The input data for the maximum strain failure theory are tensile and compressive
strain limits, and in the local X-direction; and in the local Y-direction; and in the local Z-direction; and shear strain limits (maximum shear
strains), , and in the local X–Y, X–Z, and Y–Z planes, respectively. All strain
limits must be positive.
If , ; otherwise, . If , ; otherwise, If , ; otherwise, .
The maximum strain-based damage initiation criterion is met when the following
condition is satisfied for a three-dimensional strain state, :
Input File Usage
Use the following option to define the maximum strain-based damage initiation
criterion:
The input data for the maximum stress failure theory are tensile and compressive
stress limits, and in the local X-direction; and in the local Y-direction; and in the local Z-direction; and shear strengths (maximum shear
stresses), , and in the local X–Y, X–Z, and Y–Z planes, respectively. All stress
limits must be positive.
If , ; otherwise, . If , ; otherwise, If , ; otherwise,
The maximum stress-based damage initiation criterion is met when the following
condition is satisfied for a three-dimensional stress state, :
Input File Usage
Use the following option to define the maximum stress-based damage initiation
criterion:
The strain-based Tsai-Wu damage initiation criterion is based on the theory of Tsai (1971).The strain-based Tsai-Wu damage initiation criterion is met when
the following condition is satisfied for a three-dimensional strain state :
where are material properties related to material maximum strain
limits.
Input File Usage
Use the following option to define the Tsai-Wu strain-based damage initiation
criterion:
The stress-based Tsai-Wu damage initiation criterion is based on the theory of Tsai (1971).The stress-based Tsai-Wu damage initiation criterion is met when
the following condition is satisfied for a three-dimensional stress state :
where are material properties related to material stress strengths.
Input File Usage
Use the following option to define the Tsai-Wu stress-based damage initiation
criterion:
In Abaqus/Explicit, each damage initiation criterion can depend either on the equivalent strain
rate, , or on the strain rate components, , with the equivalent strain rate defined as
and the strain rate components defined as
In the above definitions <> represents the Macaulay bracket operator, and represents the absolute value of . These definitions ensure that strain rate dependency is taken
into consideration during monotonic loading only (increasing equivalent strain or
absolute value of strain components).
Input File Usage
Use the following option to define strain rate-dependent damage initiation
criterion:
Each damage initiation criterion defines a failure surface surrounding the origin.
Failure occurs whenever a state of stress or strain is either on or outside this
surface. The failure index, , is used to measure the proximity to the failure surface. is defined as the (dimensionless) scaling factor such that, for a
given stress state or a given strain state ,
that is, is the scaling factor by which we need to multiply all the stress
or strain components simultaneously to lie on the failure surface. Values indicate that the state of stress is within the failure surface,
while values indicate failure.
Elements
The general stress- and strain-based damage initiation criteria can be used with any
elements in Abaqus that include mechanical behavior (elements that have displacement degrees of
freedom).