Engineering Commons^™

Cold-Formed Steel Lipped Channel Columns Undergoing Local-Distortional-Global Interaction: Experimental And Numerical Investigation, Eliane S. Santos, Pedro Borges Dinis, Eduardo M. Batista, Dinar Camotim

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Experimental and numerical results concerning the post-buckling behavior and strength of fixed-ended cold-formed steel lipped channel columns experiencing interaction involving local, distortional and global buckling (i.e., stemming from the closeness between the critical buckling stresses associated with these three buckling mode types), are reported. After briefly addressing the column specimen geometry selection, the paper presents and discusses the results of an experimental investigation carried out at COPPE, Federal University of Rio de Janeiro (UFRJ, Brazil) and involving 16 columns − its output consists of steel material properties, initial imperfection measurements, equilibrium paths and failure loads/modes. Then, some test results are …

Cold-Formed Steel Channel Sections With Web Stiffeners Subjected To Local And Distortional Buckling — Part I: Tests And Finite Element Analysis, Liping Wang, Ben Young

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

An experimental investigation of simply supported beams with two different stiffened channel sections has been conducted under both four-point bending and three-point bending about the major axis of the sections. Stiffeners were employed to the web of plain channel and lipped channel sections to improve the flexural strength of cold-formed steel sections that are prone to local buckling and distortional buckling. In this study, the channel sections were brake-pressed from high strength zinc-coated grades G500 and G550 structural steel sheets with nominal 0.2% proof stresses of 500 and 550 MPa, respectively. The high strength stiffened channel sections had the thicknesses …

Numerical Studies Of Rivet-Fastened Rectangular Hollow Flange Channel Beams, R. Siahaan, P. Keerthan, M. Mahendran

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The rivet-fastened rectangular hollow flange channel beam (RHFCB) is a new cold-formed hollow section proposed as an alternative to welded hollow flange beams. It is a monosymmetric channel section made by rivet-fastening two torsionally rigid rectangular hollow flanges to a web plate. This method will allow the designers to develop optimum sections, with affordable rivet connection between their web and flange elements. In addition to this unique geometry, the rivet-fastened RHFCBs also have unique characteristics relating to their stress-strain characteristics, residual stresses, initial geometric imperfections and hollow flanges that are not encountered in conventional hot-rolled and cold-formed steel channel sections. …

Section Moment Capacity Tests Of Rivet-Fastened Rectangular Hollow Flange Channel Beams, R. Siahaan, P. Keerthan, M. Mahendran

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The rivet-fastened rectangular hollow flange channel beam (RHFCB) is a new cold-formed hollow section proposed as an alternative to welded hollow flange steel beams. It is a mono-symmetric channel section made by rivet fastening two torsionally rigid rectangular hollow flanges to a web plate. This method will allow the designers to develop optimum sections, with affordable rivet connection between the web and flange elements. The new rivet-fastened RHFCB has unique characteristics that are not encountered in conventional hot-rolled and cold-formed steel channel sections. Therefore an experimental study consisting of 15 section moment capacity tests was conducted with different rivet spacings …

Developments In The Finite Strip Buckling Analysis Of Plates And Channel Sections Under Localised Loading, Gregory J. Hancock, Cao Hung Pham

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Thin-walled sections under localised loading may lead to web crippling of the sections. This paper develops the Semi-Analytical Finite Strip Method (SAFSM) for thin-walled sections subject to localised loading to investigate web crippling phenomena. The method is benchmarked against analytical solutions, Finite Element Method (FEM) solutions, as well as Spline Finite Strip Method (SFSM) solutions.

The Behaviour Of Cold-Formed C-Sections With Square Holes In Shear, Cao Hung Pham, Yu Han Chin, Peter Boutros, Gregory J. Hancock

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Cold-formed structural C-section members may be subjected to axial force, bending and shear or combinations of either two or all of these actions. Design methods for these sections are normally specified in the Australian/New Zealand Standard for Cold-Formed Steel Structures (AS/NZS 4600:2005) or the North American Specification for Cold-Formed Steel Structural Members (2012). Both Effective Width Methods (EWM) and the newly developed Direct Strength Method (DSM) can be used for the design. For shear, the NAS S100 2012 Edition has recently included DSM design rules just for the plain sections only. To date, no rules are presented in this specification …

Experimental Study Of Longitudinally Stiffened Web Channels Subjected Predominantly To Shear, Luciano A. Bruneau, Cao Hung Pham, Gregory J. Hancock

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The Direct Strength Method (DSM) of design of cold-formed sections has recently been extended in the North American Specification for Cold-Formed Steel Structural Members-NAS S100:2012 to include shear. The two new features of the DSM rules for shear researched are the effect of full-section shear buckling as opposed to web-only shear buckling and Tension Field Action (TFA). The prequalified sections in the rules include sections with flat webs and webs with small intermediate longitudinal stiffeners. In order to extend the range to larger intermediate stiffeners as occurs in practice, a series of fourteen shear tests have been performed at the …

Numerical Studies Of Collapse Behaviour Of Multi-Span Beams With Cold Formed Sigma Sections, F. L. Wang, J. Yang, J. Lim

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

Multi-span cold-formed steel beams are widely used for roof purlin and cladding rails due to their high strength to weight ratio and ease of installation on site. There are a wide variety of cross-sectional shapes e.g. C, Z, top hat and sigma sections. A sigma section possesses several advantages such as high cross-sectional resistances and large torsional rigidities compared with standard Z or C sections.

Traditional design methods for cold-formed multi-span steel beams have been based on elastic theory, such as the Effective Width Method (EWM) and the Direct Strength Method (DSM). Both methods ignore the effect of redistribution of …

Development Of A New Beam-Column Design Method For Cold-Formed Steel Lipped Channel Members, Shahabeddin Torabian, Baofeng Zheng, Benjamin W. Schafer

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The structural strength of cold-formed steel lipped channels under combined axial force and biaxial bending moments has been predicted by geometric and material nonlinear collapse analyses performed in ABAQUS and compared to both current, and a newly proposed, beam-column design method. The ABAQUS analyses utilizes a validated modeling protocol calibrated against previous testing by the authors, and including residual stresses and strains, and geometric imperfections; as well as, appropriate cross-section dimensions, member length, and boundary conditions. A total of 75 different lipped channel cross-sections have been selected and the capacity of the beam-column member has been examined under 127 combinations …

Experimental Investigation On Ultimate Capacity Of Eccentrically-Compressed Cold-Formed Beam-Columns With Lipped Channel Sections, Yuanqi Li, Yinglei Li, Yanyong Song

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

This paper is mainly concerned with the in-plane behavior of eccentrically-compressed cold-formed steel beam-columns with lipped channel sections. The tested members are classified into three series by loading types including: axial compression and major axis bending (X), axial compression and minor axis bending (lips in tension, Y1), and axial compression and minor axis bending (lips in compression, Y2). A numerical model is developed and verified by the experimental results. Then the elastic local buckling loads are discussed based on test results, numerical analysis, and design methods. The comparison between test strength and nominal strength obtained by AISI specification indicates that …

Using Graph Visualization To Look At The Trajectories Of Events That Lead To Readmission, Abbas Shojaee, Isuru Ranasinghe, Sudhakar Nuti, Shu-Xia Li, Harlan Krumholz

Yale Day of Data

Information on specific sequence of healthcare utilization events in heart failure patients may be useful for identifying distinct subpopulations of patients with HF. Knowledge of patient trajectories may help to improve prediction of future readmission which can be used to tailor management to the individual needs of the patient.

This research introduces a new approach to mining administrative and clinical datasets by incorporating graph networks to identify & visualize the trajectories of sequences of events.

Surgical Adhesive From Mussel Mimetic Polymer, Jenna Desousa, Cori Jenkins, Jonathan Wilker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Injuries involving damaged tissues are currently repaired through an invasive technique involving the use of screws, plates and sutures as support, which can damage these tissues. The biomedical field currently lacks an adhesive that can replace harmful implants. A surgical adhesive can provide a quick and easy alternative, which will minimize the risk of damaging healthy tissue in surgery. Inspiration for such materials can be found by looking at marine mussels as they are able to stick to nearly any surface, even in wet environments. Marine mussels affix themselves to different surfaces using adhesive plaques consisting of various proteins. Polymer …

A User Study On Route Evaluation, Renjun Zheng, Jieqiong Zhao, David Ebert

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently existing route direction representation like arrow on the route is vastly used and intuitive however it is not guaranteed to meet the requirement of application level use. With many routes overlapping with each other on a map, directions become vague and ambiguous for user to recognize. Route visualization is a vital part of map-related application. We developed several route direction representations to investigate which one performs best when user view the routes on actual map. The shapes we chose for these representations respectively are curve, arrow, triangle, right triangle, and taper. We established a complete mechanism to test route …

Investigation Of The Performance Of Different Types Of Zirconium Microstructures Under Extreme Irradiation Conditions, Eric M. Acosta, Osman J. El-Atwani

The Summer Undergraduate Research Fellowship (SURF) Symposium

The safe and continued operation of the US nuclear power plants requires improvement of the radiation resistant properties of materials used in nuclear reactors. Zirconium is a material of particular interest due to its use in fuel cladding. Studies performed on other materials have shown that grain boundaries can play a significant role on the radiation resistant properties of a material. Thus, the focus of our research is to investigate the performance of different zirconium microstructures under irradiation conditions similar to those in commercial nuclear reactors. Analysis of the surface morphology of zirconium both pre- and post-irradiation was conducted with …

Dynamic Surgical Tool Tracking And Delivery System Using Baxter Robot, Sthitapragyan Parida, Juan Pablo Wachs, Maria Eugenia Cabrera

The Summer Undergraduate Research Fellowship (SURF) Symposium

Several hospitals face nurse staffing shortages for surgeries. This research focuses on building a system with Baxter robot capable of identifying surgical tools using computer vision and delivering them to the surgeon on demand. This would deal with the issue of nurse unavailability during simple surgical procedures. The key aspects of the project were: testing the accuracies of various Artificial Neural Networks (ANNs) in classifying surgical instruments, and programming Baxter to implement a surgical tool delivery system using magnets at the tip of its 7-DOF robotic arms. The methodology consisted of, first, implementing algorithms to enable Baxter to do pick …

Dynamic Analysis Of Granular Battery Assembly, Rohan Dudaney, Waterloo Tsutsui, Weinong Chen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Collisions and impacts are an inevitable reality when it comes to commercial cars and vehicles, but as batteries become more prevalent it is vital to understand how they react dynamically and as a system to better protect both the passengers and toxic chemicals inside of the batteries. One potential solution is to surround these batteries with non-vital tubes that can be sacrificed and help protect the batteries. This study is done to understand the structure of batteries and to test how an assembly of sacrificing cells and batteries reacts in an impact situation to see if there is significant energy …

Catalysis In Petroleum Coking, Robert Khakimov, Anya Heinimann, Enrico Martinez, Hyun-Tae Hwang

The Summer Undergraduate Research Fellowship (SURF) Symposium

The petroleum industry is challenged with the processing of present heavy crudes caused by high composition of sulfur and metals, which lead to a higher yield of unfavorable bottom product as vacuum residue. Vacuum residue is the least valuable fraction of four, such as saturates, aromatics, resins and asphaltenes. However, it can be upgraded to recover more valuable products such as light hydrocarbons. The Delayed Coking process is going to be used to transform the vacuum residue at different experimental conditions. First of all, the behavior of the vacuum residue needs to be analyzed with no additions in feedstock. Secondly, …

Model-Free Method Of Reinforcement Learning For Visual Tasks, Jeff S. Soldate, Jonghoon Jin, Eugenio Culurciello

The Summer Undergraduate Research Fellowship (SURF) Symposium

There has been success in recent years for neural networks in applications requiring high level intelligence such as categorization and assessment. In this work, we present a neural network model to learn control policies using reinforcement learning. It takes a raw pixel representation of the current state and outputs an approximation of a Q value function made with a neural network that represents the expected reward for each possible state-action pair. The action is chosen an \epsilon-greedy policy, choosing the highest expected reward with a small chance of random action. We used gradient descent to update the weights and biases …

Granular Matter: Microstructural Evolution And Mechanical Response, Aashish Ghimire, Ishan Srivastava, Timothy S. Fisher

The Summer Undergraduate Research Fellowship (SURF) Symposium

Heterogeneous (nano) composites, manufactured by the densification of variously sized grains, represent an important and ubiquitous class of technologically relevant materials. Typical grain sizes in such materials range from macroscopic to a few nanometers. The morphology exhibited by such disordered materials is complex and intricately connected with its thermal and electrical transport properties. It is important to quantify the geometric features of these materials and simulate the fabrication process. Additionally, granular materials exhibit complex structural and mechanical properties that crucially govern their reliability during industrial use. In this work, we simulate the densification of soft deformable grains from a low-density …

Building Predictive Chemistry Models, Christopher Browne, Nicolas Onofrio, Alejandro Strachan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Density Functional Theory (DFT) simulations allow for sophisticated modeling of chemical interactions, but the extreme computational cost makes it inviable for large scale applications. Molecular dynamics models, specifically ReaxFF, can model much larger simulations with greater speed, but with lesser accuracy. The accuracy of ReaxFF can be improved by comparing predictions of both methods and tuning ReaxFF’s parameters. Molecular capabilities of ReaxFF were gauged by simulating copper complexes in water over a 200 ps range, and comparing energy predictions against ReaxFF. To gauge solid state capabilities, volumetric strain was applied to simulated copper bulk and the strain response functions used …

Visualizing Mechanics: Educational Videos Demonstrating Core Mechanics Concepts, Camilo Schrader, Jeffrey Rhoads, Charles M. Krousgrill, Stephen Alex Stamm, Elizabeth Bushman

The Summer Undergraduate Research Fellowship (SURF) Symposium

There has been an increased interest in using technology to relay information over the past 20 years. This interest has been reflected in the way the internet has expanded to incorporate nearly-uncountable numbers of blogs, streaming videos, and discussion forums. Recent research has shown that younger generations of students prefer internet-based platforms such as these to communicate and learn, as they are congruent with a visual style of learning. The present study seeks to fuse the predominantly reflective and intuitive methods found in a traditional lecture with the more visual and active modes of learning to provide a larger range …

Optimization Of Acid Production In Food Waste Via Anaerobic Respiration, Charles Daniels, Raymond Red Corn, Abigail S. Engelberth Phd.

The Summer Undergraduate Research Fellowship (SURF) Symposium

According to the Food and Agriculture Organization of the United Nations, one third of all food produced in world is wasted; 1.63 * 10⁹ metric tons of nutrition is lost to transportation, contamination, or neglect every year (FAO 2013). This wasted food, however, could be repurposed as a substrate for microbial conversion into useful chemicals. This research is aimed at finding the optimal conditions for bacterial colonies to generate volatile fatty acids (VFAs): resources that are used as solvents, medicines, and chemical intermediates usually generated from petroleum based resources (Drumright et al., 2000) (Roscher 2000) (Kolt et al., 2007). …

Porphyrin Interaction With Dna-Based Carbon Nanotubes And Regeneration For Light Harvesting, Sawyer E. Morgan, Hanyu Zhang, Jong Hyun Choi

The Summer Undergraduate Research Fellowship (SURF) Symposium

Limitations to current solar cells include the high cost of pure silicon and poor current transfer within cells. An emerging alternative is single-walled carbon nanotubes (SWCNTs), which when combined with DNA and porphyrin chromophores can generate a current when absorbing light. We sought to find a chromophore and conditions that would promote bonding to the SWCNTs and improve light harvesting, while being able to regenerate on the film after being damaged. This was experimentally tested by first making SWCNT films on conducting glass slides. These were then functionalized in solutions of chromophore and spectra were measured to determine the bonding …

Biological Implications Of Satellite Cells For Scaffold-Based Muscle Regenerative Engineering, Maggie R. Del Ponte, Charter Chain, Meng Deng Dr., Feng Yue Dr., Shihuan Kuang Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Satellite cells are anatomically localized along the surface of muscle fibers and have been regarded as a population of muscle-specific progenitors that are responsible for muscle regeneration. In response to muscle injuries, satellite cells are activated to enter the cell cycle, then proliferate and differentiate into mature muscle cells to regenerate damaged myofibers. Unfortunately, this natural repair mechanism is interrupted in conditions such as muscle degenerative diseases or volumetric muscle loss. The function of stem cells is regulated by signals from their local microenvironment which is called the stem cell niche. Current satellite cell-based strategies such as direct cell transplantation …

Using Collagen Binding Poly(N-Isopropylacrylamide) Nanoparticles To Prevent Intravascular Platelet Adhesion And Activation, Anna E. Searle, Alyssa Panitch, James Mcmasters

The Summer Undergraduate Research Fellowship (SURF) Symposium

Balloon angioplasty, the most prevalent non-surgical treatment for Atherosclerosis, damages the endothelial layer of the artery, baring an underlying collagenous layer, which causes platelet adhesion and activation and eventual thrombosis and intimal hyperplasia. Previous work in our lab has used a collagen-binding peptidoglycan, dermatan-sulfate-SILY (DS-SILY), that has been shown to bind to type I collagen and prevent platelet adhesion and activation. Our goal is to fabricate nanoparticle-SILY by cross-linking SILY to a poly(N-isopropylacrylamide) (NIPAm) nanoparticle instead of a DS backbone, while retaining the SILY’s high collagen binding affinity and platelet inhibition capacity observed in DS-SILY. Using a biotin-streptavidin assay, we …

Fiber Length And Orientation In Long Carbon Fiber Thermoplastic Composites, Imad Hanhan, Connor Sullivan, Bhisham Sharma, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

Carbon fiber composites have become popular in aerospace applications because of their lightweight yet strong material properties. The injection molding process can be used to produce discontinuous fiber composites using less time and resources than traditional methods, thereby broadening carbon fiber composites’ applications in different industries. Utilization of longer fibers offers more load carrying capability and superior strength properties for injected molded composites. Since the fiber length and the orientation distribution in Long Fiber Thermoplastics (LFTs) directly affects LFT composites’ material properties, there is a need to study the microstructure of LFTs and characterize fiber length and orientation distributions. Therefore, …

Optimization Of Imaging Parameters To Determine Flow Velocity Using Nanoparticles, Sabrina M. Scalf, Haisheng Yang, Russell P. Main

The Summer Undergraduate Research Fellowship (SURF) Symposium

Microfluidic flow chambers have been developed and used to measure flow at the microscopic level. Nanoparticles can be used to track the fluid flow within the chamber and this allows for accurate velocity measures. Microscope parameters used for experimentation differ across various projects and resources; therefore, there is a need to determine the best combination of settings for the equipment at hand. Once appropriate settings are selected, images of the flow are captured with a confocal microscope and can be analyzed using custom written MATLAB code. A pair cross-correlation function is used to determine where the particles have traveled in …

Continuous Analysis Of Many Internet Connected Cameras, Seth Bontrager, Ahmed Kaseb, Yung-Hsiang Lu

The Summer Undergraduate Research Fellowship (SURF) Symposium

There are many Internet connected cameras from all over the world containing a lot of useful information that goes undiscovered. Traffic cameras could monitor the amount of congestion on the highway. Outdoor cameras could monitor weather conditions and help develop more accurate weather models. Currently there is no common system that brings this camera data and a way to analyze it together. The goal of CAM² is to create a system that lets users easily access this camera data and perform large-scale analysis on it to extract useful information. The structure of the system includes (i) a website that …

Comparison Of The Accuracy Of Traffic Counting Devices, Rodrigo Netto De Souza, Laura Slusher ,P.E.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Traffic counting devices are commonly used by governmental agencies and private companies in order to assess traffic patterns and the level of occupancy of roadway networks. The data provided by these devices normally encompasses traffic volumes, vehicle classes and vehicle speeds, and are used by traffic engineers in the planning, design and operations of transportation systems. An evaluation of the accuracy of these devices is of great importance because traffic management decisions are compromised without qualified data. This research evaluated the performance of two different models of traffic counters, Jamar Technologies’ Radar Recorder and Vaisala’s Traffic Analyzer NC-200, both commonly …

Flow Regime Transition In Trickle Bed Reactors, Eric P. Lehmann, Gregory Honda, Arvind Varma

The Summer Undergraduate Research Fellowship (SURF) Symposium

In industry, trickle bed reactors – fixed beds in which gas and liquid reactants flow concurrently downward through catalyst - are often operated at gas and liquid superficial velocities near the transition boundaries between flow regimes, especially the transition between trickle to pulse flow. Previous studies have characterized flow regime transitions as sharp transitions that occur at single superficial liquid velocities for a fixed superficial gas velocity. In reality, transitions evolve gradually over a range of superficial liquid velocities. Experiments were conducted in a fixed bed with air and water flowing concurrently downward using two different packing media. The transitions …