multiPlas - Dynardo GmbH

1 INTRODUCTION
This manual describes the use of Dynardo’s software product multiPlas for ANSYS. multiPlas is a library
of elasto-plastic material models for ANSYS.
The elasto-plastic material models in multiPlas, enable the user to simulate elasto-plastic effects of artificial
materials, e.g. steel or concrete, and natural born materials, e.g. soil or rock, in geotechnics, civil
engineering - as well as - mechanical engineering.
In the context of finite element calculations with ANSYS, multiPlas provides an efficient and robust algorithm
for the handling of single and multi-surface plasticity. The material models are based on elastoplastic
flow functions with associated and non-associated flow rules. One special feature of the multiPlas
material models is the combination of isotropic and anisotropic yield conditions.
The multiPlas material models are available for structural volume elements (e.g. SOLID 45, SOLID 95),
for structural shell elements (e.g. SHELL 43, SHELL 93) and structural plane elements (e.g. PLANE 42,
PLANE 82).
The following material models and features are provided:
Model Application Flow Rule
isotropic Material Models:
Stress-Strain
Response
Tresca Steel, ... associative
bilinear,
ideal elastic-plastic
Mohr-Coulomb
Soil, Rock, Stone,
Masonry, ... non-associative
von Mises Steel, ... associative
Drucker-Prager Soil, Stone, ... associative
modified
Drucker-Prager
Stone, Cement,
Concrete, ... associative
Temperature
Dependency
bilinear,
residual strength yes
bilinear,
ideal elastic-plastic
bilinear,
ideal elastic-plastic
bilinear,
ideal elastic-plastic yes
Concrete, Cement,
nonlinear hardening
Concrete Stone, Brick, ... non-associative and softening yes
Tension cut off rotated cracking associative residual strength
anisotropic Material Models:
Joints, jointed
Rock, Cohesive
bilinear,
Mohr-Coulomb Zones, ... non-associative residual strength
Masonry_Ganz Masonry, ... non-associative
Tsai / Wu Wood, ... associative
boxed value Wood, ... associative
Tension cut off
fixed cracking,
Cohesive Zones associative
nonlinear hardening
and softening yes
bilinear,
ideal elastic-plastic
multilinear hardening
and softening
residual strength /
exponential softening
Additionally, all Mohr-Coulomb Models are coupled with a tension cut-off yield surface.
In simulations of joint materials (e.g. jointed rock), it is possible to arrange the joint sets arbitrarily.
Isotropic and anisotropic Mohr-Coulomb yield surfaces can be combined in manifold ways. Up to 4 joint
sets can be associated with an isotropic strength definition.
MultiPlas has been successfully applied in nonlinear simulations of and concrete as well as in stability
analysis of soil or jointed rock.
5
USER’S MANUAL, January, 2013