*CONSTRAINED_BEAM_IN_SOLID keyword fixed problems in the legacy *CONSTRAINED_LAGRANGE_IN_SOLID CTYPE 2. By separating this functionality from ALE FSI, we achieved both a clean keyword card and a clean code base for future development.

Composite Modeling: Fiber reinforced plastic

By combining *CBIS with adpative EFG, Shinya Hayashi from JSOL modeled the molding process matching well against experiments. Please see the 2017 European Conference paper here and the 2018 LS-DYNA Conference paper here.

An 3-point bending example, courtesy of Shinya Hayashi from JSOL here.

Rebar concrete under cyclic loading

Using the user-defined debonding law, Ioannis Koutromanos from Virginia Tech modeled rebar concrete under cyclic loading here. Youtube Channel

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Notable features

1. Normal directional constraint only

With the CDIR = 1 option coupling occurs only in the normal directions. This coupling allows for releasing the constraints along beam axial direction.

2. Axial coupling forc.

De-bonding process can be modeled with a user defined function giving the axial shear force based on the slip between rebar nodes and concrete solid elements. This feature is invoked by setting AXFOR flag to a negative integer which refers to the *DEFINE_FUNCTION ID. CDIR has to be set to 1 in this case to release the axial constraints.

3. Additional coupling points between beam nodes

Coupling not only at nodes, but also at multiple coupling points in between the two beam element nodes. Please note, the previous implementation done in *CONSTRAINED_LAGRANGE_IN_SOLID CTYPE 2 causes errors in energy balance.

4. Non-hex elements supported

Tetrahedral and pentahedra solid elements are supported. By contrast they are treated as degenerated hexahedra in CLIS CTYPE2 implementation.

5. Essentail boundary condition supported

Velocity/Fixed boundary condition. The CTYPE 2 implementation failed to constrain beam nodes that were buried inside elements whose nodes had velocity/fixed boundary conditions prescribed.

6. Optimized searching and sorting

Sorting subroutine is optimized for larger problems to achieve better performance and less memory usage.

7. Penalty based coupling option

Penalty based coupling is available starting from dev version 119770 (not in R9 or R10). Use keyword *CONSTRAINED_BEAM_IN_SOLID_PENALTY. It is to deal with problems with large momentum transfer such as impact loading or blast loading. Using penalty formulation achieves kinetic energy conservation, which is sacrificed in constraint-based coupling.

Download executables:

1. R9.0 release: (user account)

http://ftp.lstc.com/user/mpp-dyna/R9.0.1/ for mpp

http://ftp.lstc.com/user/ls-dyna/R9.0.1/ for smp

2. Dev versions: (beta account)

http://ftp.lstc.com/beta/mpp-lsdyna/Dev/ for mpp

http://ftp.lstc.com/beta/ls-dyna/Dev/ for smp

Windows:

http://ftp.lstc.com/beta/mpp-lsdyna/Dev/windows/ for mpp

http://ftp.lstc.com/beta/ls-dyna/Dev/windows/ for smp

Please contact support@lstc.com or hao@lstc.com if you don't know username/password to download.

Note:

1. dev versions after dev.113660 might crash when used with adaptive FEM/EFG. The error message id is OTH+341.

2. dev versions between 116961 and 117300 for exes build with cmake might crash. Reason: FPE

3. dev versions between 115823 and 119431 contain a bug yeilds wrong results with CDIR=1 option.

4. Do not use dev versions between 119770 and 120795. A major algorithm change caused several bugs.