 g cm s dyne dy/cm2 erg 7.83e+0 2.07e+12 1.56e+03 9.806e+02 g cm us 1.e+07N Mbar 1.e7Ncm 7.83e+0 2.07e+00 1.56e-03 9.806e-10 g mm s 1.e-06N Pa 7.83e-3 2.07e+11 1.56e+04 9.806e+03 g mm ms N MPa N-mm 7.83e-3 2.07e+05 15.65 9.806e-03 tonne mm s N MPa N-mm 7.83e-9 2.07e+05 1.56e+04 9.806e+03 kg mm s mN kPa 7.83e-6 2.07e+08 9.806e+03 g cm ms 1e5 Pa 7.83e+0 2.07e+06 9.806e-04 mg mm us kN GPa 7.83 2.07e+02 1.56e-02 9.806e-09 ng um us uN MPa 2.07e+05 ng nm us nN GPa 2.07e+02 kgfs2/mm mm s kgf kgf/mm2 kgf-mm 7.98e-10 2.11e+04 1.56e+04 9.806e+03 ------------------------------------------------------------------------------------------ lbfs2/in in s lbf psi lbf-in 7.33e-4 3.00e+07 6.16e+02 386 slug ft s lbf psf lbf-ft 1.52e+1 4.32e+09 51.33 32.17 1 slug = 1 lbf*s^2/ft 1 kgf = 1 kg * 9.806 N/kg = 9.806 N 1 kgf*s^2/mm = 9806 kg Prefixes: k = kilo 10E3 M = mega 10E6 G = giga 10E9 m = milli 10E-3 u = micro 10E-6 n = nano 10E-9