http://hdl.handle.net/2142/234 http://hdl.handle.net/2142/14281 Joint Shear Behavior of Reinforced Concrete Beam-Column Connections subjected to Seismic Lateral Loading Kim, Jaehong LaFave, James M. Beam-column connections have been identified as potentially one of the weaker components of reinforced concrete moment resisting frames subjected to seismic lateral loading. Well-established knowledge of RC joint shear behavior is necessary because severe damage within a joint panel may trigger deterioration of the overall performance of RC beam-column connections or frames. However, despite the importance of understanding RC joint shear behavior, a consensus on the ways in which some parameters affect joint shear strength has not been reached. In addition, there has generally been no accepted behavior model for RC joint shear stress vs. joint shear strain. Therefore, in this research a more systematic understanding of RC joint shear behavior has been achieved by completing the following tasks: construction of an extensive experimental database, characterization of RC joint shear behavior, and development of RC joint shear strength models and proposed joint shear behavior models. An extensive experimental RC beam-column connection database (of 341 subassemblies in total) was constructed and classified by governing failure mode sequence, in-plane geometry, outof- plane geometry, and joint eccentricity. All included subassemblies were made at a minimum of one-third scale, and all used conventional types of reinforcement anchorages. RC joint shear behavior was described as an envelope curve by connecting key points displaying the most distinctive stiffness changes. The first point indicates initiation of diagonal cracking within a joint panel, the second point results from yielding of reinforcement, and the third point corresponds to maximum response. An RC joint shear strength model was then developed using the experimental database in conjunction with the Bayesian parameter estimation method. A simple and unified joint shear deformation model (at maximum response) was also developed, following the same procedure used to develop the simple and unified joint shear strength model. Full RC joint shear behavior models were constructed by employing the Bayesian method at each key point and also by adjusting the simple and unified joint shear strength and deformation models for maximum response. Finally, the Parra-Montesinos and Wight model was modified to improve its reliability by updating the key relation between principal strain ratio and joint shear deformation. reinforced concrete connections joint shear failure experimental database earthquake loading Bayesian parameter estimation structural behavior prediction models http://hdl.handle.net/2142/14280 Decentralized Strategies for Monitoring Structures using Wireless Smart Sensor Networks Sim, Sung-Han Spencer, Jr., Billie F. Driven by the needs to address problems with our rapidly aging civil infrastructure, structural health monitoring (SHM) has arisen as an important tool to improve maintenance and operation. Introduced as a promising alternative to the traditional wired sensors, wireless smart sensors offer unique features (low cost, wireless communication, onboard computation, and small size) that enable deployment of dense array of sensors essential for assessing structural damage. The centralized data collection approach, which the wired sensor system commonly employs, is not suitable to wireless smart sensor networks (WSSNs) due to limitations in the wireless communication; decentralized data aggregation and processing is required in the WSSNs. Rather than collecting uncondensed raw sensor data at a centralized location, in-network data processing, made possible by the onboard computational capability of smart sensors, is utilized to condense the raw data and extract meaningful information. By transferring only the condensed data to the centralized location, data communication over the wireless links can be greatly reduced. Decentralized data aggregation approaches can be placed in two broad categories: (a) independent processing (each node processes sensor data independently), and (b) coordinated processing (sensor nodes collaborate to process sensor data by sharing information). This report outlines the implementation of both decentralized data aggregation approaches for the WSSNs employing Crossbow’s Imote2 smart sensor platform. Design considerations for developing WSSN applications are described herein, including network-wide flow and timing, fault-tolerant feature, and network topology to account for the decentralized data aggregation. WSSN applications introduced in this report can be downloaded at the Illinois SHM Project website (http://shm.cs.uiuc.edu). structural health monitoring wireless smart sensor wireless smart sensor network decentralized processing ISHMP Services Toolsuite Imote2 http://hdl.handle.net/2142/14276 Exact Solutions of Some Dynamic Problems of Indentation And Transient Loadings of an Elastic Half Space Thompson, J.C. Robinson, A.R. Impact Potential theory (Mathematics) Wave equation Boundary value problems http://hdl.handle.net/2142/14275 Decision Table Formulation of The 1969 Aisc Specification Fenves, S.J. Gaylord, E. H. Goel, S.K Building, Iron and steel --Standards --United States. Decisions logic tables. http://hdl.handle.net/2142/14274 Strength and Behavior of Prestressed Concrete Vessels for Nuclear Reactors-Volume II Paul, S.L. Zimmer, Alan Gotschall, H.L. Matson, R.H. Karlsson, B.I. Mohraz, B. Sozen, M.A. Prestressed Concrete Reactor Vessel Program http://hdl.handle.net/2142/14273 Numerical Analysis of ELastic Plates and Shallow Shells By an Integral Equation Method Forbes, D.J. Robinson, A.R. The object of this investigation is to develop a numerical method for determining the static displacements and stresses in certain elastic plates and shells based on an integral equation formulation of the boundary value problem. The basic singular solutions used are those of plane stress in elasticity and of the theory of flexure of plates. In accordance with these theories, the plate or shell is assumed to be thin or of medium thickness and is composed of homogeneous, isotropic elastic material. It is also assumed that the displacements and rotations are small, so that linear theories are applicable; that is buckling is not considered. Integral equations Boundary value problems --Numerical solutions Elastic plates and shells http://hdl.handle.net/2142/14271 Distributed of Stresses and Partition of Loads in Gusseted Connections Birkemore, P.C. Eubanks, R.A. Munse, W.H. Load partition and stress distribution in riveted and bolted structural joints are two associated behavioral phenomena which have received continued attention from structural researchers and designers in an attempt to understand better the behavior of multiply fastened joints and to design them adequately. This study presents a basic analysis of various physical parameters and their effects on load partition and stress distribution in gussested connections. The gusseted connection under investigation is a particular type of riveted or bolted connection which has additional variables associated with the shape and size of the gusset plate. Analytical and experimental studies were conducted concurrently to justify the conclusions as well as study the assumptions made in arriving at the analytical models. Analytically, two elastic joint problems were studied: (1) the attachment of tension member by a single row of fasteners to a semi-infinite plate, (2) the similar attachment to a symmetrical tapered gusset plate. The parameters studied include the number of fasteners, the fastener pitch, the edge distance of fasteners, the fastener and tension member flexibilities, and thickness and geometry of the plate. The member to plate connections were evaluated in terms of the load partition among the fasteners as well as the stress distribution at various locations in the plate. It was found that, individually, many of the joint parameters did not appreciably affect the load partition in the connection; however, cumulatively they could have detrimental effects. One parameter, the edge distance severe stress conditions at the edge of plate on the line of loading. The finite geometry plate, studied experimentally, was fabricated and tested with variable geometry or taper of the gusset plate;the plate was loaded by lap plated connected by tight fitting pins. The elastic stress distribution was studied using brittle lacquer techniques and electrical resistance strain gages at specific locations on the gusset. Individual fastener loading was measured using a special technique involving the placement of strain gages on the gusset near the loaded pins. The load partition of the pinned joint was examined for five geometries and variable numbers of fasteners. Geometry did not appreciably affect the load partition until extreme geometries, which resulted in a change of the gusset net cross-sectional area, were reached. Joints (Engineering) --Testing. Strains and stresses http://hdl.handle.net/2142/14262 Final Reprot Low Cycle Fatigue of HY-130 (T) Butt Welds Radziminski, J.B. Lawrence, F.V Mukai, S. Panjwani, P.N. Johnson, R. Mah, R. Munse, W.H. A preliminary evaluation of the axial fatigue behavior of plates and transverse butt-welded joints in HY-130(T) steel is presented. The weldments were prepared using each of two experimental "second-generation" GMA welding wires and a coated electrode. Fatigue tests were conducted using both sound weldments and weldments containing various internal defects, including porosity, slag, lack of fusion, and lack of penetration. Radiographic and ultrasonic testing techniques were used to study the initiation and propagation of fatigue cracks originating at internal weld flaws. The fatigue studies have indicated that although the highest standards of quality may be used in the fabrication of HY-130(T) welded joints, it has not been possible to guarantee the elimination of all defects which have proven to be critical sites for internal fatigue crack nucleation under axial loading. Internal failures were as likely to occur in specimens rated as sound weldments under radiographic inspection as in weldments having regions containing readily detected flaws. Fatigue cracks originating at internal defects were found to initiate at approximately twenty to eighty percent of the total cyclic life-time of butt-welded joint, for tests conducted at a stress cycle of zero-to-tension. Within the normal limits of scatter for fatigue data, however, the number of cycles of crack propagation to failure beyond the point of internal initiation was found to be reasonably consistent at a specific test stress level, for weldments containing various types and percentages of weld defect area. Crack propagation Fatigue cracks Fatigue -- Testing Weldments http://hdl.handle.net/2142/14261 Regional Data Archiving and Management for Northeast Illinois Dhanaraju, Sharan; Ouyang, Yanfeng; Tursun, Umit Deniz This project studies the feasibility and implementation options for establishing a regional data archiving system to help monitor and manage traffic operations and planning for the northeastern Illinois region. It aims to provide a clear guidance to the regional transportation agencies, from both technical and business perspectives, about building such a comprehensive transportation information system. Several implementation alternatives are identified and analyzed. This research is carried out in three phases. In the first phase, existing documents related to ITS deployments in the broader Chicago area are summarized, and a thorough review is conducted of similar systems across the country. Various stakeholders are interviewed to collect information on all data elements that they store, including the format, system, and granularity. Their perception of a data archive system, such as potential benefits and costs, is also surveyed. In the second phase, a conceptual design of the database is developed. This conceptual design includes system architecture, functional modules, user interfaces, and examples of usage. In the last phase, the possible business models for the archive system to sustain itself are reviewed. We estimate initial capital and recurring operational/maintenance costs for the system based on realistic information on the hardware, software, labor, and resource requirements. We also identify possible revenue opportunities. A few implementation options for the archive system are summarized in this report; namely: 1. System hosted by a partnering agency 2. System contracted to a university 3. System contracted to a national laboratory 4. System outsourced to a service provider The costs, advantages and disadvantages for each of these recommended options are also provided. regional data archive, traffic operations, northeast Illinois http://hdl.handle.net/2142/14260 Cost-Effectiveness and Performance of Overlay Systems in Illinois Volume 1: Effectiveness Assessment of HMA Overlay Interlayer Systems Used to Retard Reflective Cracking Al-Qadi, Imad; Buttlar, William; Baek, Jongeun; Kim, Minkyum This project evaluated the ability of interlayer systems used in HMA overlays to retard reflective cracking. Field crack surveys and forensic investigation, including video imaging and ground penetrating radar surveys as well as laboratory testing of cored specimens, were conducted to examine the behavior of reflective cracking and reflective cracking control systems applied in Illinois. Crack extent and severity were recorded at 24 locations across Illinois. The performance evaluation focused on five types of interlayer systems: area- and strip-type nonwoven fabric; two strip-type composite; and a fine, high polymer content HMA interlayer system. Two reflective cracking indices were developed to characterize the condition of HMA overlays regarding reflective cracking as well as transverse cracking. In addition, a performance benefit ratio parameter, PBR, was developed to assess the performance of treated pavements relative to control sections. The study provided a quantitative assessment for various types of reflective cracking interlayer systems. In addition, it provides a means to predict the performance of several interlayer systems under various vehicular and environmental loading conditions through a simple ESALs-TL chart. A companion report (volume 2) provides tools for the selection of appropriate reflective crack control treatments based upon traffic, climate, and life cycle costs using a user-friendly life cycle cost analysis program (CIND – Cost-effective INnterlayer system Decision program). reflective cracking, crack control, interlayer, HMA overlay