Structural Engineering Commons^™

Limited Bandwidth Wireless Communication Strategies For Structural Control Of Seismically Excited Shear Structures, Benjamin Winter

Dissertations, Master's Theses and Master's Reports

Structural control is used to mitigate unwanted vibrations in structures when large excitations occur, such as high winds and earthquakes. To increase reliability and controllability in structural control applications, engineers are making use of semi-active control devices. Semi-active control gives engineers greater control authority over structural response versus passive controllers, but are less expensive and more reliable than active devices. However, the large numbers of actuators required for semi-active structural control networks introduce more cabling within control systems leading to increased cost.

Researchers are exploring the use of wireless technology for structural control to cut down on the installation cost …

Load Estimation, Structural Identification And Human Comfort Assessment Of Flexible Structures, Ozan Celik

Electronic Theses and Dissertations

Stadiums, pedestrian bridges, dance floors, and concert halls are distinct from other civil engineering structures due to several challenges in their design and dynamic behavior. These challenges originate from the flexible inherent nature of these structures coupled with human interactions in the form of loading. The investigations in past literature on this topic clearly state that the design of flexible structures can be improved with better load modeling strategies acquired with reliable load quantification, a deeper understanding of structural response, generation of simple and efficient human-structure interaction models and new measurement and assessment criteria for acceptable vibration levels. In contribution …

Analytical Strip Method For Thin Cylindrical Shells, John T. Perkins

Theses and Dissertations--Civil Engineering

The Analytical Strip Method (ASM) for the analysis of thin cylindrical shells is presented in this dissertation. The system of three governing differential equations for the cylindrical shell are reduced to a single eighth order partial differential equation (PDE) in terms of a potential function. The PDE is solved as a single series form of the potential function, from which the displacement and force quantities are determined. The solution is applicable to isotropic, generally orthotropic, and laminated shells. Cylinders may have simply supported edges, clamped edges, free edges, or edges supported by isotropic beams. The cylindrical shell can be stiffened …

Site Specific Sinkhole Risk Assessment In Central Florida Using Cone Penetrometer Testing, Ryan Shamet

Electronic Theses and Dissertations

As Florida's population is expanding and greater fluctuations in groundwater levels are being recorded, Central Florida has been experiencing a higher frequency of sinkhole occurrences than ever before in recorded history. Sinkholes in Central Florida are formed by a combination of bedrock weathering and overburden soil erosion due to the groundwater recharge and are a part of Florida's past and future geology. The initial stage of a sinkhole is referred to as soil raveling and is the most effective time to perform soil improvement measures, such as grouting, to mitigate further expansion of a subterranean void. Subsurface exploration tests, commonly …

Uav-Based Bridge Inspection And Computational Simulations, Luis Duque

Electronic Theses and Dissertations

The use of Unmanned Aerial Vehicles (UAV), commonly known as drones, has significantly increased in the field of civil engineering due to the poor condition of the United States’ infrastructure. The American Society of Civil Engineers (ASCE) recently reported that more than 9.1% of the United States’ bridges were structurally deficient and required attention and maintenance to ensure appropriate structural performance. Meanwhile, current practices are expensive and unsafe for bridge inspectors, requiring innovative and safer methods for the study of bridges. The goal of this paper was to identify better techniques to not only inspect, quantify, and determine the effect …

Enhancing Ductility Of Wwr Slabs, Mohamed Shwani, Taylor J. Sorensen, Ethan Pickett, Parker Syndergaard, Marc Maguire

Faculty Publications

A series of research studies have recently identified an issue called strain localization in welded wire reinforced (WWR) members. This phenomenon reportedly concentrates strains at welded cross wire locations and severely limit ductility. Those that identified the phenomenon used it to imply that WWR is unsafe because it does not warn of failure. This research program is investigating details to mitigate the strain localization effect and demonstrate the WWR can be used safely. Sixteen beams have been constructed using WWR and rebar with various cross wire spacing, using a realistic design. The strain localization phenomenon was not demonstrated, but WWR …

Investigating Composite Action At Ultimate For Commercial Sandwich Panel Composite Connectors, Salam Al-Rubaye, Taylor J. Sorensen, Marc Maguire

Faculty Publications

To achieve full or partial-composite action in prestressed concrete sandwich panel walls, the engineer must obtain a percent composite action from a connector manufacturer, making some engineers uncomfortable. Engineers are dependent upon the recommendations given by the connector manufacturers to establish their designs. This project tested six full-scale sandwich panel walls to evaluate the percent composite action of various connectors and compare the results to those provided by the composite connector manufacturers. This study concluded that the reported degrees of composite action from each manufacturer are considered conservative in all instances for the connectors tested in this paper. Additionally, the …

Air Injection As A Scour Countermeasure At Bridge Piers, Ravi Teja Reddy Tippireddy

Dissertations, Master's Theses and Master's Reports

Local scour is a major cause of concern for the stability of bridge piers and the safety of the public using the bridges. Structural countermeasures and flow-altering devices have been developed to deal with local scour. Many armoring structural countermeasures are very effective and efficient in clear water conditions but are susceptible to moving bed forms and leaching. The flow-altering devices are effective in both clear water conditions and moving bed forms, but are prone to clogging, less efficient in changing flow direction, etc. This study aims to reduce the local scour by injecting air in order to reduce the …

Detection Of Fatigue Damage In Shear Connections Using Acoustic Wave Propagation, Zichao Wang

Dissertations, Master's Theses and Master's Reports

Fatigue damage is an important concern in structural steel connections where frequent load reversals are expected. Detection of fatigue damage is typically done with infrequent visual inspections that are subjective and limited to surface features. A permanent embedded structural health monitoring (SHM) system could be helpful in detecting damage as it occurs. Current methods for detecting fatigue damage include inference of fatigue life expended through cycle counting from long-term strain measurement campaigns, and through short-term impedance measurements. The first approach has the advantage that it is relatively simple from an algorithmic point of view, but it is an indirect measure …

Numerical Computation Of Transient Response Of 2d Wedge Impact, Naresh Kumar Koyyapu

LSU New Orleans Theses and Dissertations

The diverse applications of advanced marine craft ascribed to their high speed and technological advancements has led to the use of stronger and lighter metals in such crafts. High speed, in effect also increases slamming loads as higher speed increases frequency of wave encounter while operating in waves. The present study is limited to wedge impact models. Fundamentally, the study is thus about two-dimensional (2D) wedge impact in water. In an attempt to predict the structural response to impact hydrodynamic force, a beam element based finite element (FE) computer program is written and the results of the code are presented …

Total Bridge Replacement Of M-13 Over Cheboyganing Creek, Daniel Burns

Honors Theses

The Michigan Department of Transportation sought a proposal consisting of design and construction engineering services for the total bridge replacement of M-13 over Cheboyganing Creek. The M-13 Bridge Project is located on M-13 over Cheboyganing Creek on the Saginaw River in Portsmouth Township, Bay County, Michigan.

Several components of the existing bridge have been rated in poor or serious condition on the National Bridge Inventory rating scale. A total bridge replacement is required and aligns with MDOT strategies to address critical infrastructure needs in the state as well as the Bay Region's five-year plan for managing bridge and culvert infrastructure. …

Expression And The Functional Study Of Fusion Proteins Α-Amylase And Hemolysin- Αas An Application In Biofilm Polysaccharide Degradation, Gede Yuda Sugiarta, Anggoro Wiseso, Siska Yuliana Sari, Etri Dian Kamila, Vanessa Geraldine, Diana Christina, Muhammad Hanifi, Dwiantari Satyapertiwi, Robby Hertanto, Budiman Bela, Masafumi Yohda, Muhamad Sahlan

Makara Journal of Technology

Biofilm is an aggregate of consortium bacteria that adhere to each other on a surface. It is usually protected by the exopolysaccharide layer. Various invasive medical procedures, such as catheterization, endotracheal tube installation, and contact lens utilization, are vulnerable to biofilm infection. The National Institute of Health (NIH) estimates 65% of all microbial infections are caused by biofilm. Periplasmic α-amylase (MalS) is an enzyme that hydrolyzes α-1, 4- glicosidic bond in glycogen, starch, and others related polysaccharides in periplasmic space. Another protein called hemolysin-α (HlyA) is a secretion signal protein on C terminal of particular peptide in gram negative bacteria. …

Design Of The Human Assembly Strategy In A Self-Optimizing Assembly Cell: A Case Study Of Indonesians, Novie Susanto, Ratna Purwaningsih, Kharisma Panca Kurniawati

Makara Journal of Technology

This paper presents a continuing study of the human cognitive aspect application in the technical systems. The last studies design a human-centered design based on the German culture. The result shows a significant difference of human performance between Germans and Indonesians. Therefore, this study examines the human cognitive model based on Indonesian culture to investigate whether the different cognitive model based on the culture aspect can improve the human performance. The study was conducted on 60 people classified by age, young (16-34 years old) and old (older than 34 years old). Participants render predictions on an assembly activity for two …

Optimizing Supply Chain Collaboration Based On Agreement Buyer-Supplier Relationship With Network Design Problem, Wahyudi Sutopo, Ayu Erliza, Arien Heryansyah

Makara Journal of Technology

In recent years, the rising competitive environment with shorter product life cycles and high customization forces industries to increase their flexibility, speed up their response, and enhance concurrent engineering designs. To integrate these prospects, supply chain collaboration becomes a pertinent strategy for industries to strengthen their competitiveness. The network design problem is used to implement supply chain collaboration. In the buying and selling process, sharing information between buyer and supplier are important to obtain a transaction decision. The optimimum supply chain profit can be identified by mathematical model of network design problem. The Mathematical Model takes into consideration the uncertainity …

Effect Of Milling On The Densification Of Sic-Basedcomposites From Polysilazane, Alfian Noviyanto, Toshiyuki Nishimura

Makara Journal of Technology

High density SiC-based composites from polysilazane were fabricated by high energy milling and hot pressing. After cross-linking at 200 °C, the polysilazane was pyrolysed at 1000 °C in N2 for 2 h to form amorphous Si-C-N-O followed by high energy milling for 1 h. Milled amorphous Si-C-N-O was sintered in hot pressing at 1600 and 1700 °C for 1 h in vacuum under the applied pressure of 50 MPa. Although no sintering additives were used, dense SiC-based composites were obtained with this method. Sintered density was 3.04 g/cm3, while only 2.57 g/cm3 for amorphous Si-C-N-O without milling. It is suggested …

Characterization And Utilization Of Calcium Oxide (Cao) Thermally Decomposed From Fish Bones As A Catalyst In The Production Of Biodiesel From Waste Cooking Oil, Aldes Lesbani, Sabat Okta Ceria Sitompul, Risfidian Mohadi, Nurlisa Hidayati

Makara Journal of Technology

Thermal decomposition of fish bones to obtain calcium oxide (CaO) was conducted at various temperatures of 400, 500, 800, 900, 1000, and 1100 °C. The calcium oxide was then characterized using X-ray diffractometer, FTIR spectrophotometer, and SEM analysis. The calcium oxide obtained from the decomposition at 1000 °C was then used as a catalyst in the production of biodiesel from waste cooking oil. Diffraction pattern of the calcium oxide produced from decomposition at 1000 °C showed a pattern similar to that of the calcium oxide produced by the Joint Committee on Powder Diffraction Standard (JCDPS). The diffractions of 2q values …

Thermoeconomic Optimization Of Cascade Refrigeration System Using Mixed Carbon Dioxide And Hydrocarbons At Low Temperature Circuit, Nasruddin Nasruddin, Arnas Arnas, Ahmad Faqih, Niccolo Giannetti

Makara Journal of Technology

Many applications and industrial processes require very low cooling temperature, such as cold storage in the biomedical field, requiring temperature below -80 °C. However, single-cycle refrigeration systems can only achieve the effective cooling temperature of -40 °C and, also, the performance of the cycle will decrease drastically for cooling temperatures lower than -35°C. Currently, most of cascade refrigeration systems use refrigerants that have ozone depletion potential (ODP) and global warming potential (GWP), therefore, in this study, a cascade system is simulated using a mixture of environmentally friendly refrigerants, namely, carbon dioxide and a hydrocarbon (propane, ethane or ethylene) as the …

Developing Road Infrastructure Route Planning: Increasing Feasibility Of Toll Road Project, Mohammed Ali Berawi, Teuku Yuri Zagloel, Perdana Miraj, Abdur Rohim Boy Berawi, Wellsi Titaheluw, Saipol Bari Bin Abd Karim

Makara Journal of Technology

Indonesian government attempts to improve connectivity and to increase regional activities in Sumatera Island through the development of Trans Sumatera Toll Road (TSTR). However, despite its benefits to local economic development in Sumatera, the project shows low feasibility due to a low amount of investment. It can be attributed from the lack of planning in the initial phase to produce a comprehensive route that considers the various potentials of the regions. Thus, this research aims to investigate alternative route planning of Trans Sumatera Toll Road particularly in this paper for Central Sumatera by studying Gross Regional Domestic Product (GRDP), population …

Thermal And -Γ –Ray Irradiation Effects On The Ionic Conductivity Of (Licl)X(Montmorillonite)1-X, Safei Purnama, Aziz Khan Jahja, Takeshi Sakuma

Makara Journal of Technology

Compositesof montmorillonite (MMT) - lithium salts have been prepared using a simple process of powders mixing followed by heating. The powders resulting from this method are expected to beionic conductors with a high ionic conductivity characteristics. This characteristics is also further improved by employing gamma-ray irradiation technique at specified irradiation doses. The best results were obtained for the (LiCl)0.5(MMT)0.5 composite with a room temperature ionic conductivity of 2.192 mS/cm, which then increases to ~5 mS/cm after gamma irradiation at a dose of 400 kGy. This value is equivalent to the value of the ionic conductivity of current commercial rechargeable lithium …

Test Standard For Determining The Fastener-Sheathing Local Translational Stiffness Of Sheathed Cold-Formed Steel Assemblies, 2017 Edition, American Iron And Steel Institute

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

No abstract provided.