Structural Engineering Commons^™

Simulation Of Non-Homogeneous Wind Processes, Comparison Between Numerical And Experimental Model Of A Bridge, Héctor Hernández Landero

Electronic Thesis and Dissertation Repository

The scaled aerodynamic model of a bridge is often tested in the boundary layer wind tunnel laboratory (BLWTL). In this study a numerical model of the Baluarte Bridge subjected to wind loading is investigated. The scaled full bridge aerodynamic model was previously studied at the University of Western Ontario, Canada. For the numerical model a finite element model (FEM) is implemented, and the characterization of the buffeting forces are considered on the frequency and time domain. In the former case, the so-called pseudo excitation method is used to characterize the wind load, while in the latter the spectral representation method …

Application Of Acoustic Emission Technology In Monitoring Corrosion Induced Expansion Cracks Of Reinforced Concrete, Zhen Zeng, Gang Xu, Rui Zhang, Zewen Yang

International Conference on Durability of Concrete Structures

Acoustic emission (AE) technology is used to monitor the whole process of reinforced concrete rust expanding and cracking, and the accuracy of AE technology to distinguish the location and type of cracks in concrete rust expanding and cracking is studied and verified. The results show that the protective layer is accompanied by a large number of acoustic emission signals in the process of rust expansion and cracking, Moment tensor inversion can more accurately identify crack sources such as shear source, tensile source and mixed source; In the process of corrosion-induced expansion cracking, shear source cracks appear before tensile source cracks …

An Energy Dissipating Seismic Connector For Precast Concrete Shear Walls, Mohammed Aljuboori, Habib Tabatabai

Civil and Environmental Engineering Faculty Articles

In this study, several steel connector shapes were analytically evaluated as potential new seismic energy dissipating devices between vertical precast concrete shear wall panels. Based on the results of analytical and experimental studies, a multiple yield zone (MYZ) connector is proposed due to its improved performance (in energy dissipation) when compared to the conventional U-shaped flexure plate (UFP) device. Unlike the UFP, the MYZ connector provides stiffness and energy dissipation in both horizontal and vertical directions. The response of a shear wall building system utilizing the MYZ or UFP connectors was evaluated using a simplified frame model. The MYZ connector …

Ultrasonic Ndt Methods For The Evaluation Of Post-Tensioned Systems With Flexible Fillers, Denis Mcdonald

Doctoral Dissertations and Master's Theses

Non-destructive evaluation of post-tensioned structures with flexible fillers is desperately needed due to their rapid implementation in the State of Florida, primarily in roadway structures. This study provides an overview of existing evaluation methods for traditional post-tensioned structures with cementitious grouts and further explores two promising methods to be applied to flexible filler systems. The first method, diffuse ultrasound spectroscopy, indirectly evaluates posttensioned structures by quantifying the severity of microcracking in the structure. Microcrack detection is accomplished by processing received waveforms generated with a pitch-catch transducer configuration. The second method, coda-wave interferometry, measures the velocity variation at the tail end …

Contracting Strategies: A Different Approach To Address Long-Term Performance, Maria Calahorra-Jimenez

Mineta Transportation Institute Publications

For cost-efficiency, public safety, and sustainability, improving long-term performance in highway projects is imperative for public administrations. Project delivery and procurement methods provide an opportunity to align design and construction processes with this goal. While previous studies have explored whether project delivery methods impact the long-term performance of highway projects, these studies did not focus on how core elements within project procurement relate to long-term performance. Thus, to fill this gap, this research explores how and to what extent long-term evaluation criteria are considered in design-build best-value procurement of highway projects. To this end, the team conducted content analysis on …

Structural Dynamics Of Awt-27 Wind Turbine Blade, Amr Ismaiel

Future Engineering Journal

Wind energy is one of the world’s current leading renewable energy resources. One of the major aspects of studying wind turbines is the structural dynamics for the turbine structure including blades and support structure. In the current work, the blades of the Advanced Wind Turbine (AWT-27) are investigated in a dynamic approach. Different wind fields have been generated for the study to provide different Design Load Conditions (DLCs). Three laminar wind velocities of 5 m/s, 12 m/s, and 17 m/s were simulated. Turbulent wind flow fields have also been generated at the three standard classes A, B and C of …

Sage Garden Pavilion Shade Structure, Anthony Razouk Karroum, Manuel Bermudez, Matthew Kilbride, Sarah Holt, Marisa Martineau

Architectural Engineering

Form finding, testing, and construction of funicular double-layered shells in an interdisciplinary format with a focus on designing a shade structure for the San Luis Obispo Botanical Garden Children’s Pavilion. In the process, challenges such as connection design, materiality, storage, and more are explored and refined in relation to shell structures.

Dynamic Response Of Elastic Two-Story Steel Moment Frame Scaled Structure Equipped With Viscous Dampers, Garrett L. Barker, Alexander L. Poirier

Architectural Engineering

The authors of this report are Architectural Engineering undergraduate students at California Polytechnic State University, San Luis Obispo. Damping is a complex, experimentally derived value that is affected by many structural properties and has a profound effect on the dynamic response of structures. Deducing the inherent damping of a steel moment frame and affecting the damping ratio with viscous dampers are two topics explored in this paper. Dampers are commonly implemented in resilient structures that perform better in a design basis earthquake, reducing the seismic cost and downtime. Undergraduate coursework does not delve into the factors that affect damping and …

Increasing Strength Of Plywood Shear Walls, Elizabeth Claypool, Michelle Dennin

Architectural Engineering

In a recent iteration of an upper-division engineering design lab course at Cal Poly SLO, students were challenged to identify and understand the probable failure mechanism of conventionally built plywood shear walls and hypothesize how they could delay or prevent common failure mechanisms to increase the overall lateral load capacity. After observing the results of a test on a conventional, code specified wall, a solution to integrate metal gauge strapping into edge nailing was developed to address the common failure mechanisms of nail head pull through and panel edge tear out. A shear wall with metal strapping installed between the …

Guidelines For The Eeri Seismic Design Competition, Kate Robinson

Architectural Engineering

The Earthquake Engineering Research Institute (EERI) has been dedicated to exposing undergraduate students to the wide range of interdisciplinary subjects related to earthquake engineering through the Seismic Design Competition. In 2022, California Polytechnic State University, San Luis Obispo (Cal Poly) sent 14 students to Salt Lake City, Utah for the competition – to compete with 31 other teams who all tackled the competition problem statement uniquely. The 2022 team was tasked with the research, design, analysis, and construction of a new structure to be built in downtown Salt Lake City, with the goal of replicating the design sequence of real-world …

Shallow-Water Wind Turbine Foundation, Andrew Walker, Nico Nani, James Cusanelli, Zachary Dunkelberger

Mechanical Engineering

Over the 2021-2022 academic year, we, the Shallow Water Wind Turbine Foundation senior project team, designed, manufactured, and tested a fixed bottom, sand mounted turbine foundation for the Cal Poly Wind Power Club’s Collegiate Wind Competition turbine. The foundation was restricted to certain material, installation, and geometric constraints outlined in this report, and needed to support the turbine under operating conditions including 22 m/s wind speeds. The design was analyzed using primarily a bearing capacity geotechnical analysis to determine final geometry and weight. The foundation was then manufactured using welded, custom carbon steel parts.

The foundation was inspected for geometric …

Design, Fabrication, And Testing Of Mechanical Hinges With Snap-Fit Locking Mechanisms In Rigid Origami Structures, Colby James Scanlon

Master's Theses

The ancient art of ‘origami’ has recently become the source of inspiration for engineers to create structures that can unfold from a compact state to a fully deployed one. For instance, researchers have currently adopted origami designs in various engineering disciplines, including aerospace engineering, robotics, biomedical engineering, and architecture. In particular, architects have been interested in designing origami-inspired rigid walled structures that can be deployed as disaster-relief shelters. This type of design has three main advantages: transportability, constructability, and rigidity. Although there has been increased interests in deployable structures, limited research has been conducted on evaluating their structural performance, specifically …

Utilization Of Steel Slag In Development Of Sustainable And Durable Concrete., Karthik Prabhu T Dr, Gowri Shankar M Mr., Jagadesh P Dr., Nagarajan V Dr.

International Journal of Advanced Technology in Civil Engineering

This paper reflects the results of an experimental investigation of the strength, permeability, abrasion, carbonation, and shrinkage characteristics of concrete containing various percentages of steel slag as partial replacement of natural fine aggregates. M 30 Grade concrete was designed as per specific national specifications. Steel slag was used to replace natural sand in the range of 0– 50%. It was observed that the steel slag blended concrete with up to 50% substitution exhibited a comparable compressive and flexural strength when compared to the control specimens. From the Dorry’s abrasion test, it was noted that the specimens could be implemented in …

Experimental And Numerical Investigation Of 3d-Printed Viscoelastic Dampers, Mohammed Jaradat

Civil Engineering ETDs

Elastomeric materials are extensively used in energy dissipation applications to mitigate large lateral displacements and attenuate vibrations. One way of exploiting the capabilities of elastomeric materials is using shear-damping mechanisms such as viscoelastic damping devices (VEDs).

In this research the freedom of design offered by additive manufacturing technology is utilized to produce 3D printed elastomeric parts that act as the viscoelastic layer in an energy damping device. A mechanically interlocked viscoelastic damper (MIVED) with a jigsaw-like interlocking mechanism was designed and manufactured. MIVED is composed of a rigid and soft phase. It operates in two modes, modes I and II, …

Enhancing The Performance Of Dowel Type Fasteners And A Case Study Of Timber Truss Failure, Lon A. Yeary

Theses and Dissertations

This document will outline the findings of three separate and independent studies: Study 1: In or around 1972, an experimental building was constructed. One of the intents of the construction project was to demonstrate advancements in wood building construction design. It was value-engineered throughout. That is, its materials and systems were intended to function at or near design capacity. In 2019, part of the roof of the structure collapsed. This case study investigates two potential factors that led to the failure: stress concentration in excess of the 12 allowable stress for 2 × 4 web members and insufficient plywood sheathing …

Joining Methods For Continuous Fiber Reinforced Thermoplastic Composites In Structural Applications, Andrew Moran

Electronic Theses and Dissertations

Continuous fiber reinforced thermoplastic (CFRTP) composites have been proposed as an alternative to metals in structural applications. CFRTP composites can be used to create structures that are lighter weight, have better resistance to environmental factors, and have the potential to be recycled. However, one of the main challenges to CFRTP composites is connections between structural members. The goal of this thesis is to investigate the feasibility of joining CFRTP composites to both similar and dissimilar materials through literature review, coupon testing, design of a structural joint, and a small scale laboratory prototype of the joint. To achieve this goal the …

The Living Breakwaters Pdr Efforts: Conceptual Scheduling, Calvin O. Walters Jr.

Publications and Research

On October 29, 2012, Superstorm Sandy caused nearly $19 billion in damages in New York City including 69,000 residential units across the five boroughs. This disaster precipitated a post-disaster-rebuilding (PDR) project including roughly $4.2 billion in a Community Development Block Grant allocated towards PDR projects. A portion of the grant was used to construct a living breakwater in Tottenville, Staten Island, consisting of a resiliency approach to risk reduction through erosion prevention, wave energy attenuation, and enhancement of ecosystems and social resiliency to improve resistance to storms for the community of Tottenville. The ridges of each breakwater are designed with …

Integration Of Material Characterization, Thermoforming Simulation, And As-Formed Structural Analysis For Thermoplastic Composites, Philip M. Bean, Roberto A. Lopez-Anido, Senthil Vel

Civil Engineering Faculty Scholarship

An improved simulation-based thermoforming design process based on the integration of material characterization and as-formed structural analysis is proposed. The tendency of thermoplastic composites to wrinkle during forming has made simulation critical to optimized manufacturing, but the material models required are complex and time consuming to create. A suite of experimental methods has been developed for measurement of several required properties of the molten thermoplastic composite. These methods have the potential to enhance thermoplastic composites manufacturing by simplifying and expediting the process. These material properties have been verified by application to thermomechanical forming predictions using commercial simulation software. The forming …

Non-Destructive Evaluation Of Concrete Using Electrical Resistivity And Ultrasonic Wave Propagation, Justin Harris

Electronic Theses and Dissertations

With the intent to investigate the relationship between concrete physical properties and non-destructive evaluation techniques (NDE), several experiments were performed. Specimens were made at varying geometries using a range of different concrete mixes under several different curing conditions. These specimens were subjected to a combination of electrical resistivity and ultrasonic wave propagation measurements. One part of this study investigated determining the orientation of steel fibers using electrical resistivity. This resulted in the fabrication of a four-probe square device with the potential capabilities of determining fiber orientation. The other part of this research applied ultrasonic wave propagation via through-transmission along with …

Structural Design For Fire Conditions Of A Prototype Metal Building Using The New Proposed Appendix To Aisi S100, Xia Yan, Thomas Gernay

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

Performance-based design for fire conditions has been increasingly adopted for different structural systems over the last decade. The objective of this project is to exemplify through a case study how the newly proposed Appendix 4 to AISI S100 [1] on ‘Structural Design for Fire Conditions’ could be used by the metal building industry. The scope of work on the project includes the following:

(1) Identification of a prototype metal building to serve as an exemplar case study for the structural fire design procedure.

(2) Definition of the performance objectives and design requirements for the building in the fire situation. This …