Engineering Commons^™

Computationally Modeling The Human-Structure Interaction Response Of An Occupied Cantilevered Structure, Brennan Smith

Honors Theses

There is a limited understanding of the impact that passive human occupants have on a dynamic structural system, referred to as Human-Structure Interaction (HSI). Cantilevers are naturally prone to excessive vibrations due to their long unsupported spans, and cantilevered structures such as those commonly found in the seating area of a stadium facility or concert hall are designed to support a high density of occupancy.

This study determined that HSI in cantilevered structures can be modeled using a simple two-degree-of-freedom system. The results of the model were validated by data that was collected on a small-scale laboratory structure intentionally designed …

Performance Of Fouled Railroad Superstructure Subjected To Traversing Heavy Haul Trains, Majid Kh Touqan

Electronic Thesis and Dissertation Repository

Railway transportation offers capacity, efficiency, and safety to serve the needs of modern societies for moving freight and people. Therefore, the sustainability and safety of railroad infrastructure are of paramount importance for securing transportation needs. Freight train passby loads increase the surface deformation of railroad substructure due to cumulative plastic strains, which lead to surface deviation of the railroad tracks. Correspondingly, railroad maintenance is necessary to sustain track geometry alignment and to prevent deterioration of the sub-structure over time, which can increase operating costs significantly. Therefore, this thesis evaluates the performance of fouled railroad superstructure through laboratory testing of fouled …

Development Of An Analytical Method For Design Of Electromagnetic Energy Harvesters With Planar Magnetic Arrays, Mohsen Amjadian, Anil K. Agrawal, Hani H. Nassif

Civil Engineering Faculty Publications and Presentations

In this paper, an analytical method is proposed for the modeling of electromagnetic energy harvesters (EMEH) with planar arrays of permanent magnets. It is shown that the proposed method can accurately simulate the generation of electrical power in an EMEH from the vibration of a bridge subjected to traffic loading. The EMEH consists of two parallel planar arrays of 5 by 5 small cubic permanent magnets (PMs) that are firmly attached to a solid aluminum base plate, and a thick rectangular copper coil that is connected to the base plate through a set of four springs. The coil can move …

Energy Harvesting For Self-Powered Sensors For Smart Transportation Infrastructures, Anil K. Agrawal, Mohsen Amjadian, Hani Nassif

Civil Engineering Faculty Publications and Presentations

In this research project, an Electromagnetic Energy Harvesting System (EMEHS) is developed for harvesting the kinetic energy of ambient and traffic-induced vibrations and carry out a detailed feasibility study and impacts of such system for application on transportation infrastructures. The proposed EMEHS utilizes the innovative concept of creating array of large number of small permanent magnets through certain optimization criteria to achieve strong and focused magnetic field in a particular orientation. When these magnets are attached to a flexible sub-system and placed close to the copper coil, ambient and traffic-induced vibration of the sub-system induces eddy current in copper the …

Seismic Response Mitigation Of Base-Isolated Buildings, Mohammad Hamayoun Stanikzai, Said Elias, Rajesh Rupakhety

Civil & Environmental Engineering Faculty Publications

Earthquake response mitigation of a base-isolated (BI) building equipped with (i) a single tuned mass damper at the top of the building, (ii) multiple tuned mass dampers (MTMDs) at the top of the building, and (iii) MTMDs distributed on different floors of the building (d-MTMDs) is studied. The shear-type buildings are modeled by considering only one lateral degree of freedom (DOF) at the floor level. Numerical approach of Newmark's integration is adopted for solving the coupled, governing differential equations of motion of 5- and 10-story BI buildings with and without TMD schemes. A set of 40 earthquake ground motions, scaled …

Characterization Of Vibration Effects On The Internal Structure And Strength Of Regular And High Strength Recycled Concrete, Jovanca Smith, Rekha Rampit, R. Parey

International Conference on Durability of Concrete Structures

There is a need for more in depth understanding of the consolidation effect of concrete on its durability, especially in tropical climates. During placement of fresh concrete in molds vibration is required to prevent quality problems such as honeycombs and desegregation. Nevertheless, precise monitoring of concrete vibration time has been avoided by construction professionals. This results in concrete durability reduction of appropriately designed concrete due to variation in aggregate settlement, air void content and change in water to cement ratio. In this study, the effects of vibration time on concrete strength, aggregate segregation, and physical properties were experimentally investigated on …

Decision-Making Tool For Road Preventive Maintenance Using Vehicle Vibration Data, Changbum Ahn, Chao Wang, Jing Du

Data

Corresponding data set for Tran-SET Project No. 18PLSU08. Abstract of the final report is stated below for reference:

"Automated and timely road pavement damage inspection is critical to the preventive maintenance and the long-term sustainability and resilience of roads in Region 6. Current road inspection practices rely heavily on a manual process. Sensor-based methods (e.g., LiDAR scanning) are promising but can be too expensive for a wider adoption. This study employs a crowdsourcing approach of using the vibration patterns of regular vehicles in inferring specific types of road damages. A cloud-based smart phone app and system was developed to collect …

Decision-Making Tool For Road Preventive Maintenance Using Vehicle Vibration Data, Changbum Ahn, Chao Wang, Jing Du

Publications

Automated and timely road pavement damage inspection is critical to the preventive maintenance and the long-term sustainability and resilience of roads in Region 6. Current road inspection practices rely heavily on a manual process. Sensor-based methods (e.g., LiDAR scanning) are promising but can be too expensive for a wider adoption. This study employs a crowdsourcing approach of using the vibration patterns of regular vehicles in inferring specific types of road damages. A cloud-based smart phone app and system was developed to collect real-time vehicle vibrations, location data, and road damage images for training the detection model. However, there is a …

Investigation And Proposed Remedy Of Vibration Problem In Industrial Crane System Due To Human Operation, Dustin C. Lorance

Civil Engineering Theses

A recent investigation of a crane system began when a facilities manager reported a runway beam under-going torsional vibration during operations. The investigation revealed the runway beam’s twisting was caused by resonance vibration due to “inching” of the crane hoist. A Fourier spectrum analysis revealed that one of the harmonic frequencies of this rhythmical motion coincided very close to the natural frequency of the crane system. The runway beam, although met strength requirements, failed to meet serviceability criteria due to the resonance vibration. Resonance vibration issues due to human activity in crane operation (inching, sway, etc.) is often encountered by …

Acoustic And Dynamic Characteristics Of A Complex Urban Turnout Using Fibre-Reinforced Foamed Urethane (Ffu) Bearers, Sakdirat Kaewunruen

Sakdirat Kaewunruen

A special track system used to divert a train to other directions or other tracks is generally called ‘railway turnout’. A traditional turnout system includes rails, switches, crossings (special track components), steel plates, fasteners, screw spikes, timber bearers, ballast and formation. The wheel rail contact over the crossing transfer zone has a dip-like shape and can often cause detrimental impact loads on the railway track and its components. The large impact also emits disturbing noises (either impact or ground-borne noise) to railway neighbors. In a brown-field railway track where an existing aged infrastructure requires renewal or maintenance, some physical constraints …

Vibration Reduction Of Offshore Wind Turbines Using Tuned Liquid Column Dampers, Colin Roderick

Masters Theses 1911 - February 2014

Offshore wind turbines (OWTs) are becoming an accepted method for generating electricity. The environmental conditions of offshore locations often impose high wind and wave forces on OWTs making them susceptible to intense loading and undesirable vibrations. One method to reduce system vibrations is through the use of structural control devices typically utilized in civil structures. Tuned liquid column dampers (TLCDs) show great promise in the application to OWTs due to their high performance and low cost. This thesis examines the use of TLCDs in OWTs.

Equations of motion for limited degree-of-freedom TLCD-turbine models are presented. A baseline analysis of each …

Evaluation Methods For Health Monitoring Of Aerospace Structure Rotary Joints, Sergio Armando Navarro

Open Access Theses & Dissertations

In September 2007, the excessive vibrations played a significant role in the station operation since one of the rotary joints, which provides the station electrical energy, presented an anomaly. The replacement of its bearing components and re-lubrication were necessary to reduce the problem. To avoid a new anomaly, the inspection of the rotary joints performance continues by using the accelerometers data. This thesis presents three new approaches to monitor the vibrations at the International Space Station based on Root-Mean-Square, kurtosis, and Approximate Entropy (ApEn). MATLAB functions and codes were necessary to implement the three monitoring techniques results from the provided …

Viscosity Effects In Vibratory Mobilization Of Residual Oil, Igor A. Beresnev, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The last decade has seen clarifications of the underlying capillary physics behind stimulation of oil production by seismic waves and vibrations. Computational studies have prevailed, however, and no viscous hydrodynamic theory of the phenomenon has been proposed. For a body of oil entrapped in a pore channel, viscosity effects are naturally incorporated through a model of two-phase core-annular flow. These effects are significant at the postmobilization stage, when the resistance of capillary forces is overcome and viscosity becomes the only force resisting an oil ganglion's motion. A viscous equation of motion follows, and computational fluid dynamics (CFD) establishes the limits …

Closed Course Testing Of Portable Rumble Strips To Improve Truck Safety At Work Zones, Steven D. Schrock, Yong Bai

Mid-America Transportation Center: Final Reports and Technical Briefs

The purpose of this research was to compare the attention-getting characteristics, movements and vertical displacements of several portable, reusable rumble strips. The attention-getting characteristics and displacement were measured after passes of a fully loaded heavy truck and a passenger vehicle. Sound and vibration tests revealed that the portable plastic rumble strips were more effective on cars than trucks for generating in-vehicle vibration and increasing in-vehicle sound levels. Further, they were generally better able to match the characteristics of the tested permanent rumble strip compared to the adhesive rumble strips, and that this was also true for the configurations that contained …