LS-DYNA and DYNA3D Experience
Dr. Schwer has been a DYNA3D user since 1982, and an LS-DYNA user since 1998.
While employed at SRI International, Dr. Schwer became one of the first DYNA3D users,
outside of Lawrence Livermore National Laboratory (LLNL), and helped to motivate Dr. John
Hallquist to convert the Cray computer based version of DYNA3D to the then new DEC VAX/VMS
computer. Dr. Schwer also provided Dr. Hallquist with one of his first, if not the first,
consulting opportunities through SRI to implement into DYNA3D and DYNA2D a Mohr-Coulomb
material developed by Dr. Schwer for the NONSAP code. Drs. Schwer and Hallquist have
maintained both a collegial and personal relationship through out the years, to include:
- Co-authoring a publication on viscoelastic modeling of an energy absorbing bumper
- Schwer, L.E., W. Cheva, and J.O. Hallquist, ``A Simple Viscoelastic Model for Energy
Absorbers Used in Vehicle-Barrier Impact,'' in Computational Aspects of Contact, Impact,
and Penetration, Edited by R.F. Kulak and L.E. Schwer, Elmepress International, Lausanne,
Switzerland, pp. 99-117, 1991.
- Working as a consultant to LSTC, in 1991 and 1997, in writing parts of the LS-DYNA
Theoretical Manual; Dr. Schwer is mentioned in the Acknowledgements section of the manual.
In addition to his relationship with Dr. Hallquist, Dr. Schwer has worked in the past
with other LSTC employees:
- Mr. Jim Day worked with Dr. Schwer while they were employed at Lockheed Missile and
Space Corporation in Sunnyvale CA and they have co-authored two peer reviewed publication
on using DYNA2D and DYNA3D to model earth penetration:
- Schwer, L.E., R. Rosinsky, and J. Day, ``Axisymmetric Lagrangian Technique for
Predicting Earth Penetration Including Penetrator Response,'' International Journal for
Numerical and Analytical Methods in Geomechanics, Vol. 12, No. 3, pp. 235-262, May-June
- Schwer, L.E. and J. Day, ``Computational Techniques for Penetration of Concrete and
Steel Targets by Oblique Impact of Deformable Projectiles,'' Nuclear Engineering and
Design, Vol. 125, pp. 215-238, 1991.
- Dr. Chen Tsay worked with Dr. Schwer while Dr. Tsay was employed as the Vice President
and lead code developer at KBS2 Inc. and Dr. Schwer was a consultant to KBS2.
In parallel with Dr. Schwers experience in working with LSTC staff, he has also
worked very closely with Drs. Bruce Engelmann and Robert Whirley who took over the LLNL
development of NIKE and DYNA, respectively, after Dr. Hallquist left LLNL to form LSTC.
Dr. Schwer has also worked with the current LLNL DYNA3D developer Dr. Jerry Lin while Dr.
Lin was employed at KBS2 and Dr. Schwer served as a consultant. Of these three individual,
the work with Dr. Whirley has been the most extensive and continues today with Dr. Schwer
working as a consultant to TransMotive Technologies Inc where Dr. Whirley is the Vice
President. Drs. Schwer and Whirley have co-authored two peer reviewed publication
involving the development and application of DYNA3D features:
- Schwer, L.E. and R.G. Whirley, ``Lessons Learned in Modeling a Moving Deformable Barrier
(MDB) Impacting a Rigid Wall,'' International Journal of Crashworthiness, Vol. 1, No. 1,
- Schwer, L.E. and R.G. Whirley, "Impact of a 3D Woven Textile Composite Panel:
Damage and Failure," accepted for publication Mechanics of Composite Materials and
Structures, July 1998.
Dr. Schwers extensive experience in applying DYNA3D to numerous problems and
developing new capabilities for DYNA3D is in part documented by his DYNA3D related
publications. In addition to the book chapter and four peer reviewed publication mentioned
above, the following six peer reviewed publications are DYNA3D related:
- Lindberg, H.E., M.B. Rubin, and L.E. Schwer, ``Dynamic Buckling of Cylindrical Shells
from Oscillating Waves Following Axial Impact,'' International Journal of Solids and
Structures, Vol. 23, No. 6, pp. 669-692, 1987.
- Schwer, L.E., B.S. Holmes, and S.W. Kirkpatrick, ``Response and Failure of Metal tanks
from Impulsive Spot Loading: Experiments and Calculations,'' International Journal of
Solids and Structures, Vol. 24, No. 8, pp. 817-833, 1988.
- Schwer, L.E. and H.E. Lindberg, ``A Finite Element Slideline Approach for Calculating
Tunnel Response in Jointed Rock,'' International Journal for Numerical and Analytical
Methods in Geomechanics, Vol. 16, pp. 529-540, 1992.
- Murray, Y.D. and L.E. Schwer, ``Verification of a General Purpose Laminated Composite
Shell Element Implementation: Comparisons with Analytical and Experimental Results,''
Finite Elements in Analysis and Design, Vol. 12, pp. 1-16, 1993.
- Schwer, L.E., ``A Viscoplastic Augmentation of the Smooth Cap Model,'' Nuclear
Engineering and Design, Vol. 150, pp. 215-223, 1994.
- Schwer, L.E. and Y.D. Murray, ``A Three-Invariant Smooth Cap Model with Mixed
Hardening,'' International Journal for Numerical and Analytical Methods in Geomechanics,
Volume 18, pp. 657-688, 1994.
Experience in using and developing DYNA3D for a wide variety of engineering mechanics
problem areas has led to Dr. Schwer serving as a consultant. In addition to LSTC, KBS2,
and TransMotive, mentioned above, Dr. Schwer has served as a consultant to Exponent, Inc
(formerly Failure Analysis Associates), APTEK, Inc., Rocket Research (a Division now of
Rockwell), Weidlinger Associates, Kaman Sciences, Columbine Bus, and Titan Corporation.