Mechanical Engineering Commons^™

Comparision Of Fillet-Welded Base Plate Fatigue Design For Highway Support Structures With Laboratory Research Tests, William Shea

Williams Honors College, Honors Research Projects

There are many types of vertical structures along highways that serve unique purposes. These structures include traffic signs for directing, warning, or regulating traffic, luminaires for distributing and directing light, traffic signals supporting equipment such as traffic lights, and combination structures including any combination of the aforementioned structures. Highway support structures are typically fabricated from steel or aluminum and are designed to the guidelines and specifications of the AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals. The structures are connected to a foundation by anchor bolts through a welded base plate. Often a cause …

Application Of Survival Analysis Techniques To Probabilistic Assessment Of Fatigue In Steel Bridges, Azam Nabizadehdarabi

Theses and Dissertations

The fatigue of engineering materials under repetitive loading is a significant issue affecting the design and durability of components and systems in a variety of engineering-related applications including civil, mechanical, aerospace, automotive, and electronics. Many factors can affect the service life of a component or system under repetitive loading, such as the type of structure, loading, connection details, stress state, peak stress or stress range, surface condition, temperature, and environmental exposure. Currently, there is no comprehensive probabilistic approach that can systematically address all the factors that contribute to fatigue on a single mathematical platform. However, advanced analysis techniques developed for …

Fatigue Of Drill Pipes Used In Horizontal Directional Drilling, Feibai Ma

Doctoral Dissertations

Fatigue is the most common cause of mini-HDD drill rod failure. It can occur at stress levels far below the normal operating stress in most drill stem components. Fatigue failures occur because the drill rod, after it has been forced into a curved path, undergoes a cyclic bending stress oscillating from tension to compression in concert with the other stress components caused by torque, thrust, or pullback.

When a rod breaks underground, there is considerable extra cost caused by the delay in “fishing” out the broken rod as well as the cost of replacing the rod. On the other hand, …