Contact Information Tel: (213) 740-3615
Dr. Amy Rechenmacher
Dr. Amy Rechenmacher
Sonny Astani Department of
Civil and Environmental Engineering
University of Southern California
3620 S. Vermont Avenue, KAP 230C
Los Angeles, CA 90089-2531
Fax: (213) 744-1426
Tel: (213) 740-3615
Iowa State University
Honors and Awards
Granular materials, such as soils, pharmaceutical powders, and grains in a silo, form an interesting class of material: when stable, they behave as solids, but upon the initiation of failure, they flow like liquids. This “phase” transition between jammed and unjammed states currently cannot be described accurately by mechanical or thermodynamic models. The primary means of force transmission in granular materials is via “force chains”. Force chain collapse further induces vortices, and in turn turbulent flow characteristics, during localized shearing in dense granular layers. As a means of advancing understanding of granular material behavior, we use digital imaging methods to experimentally track particle-scale movement in granular materials, as a means to characterize and understand force chain and vortex behavior in sheared, dense granular layers.
Fault gouge is the product of wear along slipping surfaces in an earthquake fault. Generally, more mature faults, with much accumulated slip, contain more gouge, and exhibit different earthquake slip signatures than faults with less gouge. It is hypothesized that force chains, or “grain bridges”, play an important role in the rate- and state-dependent response of fault gouge and in turn impact fault stability. Our current efforts are directed toward developing experimental methods to simulate fault gouge response in the laboratory, and to characterize the role of force chains and grain breakage on gouge evolution.
Walker, D.M., Tordesillas, A., Pucilowski, S., Lin, Q., Rechenmacher, A.L., Abedi, S. (2012), “Analysis of grain-scale measurements of sand using kinematical complex networks,” International Journal of Bifurcation and Chaos, accepted.
Rechenmacher, A.L., Abedi, S., Chupin, O., and Orlando, A.D. (2011), “Characterization of Mesoscale Instabilities in Localized Granular Shear using Digital Image Correlation,” Acta Geotechnica, in press, DOI: 10.1007/s11440-011-0147-2
Chupin, O. and Rechenmacher, A.L. and Abedi, S. (2010), “Finite Strain Analysis of Non-Uniform Deformations in Shear Bands in Sand,” International Journal of Numerical and Analytical Methods in Geomechanics, in press, DOI: 10.1002/nag.1071
Rechenmacher, A., Abedi, S. and Chupin, O. (2010) “Evolution of Force Chains in Shear Bands in Sand,” Geotechnique, 60 (5), 343-351.
Medina-Cetina, Z. and Rechenmacher, A.L. (2010), “Influence of Boundary Conditions, Specimen Geometry and Material Heterogeneity on Model Calibration from Triaxial Tests,” International Journal of Numerical and Analytical Methods in Geomechanics, 34 (6), 627-643.
Rechenmacher, A.L. and Medina-Cetina, Z. (2007), “Calibration of Soil Constitutive Models with Heterogeneous Parameters,” Journal of Geotechnical and Geoenvironmental Engineering, 133 (12) 1567-1576.
Rechenmacher, A.L. (2006), “Grain-scale processes governing shear band initiation and evolution in sands,” Journal of the Mechanics and Physics of Solids, 54, 22-45.
Rechenmacher, A.L. and R.J. Finno (2004), "Digital Image Correlation to Evaluate Shear Banding in Dilative Sands," Geotechnical Testing Journal, 27 (1), 13-22.
Finno, R.J. and A.L. Rechenmacher (2003), "Effects of Consolidation History on Critical State of Sand," Journal of Geotechnical and Geoenvironmental Engineering, 129 (4), 350-360.