Przekwas, A. J., Garimella++, H. T., Tan, X. G., Chen, Z.J. Miao, Y., Harrand, V., Kraft, R. H., Gupta, R. K., Biomechanics of Blast TBI With Time-Resolved Consecutive Primary, Secondary, and Tertiary Loads. Military Medicine. Accepted.
Garimella++, H.T., Menghani++, R.R., Gerber++, J.I.,Sridhar++, S., Kraft, R.H., Embedded finite elements for modeling axonal injury. Annals of Biomedical Engineering. Accepted (Nov. 10, 2018).
Marinov++, T., Yuchi++, L., Adewole, D.O., Cullen, D.K., Kraft, R.H. A Computational Model of Bidirectional Axonal Growth in Micro-Tissue Engineered Neuronal Networks (micro-TENNs). bioRxiv 369843. doi: https://doi.org/10.1101/369843. Link
Garimella++, H.T., Menghani++, R.R., Gerber++, J.I.,Sridhar++, S., Kraft, R.H., Embedded finite elements for modeling axonal injury. https://doi.org/10.31224/osf.io/2dx5e. Link
Gerber++, J.I., Garimella++, H.T., Kraft, R.H., Computation of history-dependent mechanical damage of axonal fiber tracts in the brain: towards tracking sub-concussive and occupational damage to the brain. BioRxiv 346700; doi: https://doi.org/10.1101/346700. Link
Dhobale++, A. V., Adewole, D. O., Chan, A. H. W., Marinov++, T., Serruya, M. D., Kraft, R.H. (Co-senior author) & Cullen, D.K. (Co-senior author), Assessing functional connectivity across three-dimensional tissue-engineered axonal tracts using calcium fluorescence imaging. Journal of Neural Engineering. https://doi.org/10.1088/1741-2552/aac96d. Link
S. Motiwale++, V. Subramani++, A. Zhou, R.H. Kraft, A Non-Linear Multi-Axial Fatigue Damage Model for the Cervical Intervertebral Disc Annulus, Advances in Mechanical Engineering. https://doi.org/10.1177/1687814018779494. Link
Ranslow++, A., Fang++, Z., & Kraft, R. H. The multiaxial failure response of porcine trabecular skull bone estimated using microstructural simulations. ASME Journal of Biomechanical Engineering. DOI: 10.1115/1.4039895. Link
Garimella++, H. T. & Kraft, R. H. (2017). A new computational approach for modeling diffusion tractography in the brain. Journal of Neural Regeneration Research, 12(1). doi: 10.4103/1673-5374.198967. Link
Lee++, C. X., Richtsmeier, J. T., & Kraft, R. H. (2017). A computational analysis of bone formation in the cranial vault using a coupled reaction-diffusion-strain model. Journal of Mechanics in Medicine and Biology. doi: 10.1142/S0219519417500737. Link.
Serruya, M. D., Harris, J. P., Adewole, D. O., Struzyna, L. A., Burrell, J. C., Nemes, A., Petrov, D., Kraft, R. H., Chen, H. I., Wolf, J. A., & Cullen, D. K. (2017). Engineered axonal tracts as “living electrodes” for synaptic-based modulation of neural circuitry. Advanced Functional Materials. doi:10.1002/adfm.201701183. Link
Extreme environments or loading include space, vehicular accidents, explosions, impacts in sports, falls, thermal fatigue and sometimes even medical procedures. This area focuses on basic research in computational biomechanics to explore new numerical methods and investigations of injury mechanisms that may result from extreme loading conditions. We are exploring multiscale approaches that capture full body biodynamics extending to multiple length and time scales with much interest in how microstuctural aspects influence macroscopic behavior. There is an emphasis on the development and integration of coupled multiphysics including thermal, mechanical and electromagnetic effects into the solution of problems. Also of interest are numerical techniques for modeling the high strain rate deformation of soft tissue, bone fracture, fluid-structure interaction, fragmentation, shock physics and other transient dynamics. There is also an interest in optimizing parallelization and solver routines and algorithms that can help deal with the complex geometry required when modeling biological materials.
The motivation for this work is to create the ability to use meshless, particle-based approaches in the simulation of shock physics problems for soft and biological materials. Traditional finite element based techniques can sometimes fail in this problem domain due to the high amounts of deformation and failure than can occur during these high rates of loading.
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The Institute for CyberScience provides high-performance computing solutions through the Advanced CyberInfrastructure (ICS-ACI) system. ICS-ACI is Penn State’s high-performance research cloud. The ICS-ACI cyberinfrastructure, which supports Penn State research computing, is also located at the University Park Campus, within a state-of-the-art data center. This data center provides 2.4MW of redundant power and 12,000 square feet of environmentally controlled space for our hardware. Approximately 50 percent of the facility’s power and equipment resources are dedicated to supporting the ICS-ACI system infrastructure. ICS-ACI operates more than 23,000 Basic, Standard and High Memory cores to support Penn State research. The system provides dual 10- or 12-core Xeon E5-2680 processors for Basic and Standard memory configurations and quad 10-core Xeon E7-4830 processors for High Memory configurations.
In the civilian population, the estimate of people living with a SCI has grown to more than 2 million people worldwide. In both the military and civilian populations, rescue and medical transport play a critical role in long-term outcome. Unfortunately, it is estimated that up to 25% of SCI may occur after the initial insult, either during transit or early in the course of medical treatment. During evacuation the goal is to provide an environment for stable and painless transport that enables optimal neurologic recovery. Air transport, one aspect of civilian and military medical evacuations, is a harsh environment and there has been limited research concerning the effects of aircraft vibration and gravitation on long-term SCI recovery. Understanding all the effects requires multidisciplinary knowledge of the mechanisms of injury, physiology, biomechanics of the spine and the extrinsic operational environment. Furthermore, spinal cord injury and recovery are related to cellular processes which lead us to the question: Do vibrational and gravitational forces during medical transport get translated to cellular damage within the spinal cord? Cellular pathophysiology has provided considerable evidence that microstructural abnormality of white matter integrity in SCI is linked with clinical outcomes. Therefore, our objective is to develop a multiscale model of spinal cord injury that can explicitly predict white matter disruption that can then be used to discover the microstructural effects of immobilization, gravitation and vibrational forces on SCI experienced during medical transport.
The PSU CBG research extends multiple length and time scales from whole body dynamics to cellular processes. Craniosynostosis is a common and complex craniofacial condition (~4 per 10,000 live births) that imposes a substantial financial and emotional burden on patients and their families. Craniosynostosis is a condition defined by premature closure of cranial vault sutures, which is associated with abnormalities of the brain and skull. Many causal relationships between discovered mutations and premature suture closure have been proposed but an understanding of the precise mechanisms remains elusive. This research develops a computational framework of biological processes underlying cranial growth that will enable a hypothesis driven investigation of craniosynostosis phenotypes using reaction-diffusion model and the finite element method. Primary centers of ossification in cranial vault are identified using an activator-inhibitor model that represents the behavior of key molecules for bone formation. Biomechanical effects due to the interaction between growing bone and soft tissue is investigated to elucidate the mechanism of growth of cranial vault.
Digital biomarkers are defined as physiological and behavioral measures collected through connected digital tools. Since mild traumatic brain injuries or concussions are difficult to quantitatively diagnose, the primary aim is to predict extent of damage using a combination of wearable sensors and computer models.
Traumatic brain injury is a debilitating injury and a significant health problem in the
United States that is estimated to occur in 1.6 to 1.8 million people annually. Axonal injury
is a common type of traumatic brain injury primarily characterized by damage to the axons.
Enhanced knowledge of the axonal deformation during a head impact may facilitate a better
understanding of the primary injury mechanism and secondary effects that may lead to functional
deficits and long-term neurodegeneration. This information may also enable the development
of improved diagnostic tools, protective measures, and rehabilitation treatments. A consensus
on the best way to study the axonal injury during the milder forms of traumatic brain injury,
such as concussion, is still lacking. The specific objectives of this study are as follows:
(1) to apply and explore the embedded element method as a viable numerical approach for white
matter modeling in the brain; (2) to implement this approach and examine the axonal strain damage
predicted by the model compared to other existing injury criterion; and (3) to apply this approach and
conduct a quantitative analysis examining the influence of impact direction
and overall axonal orientation on the extent of injury.
Dagro, A. M., McKee, P. J., Kraft, R. H., Zhang, T. G., & Satapathy, S. S. (2013). A preliminary investigation of traumatically induced axonal injury in a three-dimensional (3-D) finite element model (FEM) of the human head during blast-loading. Army Research Laboratory Technical Report (ARL-TR-6504). Link.
Vettel, J., Dagro, A. M., Gordon, S., Kerick, S., Kraft, R. H., Luo, S., Rawal, S., Vindiola, M., & McDowell, K. (2012). Brain structure-function couplings (FY11). Army Research Laboratory Technical Report (ARL-TR-5893). Link
Clayton, J. D., & Kraft, R. H. (2011). Mesoscale modeling of dynamic failure of ceramic polycrystals. Army Research Laboratory Reprint (ARL-RP-328). http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA551733.
Gozonas, G. A., McCauley, J. W., Batyrev, I. G., Casem, D., Clayton, J. D., Dandekar, D. P., Kraft, R. H., Love, B. M., Rice, B. M., Schuster, B. E., & Weingarten, N. S. (2011). Multiscale modeling of armor ceramics: Focus on AlON. Army Research Laboratory Reprint (ARL-RP-337). Link
Kraft, R. H., & Wozniak, S. L. (2011). A review of computational spinal injury biomechanics research and recommendations for future efforts. Army Research Laboratory Technical Report (ARL-TR-5673). http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA549868.
Kraft, R. H., & Dagro, A. M. (2011). Design and implementation of a numerical technique to inform anisotropic hyperelastic finite element models using diffusion-weighted imaging. Army Research Laboratory Technical Report (ARL-TR-5796). Link
Vettel, J. M., Bassett, D., Kraft, R. H., & Grafton, S. (2010). Physics-based models of brain structure connectivity informed by diffusion-weighted imaging. Army Research Laboratory Technical Reprint (ARL-RP-0355). Aberdeen Proving Ground, MD: U.S. Army Research Laboratory. Link
Swab, J. J., Wereszczak, A. A., Tice, J., Caspe, R., Kraft, R. H., & Adams, J. (2005). Mechanical and thermal properties of advanced ceramics for gun barrel applications. Army Research Laboratory Technical Report (ARL-TR-3417). http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA430400.
Wereszczak, A. A., Swab, J. J., & Kraft, R. H. (2005). Effects of machining on the uniaxial and equibiaxial flexure strength of CAP3 AD-995 Al2O3. Army Research Laboratory Technical Report (ARL-TR-3617). http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA441313.
Kraft, R. H., Fielding++, R. A., Lister, K., Shirley, A., Marler, T., Merkle, A. C., Przekwas, A. J., Tan, X. G., & Zhou, X. (2016). Modeling skeletal injuries in military scenarios. Mechanobiology and mechanophysiology of military-related injuries Springer Berlin Heidelberg. Link.
Clayton, J. D., & Kraft, R. H. (2011). Mesoscale modeling of dynamic failure of ceramic polycrystals. In: Advances in Ceramic Armor VII: Ceramic Engineering and Science Proceedings (eds. J. J. Swab, S. Widjaja and D. Singh). Ch. 21. pp. 237-248. John Wiley & Sons. doi:10.1002/9781118095256.ch21. Link
Ranslow, A. N. (Supervised Student Author – Graduate Student), Kraft, R. H., Shannon, R. (Supervised Student Author – Undergraduate Student), De Tomas-Medina, P. (Supervised Student Author – Undergraduate Student), Radovitsky, R., Jean, A., Hautefeuille, M. P., Fagan, B., Ziegler, K. A., Weerasooriya, T., Dileonardi, A. M., Gunnarsson, A., & Satapathy, S. Microstructural analysis of porcine skull bone subjected to impact loading. Volume 3: Biomedical and Biotechnology Engineering, (pp. pp. V003T03A057; 10 pages). American Society of Mechanical Engineers Congress and Explosion. https://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=2500553. ISBN/ISSN #/Case #/DOI #: doi:10.1115/IMECE2015-51979
Lee++, C., & Kraft, R. H. (2016). A coupled reaction-diffusion-strain model for bone growth in the cranial vault. Proceedings of the 2016 Summer Biomechanics, Bioengineering and Biotransport Conference (SB3C2016). Link
Ranslow++, A. N., & Kraft, R. H. (2016). The development of a “fuzzy” yield envelope for trabecular porcine skull bone using numerical simulations. Proceedings of the 2016 Summer Biomechanics, Bioengineering and Biotransport Conference (SB3C2016). Link
Motiwale++, S., Eppler, W., Hollingsworth, D., Hollingsworth, C., Morgenthau, J., & Kraft, R. H. (2016). Application of Neural Networks for Filtering Non-Impact Transients Recorded from Biomechanical Sensors. Proceedings of the IEEE International Conference on Biomedical and Health Informatics. (pp. 204 – 207). DOI #: 10.1109/BHI.2016.7455870. Link
Reddy, S. N., Fielding++, R. A., Robinson++, M. J., & Kraft, R. H. (2015). A computational study of fracture in the calcaneus under variable impact conditions. Volume 3: Biomedical and Biotechnology Engineering, (pp. pp. V003T03A058; 10 pages). American Society of Mechanical Engineers Congress and Explosion. doi: 10.1115/IMECE2015-51984. Link
Garimella++, H. T., Yaun++, H., Johnson, B. D., Slobounov, S., & Kraft, R. H. (2015). Anisotropic constitutive model of human brain with intravoxel heterogeneity of fiber orientation using diffusion spectrum imaging (DSI). Volume 3: Biomedical and Biotechnology Engineering, (pp. pp. V003T03A011; 9 pages). Proceedings of the 2014 American Society of Mechanical Engineers Congress and Exposition. DOI #:10.1115/IMECE2014-39107. Link
Fielding++, R. A., Tan, X. G., Przekwas, A. J., Kozuch++, C. D., & Kraft, R. H. (2015). High rate impact to the human calcaneus: A micromechanical analysis. Volume 3: Biomedical and Biotechnology Engineering, (pp. V003T03A009, (8 pages)). American Society of Mechanical Engineers Congress and Explosion. doi: 10.1115/IMECE2014-38930. Link
Kraft, R. H., & Garimella++, H. T. Embedded finite elements for modeling traumatic axonal injury. Proceedings of the Summer Biomechanics, Bioengineering and Biotransport Conference (SB3C 2015). American Society of Mechanical Engineers. http://2015.sb3c.org/.
Makwana++, A. R., Krishna++, A. R., Yuan++, H., Kraft, R. H., Zhou, X., Przekwas, A. J., & Whitley, P. (2014). Towards a micromechanical model of intervertebral disc degeneration under cyclic loading. (pp. pp. V003T03A012; 7 pages). American Society of Mechanical Engineers Congress and Explosion. doi: 10.1115/IMECE2014-39174. Link
Lee++, C., Richtsmeier, J. T., & Kraft, R. H. (2014). A multiscale computational model for the growth of the cranial vault in craniosynostosis. (pp. V009T12A061; 6 pages). American Society of Mechanical Engineers Congress and Exposition (IMECE). doi: 10.1115/IMECE2014-38728. Link
Fielding++, R. A., Kraft, R. H., Ryan, T. M., & Stecko, T. D. (2014). A micromechanics-based simulation of calcaneus fracture and fragmentation due to impact loading. 11th World Congress on Computational Mechanics (WCCM XI) 5th. European Conference on Computational Mechanics (ECCM V) 6th. European Conference on Computational Fluid Dynamics (ECFD VI). Link
Zhang, J., Merkle, A. C., Carneal, C. M., Armiger, R. S., Kraft, R. H., Ward, E. E., Ott, K. A., Wickwire, A. C., Dooley, C. J., Harrigan, T. P., & Roberts, J. C. (2013). Effects of torso-borne mass and loading severity on early response of the lumbar spine under high-rate vertical loading. 2013 International Research Council on Biomechanics of Injury (IRCOBI) Conference Proceedings. 11-13 September 2013. Gothenburg, Sweden. Link.
Kraft, R. H., Dagro, A. M., McKee, P. J., Grafton, S. T., Vettel, J., McDowell, K., Vindiola, M., & Merkle, A. C. (2013). Combining the finite element method with structural network-based analysis for modeling neurotrauma. (pp. 4). 11th International Symposium, Computer Methods in Biomechanics and Biomedical Engineering. Salt Lake City, Utah. Link
Scheidler, M., Fitzpatrick, J., & Kraft, R. H. (2011). In Tom Proulx (Ed.), Optimal pulse shapes for SHPB tests on soft materials. 1, (pp. 259-268). Society for Experimental Mechanics Series, Dynamic Behavior of Materials. ISBN/ISSN #/Case #/DOI #: 2191-5644. Link
Kraft, R. H., Lynch, M. L., & Vogel, E. W. (2011). Computational failure modeling of lower extremities. RTO-MP-HFM-207AC/323(HFM-207)(TP/412). NATO Human Factors and Medicine Panel. DOI #: 10.14339/RTO-MP-HFM-207-13-pdf. Link
Clayton, J. D., & Kraft, R. H. (2011) . Mesoscale modeling of dynamic failure of ceramic polycrystals. Proceedings of the 35th International Conference on Advanced Ceramics and Composites.
Vettel, J. M., Bassett, D. S., Kraft, R. H., & Grafton, S. T. (2010). Physics-based models of brain structure connectivity informed by diffusion weighted imaging. 27th Army Science Conference. Link
Gazonas, G. A., McCauley, J. W., Kraft, R. H., Love, B. M., Clayton, J. D., Casem, D., Dandekar, D., Rice, B., Batyrev, I., Weingarten, N. S., & Schuster, B. E. (2010). Multiscale modeling of armor ceramics: Focus on AlON. 27th Army Science Conference.
Scheidler, M., & Kraft, R. H. (2010). In C. P. Hoppel (Ed.), Inertial effects in compression Hopkinson bar tests on soft materials. U.S. Army Research Laboratory, 1st Annual ARL Ballistic Technology Workshop.
Kraft, R. H., Batyrev, I., Lee, S., Rollett, A. D., & Rice, B. (2010). In J. J. Swab, S. Mathur and T. Ohji (Eds.), Multiscale modeling of armor ceramics. Journal of the American Ceramics Society Meeting Proceedings., 31 . Hoboken, NJ: John Wiley & Sons, Inc. DOI: 10.1002/9780470944004. Link
Wereszczak, A. A., & Kraft, R. H. (2003). In W. M. Kriven and H. T. Lin (Eds.), Flexural and torsional resonances of ceramic tiles via impulse excitation of vibration. 24(4), (pp. 207-213). 27th Annual Conference on Advanced Ceramics and Composites: B: Ceramic Engineering and Science Proceedings. http://onlinelibrary.wiley.com/doi/10.1002/9780470294826.ch31/summary. ISBN/ISSN #/Case #/DOI #: DOI: 10.1002/9780470294826.ch31
Wereszczak, A. A., & Kraft, R. H. (2002). In H. T. Lin and M. Singh (Eds.), Instrumented Hertzian indentation of armor ceramics. 23(3), (pp. 11). 26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings. http://onlinelibrary.wiley.com/doi/10.1002/9780470294741.ch7/summary. ISBN/ISSN #/Case #/DOI #: DOI: 10.1002/9780470294741.ch7.
Garimella++, H. T., & Kraft, R. H. (2016). Modeling the mechanics of axonal fiber tracts using the embedded finite element method. International Journal for Numerical Methods in Biomedical Engineering (e02823), 1–21. DOI #: 10.1002/cnm.2796. Link
Fielding++, R. A., Przekwas, A. J., Tan, X. G., & Kraft, R. H. (2015). Development of a lower extremity model for high strain rate impact loading. International Journal of Experimental and Computational Biomechanics, 3(2), 161-186. Link
Lee++, C. X., Richtsmeier, J. T., & Kraft, R. H. (2015). A Computational Analysis of Bone Formation in the Cranial Vault in the Mouse. Frontiers in Bioengineering and Biotechnology, 3(24). doi: 10.3389/fbioe.2015.00024. Link.
Swab, J. J., Tice, J., Wereszczak, A. A., & Kraft, R. H. (2014). Fracture toughness of advanced structural ceramics: Applying ASTM C1421. Journal of the American Ceramic Society, pp. 1-9. doi:10.1111/jace.13293. Link
Clayton, J. D., Kraft, R. H., & Leavy, R. B. (2012). Mesoscale modeling of nonlinear elasticity and fracture in ceramic polycrystals under dynamic shear and compression. Journal of Solids and Structures, 49(18), 6. doi:10.1016/j.ijsolstr.2012.05.035. Link
Kraft, R. H., Mckee, P. J., Dagro, A. M., & Grafton, S. T. (2012). Combining the finite element method with structural connectome-based analysis for modeling neurotrauma: Connectome neurotrauma mechanics. PLoS Computational Biology, 8(8), e1002619. http://dx.doi.org/10.1371%2Fjournal.pcbi.1002619. Link
Kraft, R. H., & Molinari, J. F. (2008). A statistical investigation of the effects of grain boundary properties on transgranular fracture. Acta Materialia, 56(17), 10. doi:10.1016/j.actamat.2008.05.036. Link
Kraft, R. H., Molinari, J. F., Ramesh, K. T., & Warner, D. W. (2008). Computational micromechanics of dynamic compressive loading of a brittle polycrystalline material using a distribution of grain boundary properties. The Journal of Mechanics and Physics of Solids, 56, 23. doi:10.1016/j.jmps.2008.03.009.Link