Off-Centered Cavity Impact on Stem Strength
University Outreach Publication
<br /><br /> One aspect of hollow stem assessments for strength loss involves various forms of stem crosssectional area damage. One of the scenarios often cited but seldom determined is a stem which has a cavity of a given diameter, but the cavity is not centered in the middle of the stem. This publication will look at one means of estimating relative strength of a stem with a closed, off-centered cavity. This publication is a simple theoretical review of complex and dynamic mechanisms associated with the tree, soil, and environment. This publication is intended to assist tree specialists better appreciate tree biomechanics.<br /><br /> Off-centered cavity stem strength values are dependant upon the thinnest portion (smallest radial thickness) of the ring of wood surrounding the cavity, and the size of the cavity. A stem with a large cavity with thick walls is only slightly weaker than a solid stem. A relatively small cavity with thin enclosing wood walls can make the tree weaker than a solid stem. Compressive faulting in the thinnest wall area is a common form of catastrophic failure in stems with large diameter cavities. Figure 1 provides a graphical definition of these calculations.<br /><br /> Tree Biomechanics Series<br /><br /> FOR00-020<br /><br />
Dr. Kim D. Coder
2005
Warnell School of Forestry and natural Resources, University of Georgia
Athens, GA
3
FOR00-020
Biology (tree), Disaster, Evaluation/Assessment, Mechanics (tree), Plant Health Care, Risk Assessment and Hazard, Safety Issues, Storms, Structure (tree)
National, Southeast, International
mechanics, Leaf characteristics, biomechanics, statics, risk assessment