Measurement of maize stalk shear moduli

Area of Science:

• Agricultural Engineering
• Materials Science
• Plant Biomechanics

Background:

• Maize is a primary feed crop in the US, with 5% annual loss due to stalk failure from wind and other factors.
• Understanding maize stalk mechanical properties is crucial for developing predictive failure models.
• The longitudinal shear modulus of maize stalk tissues has not been previously reported.

Purpose of the Study:

• To determine the longitudinal shear modulus of maize stalk tissues.
• To provide essential material constants for computational models of maize stalk failure.
• To contribute to methods for preventing crop loss in maize and similar plants.

Main Methods:

• Conducted repeated torsion testing on dry, mature maize stalks.
• Focused measurements on the hard outer rind and soft inner pith tissues.
• Performed uncertainty analysis and compared multiple methodologies to ensure data reliability.

Main Results:

• Successfully measured the longitudinal shear modulus for both maize rind and pith tissues.
• Confirmed low error and bias across all measurements through rigorous analysis.
• Established a baseline for maize stalk tissue mechanical properties under shear stress.

Conclusions:

• The reported shear modulus values are vital for accurate computational modeling of maize stalk failure.
• Improved models will aid in understanding failure mechanisms and reducing annual crop losses.
• The methodology can be adapted for characterizing tissues in other important crop plants.