Jorgen Bergstrom, Ph.D.

Professional Profile

Dr. Jorgen Bergstrom is working at Veryst Engineering, a consulting firm located in Boston, Massachusetts. Dr. Bergstrom consults primarily in the modeling, testing, and analysis of mechanical behavior of materials, particularly polymeric materials and MEMS. His consulting work includes sensor design and analysis, polymer windows, gaskets and hoses, injection molded components, and polymer films. He has worked with the National Institute of Health and Department of Defense on the modeling of material behavior. He has developed world-recognized models for simulating the large deformation, rate-dependent, non-linear behavior of thermoplastics and thermosets. In addition to theoretical modeling Dr. Bergstrom has significant experience with experimental material characterization, including mechanical testing, calorimetry, microscopy, and spectroscopy.

Dr. Bergstrom also works with particle and fiber-filled polymer composites. He has additional expertise in the behavior of brittle materials such as ceramics, ice, and rocks. This expertise includes research in crack nucleation, crack coalescence, and shear fault formation in brittle solids. Dr. Bergstrom also specializes in different computer simulation techniques, including finite element modeling, molecular dynamics, and Monto Carlo simulations. Dr. Bergstrom's expertise is applicable to problems in material processing, manufacturing simulation, product design, and failure analysis.

Dr. Bergstrom is a Lecturer in the Department of Mechanical Engineering at MIT.

Dr. Bergstrom is the creator and maintainer of PolymerFEM.com, a web site focusing on teaching and disussing constitutive models for polymers and their implementation in general purpose finite element programs.

Dr. Bergstrom is also the creator and maintainer of PolyUMod.com a website dedicated to the PolyUMod library of user material models, and the MCalibration software for material model calibration.

Credentials and Professional Honors

Ph.D., Mechanical Engineering, Massachusetts Institute of Technology, 1999
M.S., Mechanical Engineering, Thayer School of Engineering, Dartmouth College, 1995
B.S., Mechanical Engineering, Thayer School of Engineering, Dartmouth College, 1993
B.S., Mechanical Engineering, Royal Institute of Technology, Stockholm, Sweden, 1992

Sigma Xi, Scientific Research Honor Society; The Charles F. and Ruth D. Goodrich Prize, Dartmouth College, 1995; George Austin Colligan Fellow, Dartmouth College, 1993; The General Scholarship, Royal Institute of Technology, 1990, 1992; The Scholarship of Sandviken, Royal Institute of Technology, 1992

American Society of Mechanical Engineers
The Society of Plastics Engineers
Certified Composites Technician

Books and Book Chapters

"Modeling and Mechanical Analysis of Fluoropolymer Components," in Fluoropolymers Applications: Chemical Processing Industry - The Definitive User's Guide and Databook. Edited by Sina Ebnesajjad, Plastics Design Library, Williams Andrew Publishing, 2004.

"Computer Modeling and Simulation of UHMWPE," in Ultra-High Molecular Weight Polyethylene Handbook. Edited by Steven Kurtz, Elsevier, 2004.

Publications

"An Augmented Hybrid Constitutive Model for Simulation of Unloading and Cyclic Loading Behavior of Conventional and Highly Crosslinked UHMWPE," Biomaterials, Vol. 25, pp. 2171-2178, 2004 (with C.M. Rimnac and S.M. Kurtz).

"A Constitutive Model for Predicting the Large Deformation Thermomechanical Behavior of Fluoropolymers," submitted to Mechanics and Materials, 2003 (with L.B. Hilbert).

"Molecular Chain Stretch is a Multiaxial Failure Criterion for Conventional and Highly Crosslinked UHMWPE," submitted to Journal of Orthopaedic Research, 2003 (with C.M. Rimnac and S.M. Kurtz).

"Prediction of Multiaxial Mechanical Behavior for Conventional and Highly Crosslinked UHMWPE Using a Hybrid Constitutive Model," Biomaterials, Vol 24, pp. 1365-1380, 2003 (with S.M. Kurtz and C.M. Rimnac).

"Thermomechanical Behavior of Virgin and Highly Crosslinked Ultra-High Molecular Weight Polyethylene Used in Total Joint Replacements," Biomaterials, Vol. 23, pp. 3681-3697, 2002 (with S.M. Kurtz, M.L. Villarraga, M.P. Herr, C.M. Rimnac, and A.A. Edidin).

"Constitutive Modeling of Ultra-High Molecular Weight Polyethylene under Large-Deformation and Cyclic Loading Conditions," Biomaterials, Vol. 23, pp. 2329-2343, 2002 (with S.M. Kurtz, C.M. Rimnac, and A.A. Edidin).

"Miniature Specimen Shear Punch Test for UHMWPE used in Total Joint Replacements," Biomaterials, Vol 23, pp. 1907-1919, 2002 (with S.M. Kurtz, C.W. Jewett, J.R. Foulds and A.A. Edidin).

"A Progressive Damage Model for Failure by Shear Faulting in Polycrystalline Ice under Biaxial Compression," Int. J. Plasticity, Vol 18, pp. 507-530, 2002 (with. V. Gupta).

"Constitutive Modeling of the time-dependent and cyclic loading of elastomers and application to soft biological tissues," Mechanics of Materials, Vol. 33, pp. 523-530, 2001 (with. M.C. Boyce).

"Deformation of Elastomeric Networks: Relation between Molecular Level Deformation and Classical Statistical Mechanics Models of Rubber Elasticity," Macromolecules, Vol. 34, No. 3, pp. 614-626, 2001 (with M.C. Boyce).

"Large Strain Time-Dependent Behavior of Filled Elastomers," Mechanics of Materials, Vol. 32, pp. 627-644, 2000 (with M.C. Boyce).

"Mechanical Behavior of Particle Filled Elastomers," Rubber Chem. Tech., Vol. 72, pp. 633-656, 1999 (with M.C. Boyce).

"Large Strain Time-Dependent Behavior of Elastomeric Materials," Ph.D. Thesis, MIT, 1999.

"Constitutive Modeling of the Large Strain Time-Dependent Behavior of Elastomers," J. Mech. Phys. Solids, Vol. 46, pp. 931-954, 1998 (with M.C. Boyce).

"Compressive Failure of Rocks by Shear Faulting," J. Geophys. Research-B: Solid Earth, Vol. 103, No. B10, pp. 23875-23895, 1998 (with V. Gupta).

"Effect of Step-Loading History and Related Grain-Boundary Fatigue in Freshwater Columnar Ice in the Brittle Deformation Regime," Phil. Mag. Letters, Vol. 77, No. 5, pp. 241-247, 1998, (with V. Gupta and C.R. Picu).

"Nucleation of Splitting Cracks in Columnar Freshwater Ice," Acta Mater, Vol. 45, No. 4, pp. 1411-1423, 1997 (with V. Gupta, and C.R. Picu).

"Brittle Failure of Columnar Freshwater Ice under Off-Axis Compression Loading," Scripta Materialia, Vol. 36, No. 1, pp. 63-67, 1997 (with C.R. Picu, and V. Gupta).

Presentations and Published Abstracts

"Distributions of Ultimate Properties for Conventional and Highly Crosslinked UHMWPE," paper presented at the 7th World Biomaterials Congress, Sydney, Australia, May 2004 (with S.M. Kurtz and C.M. Rimnac).

"Failure Predictions of Highly Crosslinked UHMWPE," paper presented at the 7th World Biomaterials Congress, Sydney, Australia, May 2004 (with S.M. Kurtz and C.M. Rimnac).

"Predicting Failure Risk of TKA Designs Incorporating Highly Crosslinked UHMWPE," paper presented at the 7th World Biomaterials Congress, Sydney, Australia, May 2004 (with S.M. Kurtz, T. Harrigan, and C.M. Rimnac).

"Ultimate Property Distributions for Conventional and Highly Crosslinked UHMWPE," paper presented at the 50th Annual Meeting of the Orthopaedic Research Society, San Fransisco, CA, March 2004 (with S.M. Kurtz, and C.M. Rimnac).

"Analysis of Stresses and Fracture Risk for Posterior-Stabilized TKA Designs Incorporating Highly Crosslinked UHMWPE," paper presented at the 50th Annual Meeting of the Orthopaedic Research Society, San Fransisco, CA, March 2004 (with S.M. Kurtz, T. Harrigan, and C.M. Rimnac).

"Evaluating Pressure Integrity of Polymer Ring Seals for Threaded Connections in HP/HT Wells and Expandable Casing," paper presented at the IADC/SPE Drilling Conference, Dallas, TX, March 2004 (with L.B. Hilbert).

"Large Strain Time- and Temperature-dependent modeling of PTFE," paper presented at 2nd MIT conference on Computational Fluid and Solid Mechanics, Cambridge, MA, June 2003 (with L.B. Hilbert, and S.B. Brown).

"Multiaxial Failure Modeling For Conventional and Highly Crosslinked UHMWPE," paper presented at 29th Annual Meeting of the Society For Biomaterials, Reno, NV, May 2003 (with S.M. Kurtz, and C.M. Rimnac).

"Finite Element Modeling for Design and Failure Analysis of Polymer Materials," MTI Materials Technology Institute of the Chemicals Process Industries, Inc., TAC Meeting, Clearwater Beach, FL, Feb 2003 (with S. Brown).

"Plastics: Issues of Litigation Exposure," Concord, NH, May 2, 2002; Manchester, NH, May 8, 2002; Pittsburgh, PA, Sept. 10, 2002; Philadelphia, PA, Sept. 16, 2002 (with C.E. Scott).

"Constitutive Modeling of Crosslinked UHMWPE for Joint Replacements," paper presented at the 48th Annual Meeting of the Orthopaedic Research Society, Dallas, TX, Feb 2002 (with S.M. Kurtz, C.M.Rimnac, and A.A. Edidin).

"Constitutive Modeling of the Large Strain Time-Dependent Behavior of Particle Filled Elastomers," 159th Spring Technical Meeting of the Rubber Division of the American Chemical Society, Providence, RI, Apr 2001.

"Constitutive Theories for UHMWPE for Monotonic and Cyclic Loading Conditions," paper presented at 27th Annual Meeting of the Society For Biomaterials, Saint Paul, MN, Apr 2001 (with S.M. Kurtz, C.M. Rimnac, and A.A. Edidin).

"Multiaxial Validation of Constitutive Theories for UHMWPE," paper presented at 27th Annual of the Society of Biomaterials, Saint Paul, MN, Apr 2001 (with S.M. Kurtz, C.M. Rimnac, and A.A. Edidin).

"Time-Dependent Deformation in Elastomeric Materials," paper presented at 35th Annual Technical Meeting of the Society of Engineering Science Inc., WA, Sep 1998 (with M.C. Boyce).

"Time-Dependence of Elastomeric Materials: Experiments and Modeling," paper presented at 10 th International Conference on Deformation, Yield and Fracture of Polymers, Cambridge, UK, Apr 1997 (with M.C. Boyce).

"Compressive Failure of Rocks," paper presented at 36 th U.S. Rock Mechanics Symposium, New York, Jun 1997 (with V. Gupta).

"Time and Strain Dependence of the Mechanical Behavior of Elastomers," paper presented at Multiscale Materials Prediction Conference, MIT, Sep 1997 (with M.C. Boyce).