Hill Criterion

Calculates the ply failure index according to the Hill (Tsai-Hill) theory.

${\text{F}}_{\text{index}}=\frac{{\text{σ}}_1^2}{{\text{X}}^2}-\frac{{\text{σ}}_1{\text{*σ}}_2}{{\text{X}}^2}+\frac{{\text{σ}}_2^2}{{\text{Y}}^2}+\frac{{\text{τ}}_{12}^2}{{\text{S}}^2}$

Where, the failure parameters $X$ and $Y$ depends on the considered quadrant of the coordinate plane, being $\text{X}=X_T$ or $\text{X}=X_C$ if ${\text{σ}}_1\ge 0$ or ${\text{σ}}_1<0$ and the same for $Y$ .

Syntax

HillFT(tensor,xt,xc,yt,yc,s,sets,plies,elems,parts,props,pool_name,layer_index,opt_str)

Arguments

tensor

Stress table

xt

Allowable tensile stress in ply material direction 1

xc

Allowable compressive stress in ply material direction 1

yt

Allowable tensile stress in ply material direction 2

yc

Allowable compressive stress in ply material direction 2

s

Allowable in-plane shear stress

sets

Set table (D=NULL)

plies

Ply table (D=NULL)

elems

Element table (D)

parts

Part table (D)

props

Property table (D)

pool_name

Pool name (D=@current_pool)

layer_index

Layer index (D=@current_slice_index)

opt_str

This is an optional argument, which can passed if needed (D=option).