A well structured computer program has been developed to perform geometrically nonlinear finite element analysis of space trusses and to study the sensitivity of parallel lamella dome under wind and snow loads. The modified Riks/Wempner method is used to perform the prebuckling and postbuckling analysis. The European Convention for Constructional Steelwork (ECCS code) is used as the code of practice for design wind pressures on domes. Failures of domes have occurred during snow storms and have attributed to heavy local snow concentrations. Most codes of practice do not provide design wind and snow loads for domes, and a few international codes do show significant differences in the distributions of design wind pressure for domes. Moreover, current design practices for domes do not reflect the possibility of heavy local snow concentrations. Since wind load data is widely varied among the codes, and specific information on local snow concentrations is not available, the study of the behavior of a full-size lamella dome under different wind pressures and various snow distributions will be carried out with the finite element analysis, and critical load combinations will be obtained with the aid of stability boundary. The proposed study is expected to provide guidelines for the determination of critical wind and snow load conditions. / M.S.

A linear analysis of a commercial aluminum lattice dome was performed with the loads prescribed by the American National Standards Institute. The pressure snow loads were transformed into a distributed load along the dome members. The analysis of the dome was performed with the structural analysis program STAAD-III. The dome was modeled as a space frame with the joint member stiffness range from pinned-end to four times the member stiffness. The internal forces in the pinned-end and framed-end models were compared to the specifications by the Aluminum Association. The pinned-end model under the unbalanced snow load were found to exceed the allowable. The maximum deflection occurred when the joint stiffness was one-half of the member stiffness. The maximum axial force occurred when the joint stiffness was four times the member stiffness. The maximum moment at the midpoint of the member occurs when the member ends are pinned. / Master of Science

Virginia's Smart Road, to be completed by early 2000, is a test bed for numerous research activities including snow and ice control, remote sensor testing, snow removal management, safety and human factors, and vehicle dynamics. An all-weather testing system will feature 75 automated snowmaking towers. In order to provide timely and repeatable weather scenarios, equipment operators will need to understand fully the limitations and capabilities of the snowmaking system. The research presented herein addresses the hydraulic and hydrologic variables and design methodology to implement efficient snowmaking at a transportation research facility. Design variables include nozzle configuration, water pressure and flowrate, compressed air pressure and flowrate, tower orientation, snow inducer concentration, water and compressed air temperature, and ambient weather conditions. Testing and data collection was performed at the Snow Economics, Inc. research and development site at Seven Springs Mountain Resort in Champion, PA. The results of this work will be used to guide the operators of the Smart Road on the most efficient use of the snowmaking equipment. / Master of Science

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