Catastrophic failure from parallel to grain tension, not shear

Mode of Failure Model for Cutting Solid Section Biomass


Solid section biomass, such as wood and the node-zone of crop residues, has distinct modes of failure when loaded in cross grain shear. Shear bar design plays a part in determining what the failure mode will be at a given depth of penetration. Other factors include shear location relative to an unconstrained end and species type. In order to design a low energy consuming shear bar for agricultural and industrial machinery such as balers and choppers, one needs to develop a predictive model of the failure modes to minimize energy consumption. Utilizing a purpose built instrumented shear test apparatus, we have developed a set of equations and a governing model to predict failure mode and force required shearing solid section biomass. Our tests involved multiple cross sectional areas, 3 shear bar designs, and multiple cross sectional shapes.

About the Publication

Lanning, D.N., C. Lanning, J.L. Fridley, J.H. Dooley, M. DeTray. 2008. Mode of failure model for cutting solid section biomass. ASABE Paper No. 085111. ASABE. St. Joseph, MI. 20 pp.

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