May 21, 2025 | Iowa State University (ISU), Ames, Iowa, USA

ISTVS/ISU Symposium Chair: Professor Mehari Z. Tekeste, Director of Soil Machine Dynamic Laboratory (SMDL), Associate Professor of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, USA.

ISTVS/ISU Symposium Co-Chair: Dr. Thomas R. Way, Agricultural Engineer, USDA-ARS National Soil Dynamics Laboratory, Auburn, AL, USA.

Student organizer: Mohammed Abdeldayem, PhD, Department of Mechanical Engineering, Iowa State University, Ames, IA, USA

Digital Operations: Dr. Varsha Swamy, Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, USA

S U M M A R Y

The ISTVS/ISU Symposium on Terramechanics in Agricultural Soil-Vehicle Systems was held on May 21, 2025, at Iowa State University (ISU) in Ames, Iowa. Organized by the International Society for Terrain-Vehicle Systems (ISTVS) in collaboration with ISU, the symposium aimed to enhance awareness of ISTVS as an international society in the field of vehicle-terrain systems. The event targeted undergraduate and graduate students interested in off-road vehicle systems, engineers in the agriculture and construction equipment industries, tire and track manufacturers, digital technology developers, and farmers.

Download event schedule

S E S S I O N O V E R V I E W

There was a total of 3 sessions

(a) Welcome, opening remarks, and invited speaker talk

Welcoming speech by Professor Mehari Tekeste

Opening remarks by ISTVS President, Dr. Lutz Richter.

Invited presentation talk on The Bevameter Technique – Its present and Future by Dr. Jo Y. Wong

The symposium began with a welcome by Prof. Mehari Tekeste, followed by opening remarks from ISTVS President Dr. Lutz Richter, who emphasized the Society's mission in advancing terramechanics.

The invited speaker, Dr. Jo Y. Wong, presented on the cone penetrometer and Bevameter techniques for assessing terrain properties critical to off-road vehicle performance. He highlighted the importance of accurate soil characterization in optimizing mobility and engineering outcomes. Dr. Wong called for updated recommended practices for the Bevameter technique to improve reliability. The session reinforced how soil-tool interaction metrics guide both research and vehicle design in diverse geotechnical contexts.

To watch the presentation, please play the video below, or visit https://youtu.be/B5hNJ46UEog

(b) Technical presentations

Wear Testing and Modeling of Tools Interacting with Icy Granular Soil by Zamir Syed, Singularity Solutions, Goleta, CA

Altair’s Multiphysics Approach of Terrain-Vehicle Simulation by Eric Veikle, ALTAIR Inc., Troy, MI

Improving Soil Compaction Assessment Through Cultivator Shank Vibration Data: A Comparison with Penetrometer Readings by Shaghayegh Janbazi Alamdari, Kansas State University, Manhattan, KS

History and Vision of Soil Dynamics at Auburn University by Brock Birdsong, Acting Director, Applied Research Center, Auburn University Research and Innovation Campus, Huntsville, AL

We had three virtual presenters and five in-person presenters. The session showcased a rich blend of historical insights, novel research, and engineering innovations in soil dynamics and vehicle-terrain interaction. Bob Schafer shared the evolution of soil dynamics research at Iowa State University starting from the 50s. Brock Birdsong presented the history of the USDA-ARS-National Soil Dynamics Laboratory (NSDL) and Auburn University's initiative to revitalize and advance the NSDL soil dynamic research. Presentations ranged from modeling tool wear on icy soils (Syed) and simulating bulldozer-soil interaction (Abdeldayem), to using cultivator shank vibrations for soil compaction assessment (Janbazi Alamdari). Kraayenbrink introduced CTIS technology to reduce soil compaction in agriculture. Veikle concluded with Altair’s multiphysics simulation approach for terrain-vehicle systems.

(c) Technical discussion about terramechanics standards

In-person and virtual participants of the ISTV-ISU symposium held small-group discussions to review standard definitions for the bevameter and the ASABE soil cone penetrometer, best practices for reporting bevameter and penetrometer data for terramechanics, Bekker-Wong models, and computational modeling techniques to support vehicle mobility design and performance analysis. To help with the discussion, Prof. Wong presentation at the ISTVS-ISU symposium. Some of the technical topics from the engaged discussions and comments included: (1) geometry and design of pressure–sinkage and shear apparatus for bevameters and cone penetrometers; (2) measurement repeatability, precision, and accuracy; (3) bevameter and soil cone penetrometer data-acquisition protocols and operating parameters (annular & longitudinal shear speed, normal load, penetrometer insertion speed) and data analysis methods for estimating terramechanics soil parameters; (4) recommended practices and methods for incorporating terramechanics parameters into empirical, semiempirical, and computational vehicle-performance models; and (5) essential soil characterization (particle-size distribution, terrain type, surface cover, moisture content, bulk density, apparent cohesion, and internal friction angle). Following these discussions, ISTVS formed the Terrain Measurement and Mobility Metrics Working Group to perform a literature review and survey of measurement methods (bevameter, cone penetrometer, compaction testing) and to develop ISTVS standards for terramechanics measurement and vehicle-systems modeling.

T E C H N I C A L T O U R

Tour to Soil Machine Dynamics Laboratory (SMDL) at ISU during demonstration of mobility soil bin, scaled-blade soil bin and wear circular soil bin

P L A N N I N G & O R G A N I Z I N G C O M M I T T E E

Chair: Dr. Mehari Z. Tekeste,
Co-Chair: Dr. Thomas R. Way
Digital Operation: Dr. Varsha S Swamy
ISU-SMDL graduate students:
Mohamed A. A. Abdeldayem
John Sheriff
Satya Kosaraju
Nana Amma M Kusi Fordjour
Shadrack Gyamfi Boadi