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Full-Text Articles in Engineering

Decision-Making Tool For Road Preventive Maintenance Using Vehicle Vibration Data, Changbum Ahn, Chao Wang, Jing Du Aug 2019

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 Aug 2019

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 …


An Experimental And Computational Investigation Of Rotating Flexible Shaft System Dynamics In Rotary Drilling Assemblies For Down Hole Drilling Vibration Mitigation, Richard Duff Jan 2013

An Experimental And Computational Investigation Of Rotating Flexible Shaft System Dynamics In Rotary Drilling Assemblies For Down Hole Drilling Vibration Mitigation, Richard Duff

LSU Doctoral Dissertations

Rotary drilling system vibration has long been associated with damaging the bit, the bottom hole assembly (BHA) and drill string. Vibration has been traditionally measured in the bottom hole assembly, and been closely associated with the resonant behaviors.

This research study proposes an improved physical laboratory model to explore the dynamic behaviors associated with vibration. This model includes contact with the borehole wall allowing a range of stabilization geometries while removing bit-formation interaction effects. The results of exercising the model help develop new insights into both vibration measurement diagnostics and mitigation strategy execution.

Presented here is a review of other …


Optimal Actuation In Active Vibration Control Using Pole-Placement, Carla Ann Guzzardo Jan 2012

Optimal Actuation In Active Vibration Control Using Pole-Placement, Carla Ann Guzzardo

LSU Doctoral Dissertations

The purpose of this study was to find and demonstrate a method of optimal actuation in a mechanical system to control its vibration response. The overall aim is to develop an active vibration control method with a minimum control effort, allowing the smallest actuators and lowest control input. Mechanical systems were approximated by discrete masses connected with springs and dampers. Both numerical and analytical methods were used to determine the optimum force selection vector, or input vector, to accomplish the pole placement, finding the optimal location of actuators and their relative gain so that the control effort is minimized. The …


Dynamic Characterization Of Vocal Fold Virbrations, Zhenyi Wei Jan 2012

Dynamic Characterization Of Vocal Fold Virbrations, Zhenyi Wei

LSU Doctoral Dissertations

An emerging trend among voice specialists is the use of quantitative protocols for the diagnosis and treatment of voice disorders. Vocal fold vibrations are directly related to voice quality. This research is devoted to providing an objective means of characterizing these vibrations. Our goal is to develop a dynamic model of vocal fold vibration, and map the parameter space of the model to a class of voice disorders; thus, furthering the assessment and diagnosis of voice disorder in clinical settings.

To this end, this dissertation introduces a new seven-mass biomechanical model for the vibration of vocal folds. The model is …


State Feedback Control With Time Delay, Akshay Nareshraj Singh Jan 2009

State Feedback Control With Time Delay, Akshay Nareshraj Singh

LSU Doctoral Dissertations

In this thesis we start with an introduction to the theory of vibration control. We broadly classify the control methods into passive and active schemes. We introduce the problem of state feedback control and provide the classical solution in the form of Ackermann formula. We then identify the limitations of the classical approach and present the more elegant solution of partial pole assignment without spillover. We highlight the problem with model uncertainties and describe the method of pole assignment using data from measured receptances. This approach is extended for pole assignment for a linear vibrating system by using state feedback …


System Identification Of Bridge And Vehicle Based On Their Coupled Vibration, Lu Deng Jan 2009

System Identification Of Bridge And Vehicle Based On Their Coupled Vibration, Lu Deng

LSU Doctoral Dissertations

Most current techniques used for system identification of bridges and vehicles are static-test-based methods. Methodologies that can use bridge dynamic responses or modal information are highly desirable and under development. This dissertation aims to develop new identification methodologies for bridge-vehicle systems using the bridge dynamic responses and modal information. A new bridge model updating method using the response surface method (RSM) was proposed in this dissertation. The RSM was used to design experiments in order to find out the relationships between the bridge responses and parameters to be updated. Results from numerical simulations and a field study show that the …


Eigenvalue Optimization And Its Applications In Buckling And Vibration, Srinivas Gopal Krishna Jan 2007

Eigenvalue Optimization And Its Applications In Buckling And Vibration, Srinivas Gopal Krishna

LSU Doctoral Dissertations

Eigenvalue problems are of immense interest and play a pivotal role not only in many fields of engineering but also in pure and applied mathematics. An in-depth understanding of this class of problems is a pre-requisite for vibration and buckling analyses of structures. Design optimization of structures to prevent failure due to instability (bucking) and vibration introduces the problem of determining optimal physical parameters such that load carrying capacity or the fundamental natural frequency is maximized. A classical example of such problems is the Lagrange problem of determining the shape of the strongest column against buckling. The primary objective of …


The Spectral Conforming Model And Its Applications, Jaeho Shim Jan 2004

The Spectral Conforming Model And Its Applications, Jaeho Shim

LSU Doctoral Dissertations

It has been observed that finite element or finite difference model of order can approximate with fair accuracy less than one-third of the eigenvalues of the underlying continuous system corresponding to the low spectrum. The new discrete model, namely the spectral conforming model, is developed to predict the eigenvalues of continuous systems in both the low and high spectra. The spectral conforming models are developed using an inverse vibration method. The classical vibration problem is the direct method. In the direct approach, the characteristic behaviors of the system, i.e. frequency response, natural frequency, and steady state response are analyzed and …


The Transcendental Eigenvalue Problem And Its Application In System Identification, Kumar Vikram Singh Jan 2003

The Transcendental Eigenvalue Problem And Its Application In System Identification, Kumar Vikram Singh

LSU Doctoral Dissertations

An accurate mathematical model is needed to solve direct and inverse problems related to engineering analysis and design. Inverse problems of identifying the physical parameters of a non-uniform continuous system based on the spectral data are still unsolved. Traditional methods, for the system identification purpose, describe the continuous structure by a certain discrete model. In dynamic analysis, finite element or finite difference approximation methods are frequently used and they lead to an algebraic eigenvalue problem. The characteristic equation associated with the algebraic eigenvalue problem is a polynomial. Whereas, the spectral characteristic of a continuous system is represented by certain transcendental …