5.2.2 Hoffmann

    (syntax)

YIELD

HOFMAN specifies that the Hoffmann criterion must be used.

YLDOPT

optnam activates an option for the yield criterion. MATAXI for yield stresses $\sigma_{{\mathrm{y}}}^{}$ defined in principal anisotropic directions. OFFAXI for yield stresses $\sigma_{{\mathrm{y}}}^{}$ defined with a 45° off-axis tensile test.

YLDSIG

sigy are the yield stresses $\boldsymbol\sigma$_y .

The type and number of stresses to be input depends on the option and the element family as outlined in Table 5.2.

Table 5.2: YIELD STRESSES HOFFMANN

Option	Element fam.	sigy
MATAXI	pl. stress	$\sigma_{{\mathrm{y} . xx_{t}}}^{}$  $\sigma_{{\mathrm{y} . yy_{c}}}^{}$  $\sigma_{{\mathrm{y} . yy_{t}}}^{}$  $\sigma_{{\mathrm{y} . yy_{c}}}^{}$  $\sigma_{{\mathrm{y} . zz_{t}}}^{}$  $\sigma_{{\mathrm{y} . zz_{c}}}^{}$  $\sigma_{{\mathrm{y} . xy}}^{}$
	pl. strain
	axisymm.
	solid	$\sigma_{{\mathrm{y} . xx_{t}}}^{}$  $\sigma_{{\mathrm{y} . xx_{c}}}^{}$  $\sigma_{{\mathrm{y} . yy_{t}}}^{}$  $\sigma_{{\mathrm{y} . yy_{c}}}^{}$$\sigma_{{\mathrm{y} . zz_{t}}}^{}$  $\sigma_{{\mathrm{y} . zz_{c}}}^{}$  $\sigma_{{\mathrm{y} . xy}}^{}$  $\sigma_{{\mathrm{y} . yz}}^{}$  $\sigma_{{\mathrm{y} . zx}}^{}$
	shell
OFFAXI	pl. stress	$\sigma_{{\mathrm{y} . xx_{t}}}^{}$  $\sigma_{{\mathrm{y} . xx_{c}}}^{}$  $\sigma_{{\mathrm{y} . yy_{t}}}^{}$  $\sigma_{{\mathrm{y} . yy_{c}}}^{}$  $\sigma_{{\mathrm{y} . 45\text{\textdegree}}}^{}$  $\sigma_{{\mathrm{y} . xy}}^{}$
	pl. strain
	axisymm.
	solid	$\sigma_{{\mathrm{y} . xx_{t}}}^{}$  $\sigma_{{\mathrm{y} . xx_{c}}}^{}$  $\sigma_{{\mathrm{y} . yy_{t}}}^{}$  $\sigma_{{\mathrm{y} . yy_{c}}}^{}$  $\sigma_{{\mathrm{y} . 45\text{\textdegree}}}^{}$  $\sigma_{{\mathrm{y} . xy}}^{}$  $\sigma_{{\mathrm{y} . yz}}^{}$  $\sigma_{{\mathrm{y} . zx}}^{}$
	shell

    (file.dat)

'MATERI'
  1   YOUNG    1.0E8
      POISON   0.3
      YIELD    HOFMAN
      YLDOPT   OFFAXI
      YLDSIG   0.5E2 1.0E3 0.5E2 1.0E3 0.25E3
               0.577E3 0.577E3 0.577E3
'GEOMET'
  1   XAXIS    1.0  0.0  0.0
  2   XAXIS    1.0  0.0  0.0