Engineering Commons^™

Vibration Coupling In Continuous Belt And Band Systems, C. D. Mote, W-Z Ben Wu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Small transverse oscillation of an endless band supported by wheels couples the response of the free spans of the band to oscillation of the wheels. The coupling arises from the finite curvature of the free spans of the band when its bending stiffness is finite. Significant modeling error can occur if a single span of the band is modeled as a simply supported, axially moving beam. The coupling provides an opportunity to dissipate vibration energy. Experiments and finite element analyses support the coupling discussion presented. © 1985 Academic Press Inc.

Load And Resistance Factor Design Of Cold Formed Steel Comparative Study Of Design Methods For Cold Formed Steel, Lan-Cheng Pan, Wei-Wen Yu, Brian K. Snyder

CCFSS Library (1939 - present)

Allowable Stress Design is the current method used to design cold-formed steel structural members and connections. In this design approach, factors of safety are used to compute the allowable design stresses which are compared to the actual maximum stresses that will occur in the member during the life of the structure. In recent years, the Load and Resistance Factor Design (LRFD) method has been developed for the design of hot-rolled steel shapes and the design of cold-formed steel structural members. This method is based on probabilistic and statistical techniques to account for the many uncertainties involved with the actual design. …

Design Of Automotive Structural Components Using High Strength Sheet Steels - Results And Evaluation Of Stub Column Tests For Unstiffened Curved Elements, Wei-Wen Yu, M. Brad Parks

CCFSS Library (1939 - present)

I. INTRODUCTION A. GENERAL In the past few years, a dramatic increase in the use of high strength sheet steels in automobiles has been brought about by the demand for improved fuel economy and safety of motor vehicles. Many of the automotive structural components, which are made of high strength sheet. steels, consists either partially or totally of curved elements. Therefore, it was decided to include an investigation into the structural behavior of curved elements as a part of a research project entitled, "Structural Design of Automotive Structural Components Using High Strength Sheet Steels." The research project began in early …

Load And Resistance Factor Design Of Cold-Formed Steel Revised Tentative Recommendations - Load And Resistance Factor Design Criteria For Cold-Formed Steel Structural Members With Commentary, Wei-Wen Yu, Theodore V. Galambos

CCFSS Library (1939 - present)

The "Allowable Stress Design Method" has long been used for the design of cold-formed steel structural members. The "Load and Resistance Factor Design Method" has recently been developed from a research project sponsored by American Iron and Steel Institute. In this method, separate load and resistance factors are applied to specified loads and nominal resistance to ensure that the probability of reaching a limit state is acceptably small. These factors reflect. the uncertainties of analysis, design, loading, material properties and fabrication. They are derived on the basis of the first order probabilistic methodology as used for the development of the …

Comparison And Evaluation Of Web Crippling Prediction Formulas, Monique Bakker, Teoman Peköz

CCFSS Library (1939 - present)

Since the use of end and load stiffeners is frequently impractical in thin-walled cold-formed steel construction, the webs of beams a.nd deck oay cripple due to the high local intensity of the load or reaction. In this report three different web crippling prediction formulations are compared with experimental results from five different sources. It is found that these web crippling formulas show considera.ble differences and do not give satisfactory results consistently.

Biofilm Growths With Sucrose As Substrate, Ju-Chang Huang, Shoou Yuh Chang, Yow Chyun Liu, Zhanpeng Jiang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study was conducted to: (1) Evaluate the effect of DO on cell yield in a fixed film reactor using 1,000 mg/L sucrose as a substrate; (2) evaluate the correlations of the biofilm thickness and density with DO and their resultant substrate stabilization rates; and (3) examine the response of biofilm communities as a result of DO and biofilm thickness changes. Data obtained from this study indicate that DO has only a minor effect on the cell yield. However, the thickness of aerobic biofilm is definitely related to DO, or thickness (mm) = (2.08 x DO)/(9.2 + DO). The biofilm …

Length-Thermal Stress Relations For Composite Bridges, Jack H. Emanuel, Charles M. Taylor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Computer-assisted analysis was used to study the relation among uniform, linear, and nonlinear stress components thermally induced in a composite bridge section for hypothetical parameters of varying span lengths, number of spans, and support conditions, as well as for actual bridges. The results were verified by conventional methods of analysis. The following was concluded for prismatic (constant) sections: (1) For constant proportionality of span lengths, each of the three thermal stress components is independent of span length; (2) variation of the proportionality of span lengths affects only the linear stress component; (3) support reactions and deflections caused by thermal loading …

Relative Durability Of Shale -- A Suggested Rating System, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The inability to predict the degradation tendencies of shale has resulted in numerous failures of projects where shale was used as a construction material. Because shale does not fit neatly into either a soil category or a rock category, the tests that are commonly used to classify soil or rock are in many instances not totally suitable for classifying shale as to its long-term behavior properties. Thus, special classification tests of shale types has become necessary. The durability or shale relates to how well it can withstand its changing environment and still retain its initial properties. Strength, expansion characteristics, and …

Development Of Apparatus For Constant-Hydraulic-Gradient And Constant-Rate-Of-Strain Consolidation Tests, Jack F. Geerlings

Masters Theses

"A back pressure type consolidometer manufactured by Anteus Laboratory Equipment Company is modified to perform either constant hydraulic gradient or constant rate of strain consolidation tests. The modification of the consolidometer and its instrumentation are described. Computer software is developed for the purpose of apparatus control and for test data acquisition and analysis.

Constant hydraulic gradient and constant rate of strain consolidation tests are performed on samples consolidated from a slurry in the laboratory. Results of these tests are compared with incremental consolidation tests performed with an oedometer.

The modified apparatus was found to be suitable for use in both …

A Theoretical Study Of Antecedent Soil Moisture As It Relates To The Rainfall-Runoff Relationship, Karen Sue Angert

Masters Theses

"This paper addresses the feasibility of using antecedent soil moisture as a tool for predicting the extractions from rainfall due to the infiltration process by solving the one-dimensional equation for saturated- unsaturated flow through porous media. Soil moisture characteristics in the form of empirical equations were used to incorporate the hysteretic behavior of the soil-water relationships into the model. Two sets of parameters were developed to be representative of a silty sand and a silty fine sand.

Extractions as infiltration from a given storm hyetograph and the total volume of direct runoff were computed for different initial moisture states. When …

The Effect Of The Degree Of Saturation On The Permeability Of A Compacted Clay To Organic Permeants, Mark Alan Harms

Masters Theses

"Relationships for permeability of kaolinite versus degree of saturation and permeability versus flow are developed for 0.005 N calcium sulphate, xylene and aniline permeants using the triaxial flexible wall permeameter. The clay was statically compacted at degrees of saturation of 50%, 75% and 100%. A gradient of 277 was used for the permeability tests.

The initial degree of saturation was inversely related to the permeability of the clay. Saturated clay samples were found to be virtually impervious to aniline and xylene. As the degree of saturation decreased, the permeability increased with the initial volume of flow equivalent to the volume …