Engineering Commons^™

Development Of Finite Element Techniques To Simulate Concrete-Filled Fiber-Reinforced Polymer Tube Structures, Hakeem S. Majeed

Electronic Theses and Dissertations

This dissertation presents the development of finite-element (FE) techniques to simulate the behavior of concrete-filled fiber reinforced polymer (FRP) tubes (CFFTs) in support of more effective structural design and analysis methods for buried composite arch bridges (BCABs) that use CFFT arches as main structural members. The research includes three specific topics to make contributions in different aspects of the investigation of these complex structures.

The first topic is the nonlinear three-dimensional FE modeling of steel-free CFFT splices. For model validation, comparisons were made between the model predictions and control beam and spliced beams with and without internal collars tested by …

Development Of A Hybrid Thermoplastic Composite And Concrete Deck System, Benjamin T. Smith

Electronic Theses and Dissertations

Reinforced concrete is a widely used structural system in conventional construction. It is used to create beams, columns, slabs, walls, bridge decks, dams, and many other structures. Concrete is a relatively inexpensive material that is much stronger in compression than in tension. This leads to the need to combine concrete with other materials to make an efficient hybrid structure. In conventional construction, steel reinforcing bars (rebar) are often used to carry the tension in the structure, as they are widely available and their design is well understood. There are some situations where rebar is not effective such as highly corrosive …

Design And Predicting Performance Of Carbon Nanotube Reinforced Cementitious Materials : Mechanical Properties And Dispersion Characteristics., Mahyar Ramezani

Electronic Theses and Dissertations

Recently, Carbon Nanotubes (CNTs) are drawing considerable attention of researchers for reinforcing cementitious materials due to their excellent mechanical properties and high aspect ratio (length-to-diameter ratio). However, CNTs might not disperse well within the cement matrix, resulting in little improvement or even degradation of concrete properties. The uncertainty in producing the consistent results in different studies might be attributed to multiple interactions between the experimental variables affecting the nanotube dispersion and the final properties of CNT-cement nanocomposites. Therefore, this research mainly focused on proposing equations that can reliably capture these interactions in order to correlate CNT dispersion with the mechanical …

Point Cloud Technology For Analysis Of Existing Structures, Jacob Cano

Electronic Theses and Dissertations

For this thesis, a study was completed on two different structures on the UCF Orlando campus through the use of both structural plans and point cloud technology. The results sought to understand the viability of point cloud technology as an accurate tool for the static and dynamic modal analysis of existing structures. For static analysis, a portion of the framing of Spectrum Stadium was rendered, modeled, analyzed and compared to a previous case study. The results emphasized how different users can render dissimilar member sizes and lengths due to human judgment on point cloud visuals. The study also found that …

Investigation Of Flexural Behavior Of Steel Fiber Reinforced Concrete And Steel Fiber Orientation Control During Construction, Maria Kolisnichenko

Electronic Theses and Dissertations

Concrete is the most widely used construction material in the world, and its consumption has been increasing. The main benefits of concrete include its durability, availability of the components, and great strength in compression. Despite all these advantages, however, concrete is a brittle material with a relatively low tensile strength and deformation capacity. It is, therefore, vulnerable to cracking under tension, which can lead to sudden catastrophic failures of concrete structures. In order to control and reduce cracking, reinforcement of concrete is necessary.

The most commonly used reinforcement technique in structural application is the use of deformed steel bars. However, …

Field And Numerical Study For Deteriorating Precast Double-Tee Girder Bridges, Brian Kidd

Electronic Theses and Dissertations

Two deteriorating DT bridges in South Dakota, both over 30-years old, were field tested with a static and dynamic load. From the recorded strain values, the liveload distribution factors (LLDFs) and dynamic load allowance (IM) factors were calculated. The AASHTO LRFD and AASHTO Standard Specifications were compared with the field LLDFs and IMs. It was determined that the AASHTO LRFD Specifications were conservative for deteriorating DT girder bridges, with two exceptions. The AASHTO Standard codified LLDFs were significantly higher than the field LLDFs in all cases. The AASHTO LRFD and AASHTO Standard specifications were conservative when calculating the IM factors …

Enhanced Concrete Bridge Assessment Using Artificial Intelligence And Mixed Reality, Enes Karaaslan

Electronic Theses and Dissertations

Conventional methods for visual assessment of civil infrastructures have certain limitations, such as subjectivity of the collected data, long inspection time, and high cost of labor. Although some new technologies (i.e. robotic techniques) that are currently in practice can collect objective, quantified data, the inspector's own expertise is still critical in many instances since these technologies are not designed to work interactively with human inspector. This study aims to create a smart, human-centered method that offers significant contributions to infrastructure inspection, maintenance, management practice, and safety for the bridge owners. By developing a smart Mixed Reality (MR) framework, which can …

Finite Element Modeling Of Mechanically Stabilized Earth Walls Built With Welded Wire Wall Panels, Dejuan G. Solan

Electronic Theses and Dissertations

In this thesis, a finite element modeling of Mechanically Stabilized Earth (MSE) walls using welded wire wall panels was performed. The implementation of finite element modeling and analysis proved to be quite efficient in simulating the three-dimensional behavior of wall panels that are a part of MSE walls. The comprehensive finite element model included defined concrete and steel material properties in order to present both the realistic behaviors of each component in the model as well as better facilitating and increasing the accuracy of the simulation of numerous finite element analysis (FEA) cases. FEA was employed to simulate welded wire …