Tsai-Wu Criterion

Considering the above expression for the Failure Index if we set:

$\text{A}=\frac{{\text{σ}}_1^2}{X_{\text{T}}{\text{X}}_{\text{C}}}+\frac{{\text{σ}}_2^2}{Y_{\text{T}}{\text{Y}}_{\text{C}}}+\frac{{\text{τ}}_{12}^2}{S^2}+2F_{12}{\sigma }_1{\sigma }_2$

$B=\left(\frac{1}{X_T}-\frac{1}{X_C}\right){\sigma }_1+\left(\frac{1}{Y_T}-\frac{1}{Y_C}\right){\sigma }_2$

$C = -1$

Being $$k$$ a given factor of safety, then the reserve factor formula can be evaluated as below:

${\text{RF}}_{Tsai-Wu}=\frac{-B\pm \sqrt{B^2-4AC}}{2ak}$

Syntax

TsaiWuRF(tensor,xt,xc,yt,yc,s,f12,FoS,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

f12

F12 experimental factor

FoS

Factor of Safety (D=1.0)

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).