γm
|
Fracture surface work for forming a crack in the matrix |
εcs
|
Composite strain at crack stabilization stage |
εcu
|
Composite strain at failure |
εmu
|
Failure strain of the matrix |
εfu
|
Failure strain of the fiber |
σc
1
|
Composite stress corresponding to the formation of the first crack |
σcdrop
|
Drop in composite stress after the formation of the first crack |
σcu
|
Composite tensile failure stress |
σmu
|
Tensile strength of the matrix |
σfu
|
Tensile strength of the fiber |
τs
|
Frictional bond strength |
a
|
Factor for calculating the composite strain at the crack stabilization stage |
df
|
Fiber diameter |
Ec
1
|
Initial elastic modulus of the composite |
Ec
2
|
Elastic modulus of the composite after the formation of the first crack |
Ecxo
|
Elastic modulus of the composite along the debonded interface |
Em
|
Elastic modulus of the matrix |
Ef
|
Elastic modulus of the fiber |
fm,c
|
Compressive strength of the matrix |
fm,fl
|
Flexural strength of the matrix |
Gm
|
Matrix fracture energy |
ki
|
Equivalent stiffness of a composite zone with full fiber–matrix bond |
kxo
|
Equivalent stiffness of the composite along the debonding length |
ltot
|
Total length of specimen |
li
|
Lengths of specimen sections with full matrix–fiber bond |
xo
|
Debonding length |
Vf
|
Fiber volume |
Vf,crit
|
Critical fiber volume |
Vm
|
Matrix volume |