Engineering Commons^™

Biomechanics Of Trees Under Extreme Wind Loading Events, Mojtaba Dargahi

Electronic Thesis and Dissertation Repository

For urban planners, arborists and foresters, understanding tree stability under self-weight and applied loads from wind and snow is important when developing management strategies to reduce the risk of damage from these abiotic agents. Current predictive approaches are generally empirical and based on a posteriori surveys of failures. A more rigorous engineering approach to understanding response phenomenon in trees subjected to extreme winds has been attempted herein. The size of trees and their architecture (shape and structure) greatly influence their mechanical stability under dynamic loading. Considering trees as porous media, wind loads on them are affected by their resistance to …

Steel Compression Members With Partial-Length Reinforcement, Morgan Herrell

Electronic Thesis and Dissertation Repository

Steel wide-flange columns in existing truss bridges may be built-up with flange cover plate reinforcement to increase compressive capacity. This thesis investigates the use of partial-length steel cover plates about column mid-height to improve the weak-axis buckling resistance.

The present research first reviews literature concerning the Euler buckling of members with partial-length reinforcement. Inelastic buckling is simulated by 3-D finite element analysis accounting for cover plate length, cover plate area, bolt hole perforations, yield stresses, residual and locked-in dead load stresses, and initial out-of-straightness. The model is validated by a load test of a full-scale column with bolted reinforcement plates. …