Date of Award

12-2014

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Civil Engineering

Advisor

Dr. Sez Atamturktur

Committee Member

Dr. Brandon Ross

Committee Member

Dr. Weichiang Pang

Abstract

In the summer of 2013, a steel roof deck manufacturer (Company A) approached Clemson University about testing their steel roof decking product to evaluate the performance of the steel roof deck to resist impact from tornado windborne debris using FEMA P-361 Design and Construction Guidance for Community Safe Rooms. To assist Company A in better serving their customers in areas prone to severe wind events and to facilitate use of their products in community safe rooms, debris impact tests were conducted on two cold-formed corrugated steel roof decking products. Community safe rooms are buildings that are constructed in accordance with the guidance provided in FEMA P-361, to provide `near-absolute' protection for the occupants within the safe room. The term `near absolute' protection pertains to the idea that the safe rooms are built according to the current knowledge of extreme wind events and offer the occupant a high probability of being protected from injury or death. Impact damage from windborne debris can lead to dramatic increases in the net pressure acting on the building envelope during severe wind events and can lead to major envelope and structural damage. Accordingly, impact resistance is a critical feature of safe rooms and is one of the criteria addressed in FEMA P-361. To satisfy FEMA P-361 criteria, the entire safe room envelope (walls, doors, roof, etc...) must be resistant to debris impact. This means that the safe room envelope is capable to resist windborne debris perforation and does not become damaged beyond a given threshold in order to provide the occupant with a life-safety level of protection from windborne debris. Following the prescribed testing procedure referenced by FEMA P-361, impact resistance of the roof deck specimens were evaluated experimentally by 'shooting' test specimens with a 2 x 4 (nominal 1.5' x 3.5') wood board. The speed of the 2 x 4 wood boards varied from 56 miles per hour (mph) to 67 mph. A pneumatic air cannon was designed and built for firing the missiles at repeatable and consistent velocities. Also, a steel reaction frame was designed and built to support the specimen while testing was being conducted. The impact testing procedures strictly followed those referenced by FEMA P-361 and ICC-500 For the Design and Construction of Storm Shelters. The finite element analysis program ANSYS v. 15.0 was implemented to further examine the nonlinear behavior of the corrugated metal decking under impact loading. Availability of this model makes it possible to evaluate deck performance for a variety of factors including but not limited to changes in deck size, corrugated cross-sectional geometry, boundary conditions, material properties, missile velocity, and impact location. The use of this model will bring insight into the mechanics of the impact and help predict how the decking will react in other impact loading scenarios.

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