Hoffman Criterion

The resulting failure index in Hoffman’s theory for an orthotropic lamina in a general state of plane stress (2D) with unequal tensile and compressive strengths is given by:

$F_{index}=\left(\frac{1}{X_T}-\frac{1}{X_C}\right){\text{σ}}_1+\left(\frac{1}{Y_T}-\frac{1}{Y_C}\right){\text{σ}}_2+\frac{{\text{σ}}_1^2}{X_T{X}_C}+\frac{{\text{σ}}_2^2}{Y_T{Y}_C}-\frac{{\text{σ}}_1{\text{σ}}_2}{X_T{X}_C}+\frac{{\text{τ}}_{12}^2}{S^2}$

Syntax

HoffmanFT(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).