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Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Civil and Environmental Engineering

Iowa State University

2007

Articles 1 - 4 of 4

Full-Text Articles in Engineering

Repetitive Impact Response Of A Beam Structure Subjected To Harmonic Base Excitation, Elizabeth K. Ervin, Jonathan A. Wickert Oct 2007

Repetitive Impact Response Of A Beam Structure Subjected To Harmonic Base Excitation, Elizabeth K. Ervin, Jonathan A. Wickert

Jonathan A. Wickert

This paper investigates the forced response dynamics of a clamped–clamped beam to which a rigid body is attached, and in the presence of periodic or non-periodic impacts between the body and a comparatively compliant base structure. The assembly is subjected to base excitation at specified frequency and acceleration, and the potentially complex responses that occur are examined analytically. The two sets of natural frequencies and vibration modes of the beam-rigid body structure (in its in-contact state, and in its not-in-contact state), are used to treat the forced response problem through a series of algebraic mappings among those states. A modal …


Identification Of Polypeptides Expressed In Response To Vinyl Chloride, Ethene, And Epoxyethane In Nocardioides Sp. Strain Js614 By Using Peptide Mass Fingerprinting, Adina S. Chuang, Timothy E. Mattes Jul 2007

Identification Of Polypeptides Expressed In Response To Vinyl Chloride, Ethene, And Epoxyethane In Nocardioides Sp. Strain Js614 By Using Peptide Mass Fingerprinting, Adina S. Chuang, Timothy E. Mattes

Adina Howe

Enzymes expressed in response to vinyl chloride, ethene, and epoxyethane by Nocardioides sp. strain JS614 were identified by using a peptide mass fingerprinting (PMF) approach. PMF provided insight concerning vinyl chloride biodegradation in strain JS614 and extends the use of matrix-assisted laser desorption-ionization time of flight mass spectrometry as a tool to enhance characterization of biodegradation pathways.


Online Learning Algorithm For Structural Control Using Magnetorheological Actuators, Simon Laflamme Jun 2007

Online Learning Algorithm For Structural Control Using Magnetorheological Actuators, Simon Laflamme

Simon Laflamme

Magnetorheological actuators are promising devices for mitigating vibrations because they only require a fraction of energy for a similar performance to active control. Conversely, these semi-active devices have limited maximum forces and are hard to model due to the rheological properties of their fluid. When considering structural control, classical theories necessitate full knowledge of the structural dynamic states and properties most of which can only be estimated when considering large-scale control, which may be difficult or inaccurate for complicated geometries due to the non-linear behaviour of structures. Additionally, most of these theories do not take into account the response delay …


Artificial Neural Networks For Analyzing Concrete Airfield Pavements Serving The Boeing B-777 Aircraft, Halil Ceylan, Erol Tutumluer, Ernest J. Barenberg Jan 2007

Artificial Neural Networks For Analyzing Concrete Airfield Pavements Serving The Boeing B-777 Aircraft, Halil Ceylan, Erol Tutumluer, Ernest J. Barenberg

Halil Ceylan

An artificial neural network (ANN) model has been trained with the results of the ILLI-SLAB finite element program and has been used to predict stresses and deflections in jointed concrete airfield pavements serving the Boeing B-777 aircraft. The trained ANN model produces stresses and deflections with average errors of less than 0.5 percent of those obtained directly from the finite element analyses. Use of the ANN model has been found to be very effective for correctly predicting ILLI-SLAB stresses and deflections, in less than 1 s, with no requirements of complicated finite element inputs. On the other hand, elastic layered …