Master of Sciences (Engineering), Case Western Reserve University, 2019, Civil Engineering

Tornadoes are hazards of low probability of occurrence and high consequences that cost the United States billions of dollars each year. Electric power distribution systems are susceptible to damage due to tornadoes with the utility poles being the most vulnerable components. Additionally, the reliability of power distribution systems can be affected by the deterioration of the strength of utility poles with age. Many utility companies nowadays are considering the use of steel and prestressed concrete poles instead of wood poles, which are the most widely used in the United States. Up to date, very few studies have been performed to study the behavior of power networks when subjected to tornadoes. This research proposes a framework to perform reliability analysis, cost analysis, and target hardening of power distribution systems subjected to tornado hazard. It also offers a framework to compare the reliability of wood, steel, and prestressed concrete utility poles subjected to tornadoes through fragility analysis considering the deterioration of the strength of the poles with age.

Committee: Yue Li (Advisor); Xiong Yu (Committee Member); Michael Pollino (Committee Member) Subjects: Civil Engineering

MS, University of Cincinnati, 2016, Medicine: Industrial Hygiene (Environmental Health)

Traditionally, industrial hygienists' methods for identifying risks were limited and not systematic in nature. Industrial hygienists relied on their expertise and their judgment for identifying hazards, and for prioritizing risks in a workplace. Today, many tools are available to the risk assessor. Two experienced certified industrial hygienist's (CIH) traveled to Monument Chemical to take part in a risk assessment study to determine if tools such as checklist and quantitative exposure assessments are beneficial in the identification of risk and the prioritization of chemical hazards. The CIH's observed 25.7 percent of the same hazards while performing their walk through surveys of the areas. 74.3 percent of the hazards identified by one CIH was missed by the other. Categories were established to determine the difference in hazard identification. CIH 1 identified mostly piping systems, while CIH 2 identified mostly hazardous chemical exposures. The CIH's rankings without using a risk assessment tool seemed to more closely resemble each other than the I.H. specialist's rankings using a qualitative exposure assessment tool. Exposure sampling data from Monument was utilized as the metric for “true exposure”. A hazard index was calculated from this data to compare to expert judgment rankings. Without any statistical analysis it is hard to determine whether the CIH's or the tool more closely resemble the ranking provided by the sampling data. However, differences in rank order were noted between the ranking tool and the expert judgments. This study demonstrates that having a checklist helps investigators remain cognizant of the details of a working area. However, if that checklist lacks certain hazard categories the investigator may not extend their surveillance outside of the checklist bounds. This study also demonstrates that using a quantitative tool to prioritize risks is systematic and consistent; however future research could include additional empirical sampling d (open full item for complete abstract)

Committee: Glenn Talaska Ph.D. (Committee Chair); Thomas Lentz Ph.D. (Committee Member) Subjects: Environmental Health

Doctor of Philosophy, The Ohio State University, 2006, Industrial and Systems Engineering

The safety of the American workplace has improved dramatically over the past 30 years. This improvement is directly correlated with the adoption and enforcement of OSHA regulations (OSHA, “OSHA Facts”). However, despite the great strides that have been achieved, some industry sectors continue to produce unnecessarily high numbers of serious and preventable injuries. Machine-related injuries are responsible for nearly half of the thousands of amputation injuries that occur each year. Most machine injuries are preventable through known methods that are well documented. For most machines, OSHA provides guarding and operational requirements that are very general and broadly applicable. However, in the case of mechanical power presses the codes are quite specific and intended to address the specific hazards associated with such presses. This study proposes that the OSHA codes related to mechanical power presses are adequate and address most of the guarding concerns, but employers often fail to comply with the codes, apparently out of a lack of understanding of their implementation. It is hypothesized that an effective tool to help guide personnel through the evaluation of press safety hazards will improve the likelihood of an individual in accurately identifying press hazards. Based on the perceived need, a software tool was developed to assist in the hazard identification process. This tool was tested experimentally to determine its effectiveness. The hazard evaluation performance of a software-assisted group of novices was compared with the performances of a peer group and a group of press professionals, both comparison groups using traditional evaluation methods (specifically ANSI B11.TR3). Each of the experimental groups evaluated three different mechnical power presses. The hazards identified by each experimental group were to address the specific requirements of the applicable OSHA codes for guarding of mechanical power presses (29CFR1910.212 and 29CFR1910.217). Th (open full item for complete abstract)

Committee: Gary Maul (Advisor) Subjects:

Doctor of Philosophy, University of Akron, 2016, Civil Engineering

Self-centering concentrically braced frame (SC-CBF) systems have been developed to increase the drift capacity of braced frame systems prior to damage to reduce post-earthquake damages in braced frames. However, due to special details required by the SC-CBF system, the construction cost of an SC-CBF is expected to be higher than that of a conventional CBF. While recent experimental research has shown better seismic performance of SC-CBF system subjected to design basis earthquakes, superior seismic performance of this system needs to be demonstrated for both structural and nonstructural components in all ground motion levels and more building configurations. Moreover, Stakeholders would be attracted to utilize SC-CBF if higher construction cost of this system can be paid back by lower earthquake induced losses during life time of the building. In this study, the seismic performance and economic effectiveness of SC-CBFs are assessed and compared with CBF system in three building configurations. First, probabilistic demand formulations are developed for engineering demand parameters (inter-story drift, residual drift and peak floor acceleration) using results of nonlinear time history analysis of the buildings under suites of ground motions. Then, Seismic fragility curves, engineering demand (inter-story drift, peak floor acceleration and residual drift) hazard curve and annual probabilities of exceeding damage states are used to evaluate and compare seismic performance of two systems. Finally, expected annual loss and life cycle cost of buildings are evaluated for prototype buildings considering both direct and indirect losses and prevailing uncertainties in all levels of loss analysis. These values are used evaluate economic benefit of using SC-CBF system instead of CBF system and pay-off time (time when the higher construction cost of SC-CBF system is paid back by the lower losses in earthquakes) for building configurations. Additionally, parametric study is per (open full item for complete abstract)

Committee: Qindan Huang Dr. (Advisor); Qindan Huang Dr. (Committee Chair); David Roke Dr. (Committee Member); Craig Menzemer Dr. (Committee Member); Akhilesh Chandra Dr. (Committee Member); Hamid Bahrami Dr. (Committee Member) Subjects: Civil Engineering; Economics; Engineering; Finance; Mechanical Engineering