Engineering Commons^™

Mechanics Of Pure Bending And Eccentric Buckling In High-Strain Composite Structures, Jimesh D. Bhagatji, Oleksandr G. Kravchenko, Sharanabasaweshwara Asundi

Mechanical & Aerospace Engineering Faculty Publications

To maximize the capabilities of nano- and micro-class satellites, which are limited by their size, weight, and power, advancements in deployable mechanisms with a high deployable surface area to packaging volume ratio are necessary. Without progress in understanding the mechanics of high-strain materials and structures, the development of compact deployable mechanisms for this class of satellites would be difficult. This paper presents fabrication, experimental testing, and progressive failure modeling to study the deformation of an ultra-thin composite beam. The research study examines the deformation modes of a post-deployed boom under repetitive pure bending loads using a four-point bending setup and …

Mechanical Characterizations Of 3d-Printed Plla/Steel Particle Composites, Hozhabr Mozafari, Pengfei Dong, Haitham Hadidi, Michael P. Sealy, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The objective of this study is to characterize the micromechanical properties of poly-L-lactic acid (PLLA) composites reinforced by grade 420 stainless steel (SS) particles with a specific focus on the interphase properties. The specimens were manufactured using 3D printing techniques due to its many benefits, including high accuracy, cost effectiveness and customized geometry. The adopted fused filament fabrication resulted in a thin interphase layer with an average thickness of 3 μm. The mechanical properties of each phase, as well as the interphase, were characterized by nanoindentation tests. The effect of matrix degradation, i.e., imperfect bonding, on the elastic modulus of …

Full Field Computing For Elastic Pulse Dispersion In Inhomogeneous Bars, A. Berezovski, R. Kolman, M. Berezovski, D. Gabriel, V. Adamek

Publications

In the paper, the finite element method and the finite volume method are used in parallel for the simulation of a pulse propagation in periodically layered composites beyond the validity of homogenization methods. The direct numerical integration of a pulse propagation demonstrates dispersion effects and dynamic stress redistribution in physical space on example of a one-dimensional layered bar. Results of numerical simulations are compared with analytical solution constructed specifically for the considered problem. Analytical solution as well as numerical computations show the strong influence of the composition of constituents on the dispersion of a pulse in a heterogeneous bar and …

Migration Resistance Of Esophageal Stents: The Role Of Stent Design, Hozhabr Mozafari, Pengfei Dong, Shijia Zhao, Yonghua Bi, Xinwei Han, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Objective: Stenting is one of the major treatments for malignant esophageal cancer. However, stent migration compromises clinical outcomes. A flared end design of the stent diminishes its migration. The goal of this work is to quantitatively characterize stent migration to develop new strategies for better clinical outcomes.

Methods: An esophageal stent with flared ends and a straight counterpart were virtually deployed in an esophagus with asymmetric stricture using the finite element method. The resulted esophagus shape, wall stress, and migration resistance force of the stent were quantified and compared.

Results: The lumen gain for both the flared stent and the …

The Effect Of Number Of Corrugation On Crashworthiness Of Aluminum Corrugated Tube Under Lateral Loading, Hozhabr Mozafari, Arameh Eyvazian, Abdel Magid Hamouda

Department of Mechanical and Materials Engineering: Faculty Publications

Thin-walled tubes have been developed and are growing in use as new energy absorber structures. The objective of this study is to investigate the energy absorption and crushing characteristics of corrugated tubes with different number of corrugation in a specific length exposed to lateral loading. At the first step, experimental tests were carried out on a corrugated tube with three con'ugations (two inner and one outer) and a tube without corrugation. After that, a finite element model was developed by means of ABAQUS software in order to study the effect of corrugation number on crushing properties of thin-walled tubes. The …

Accommodation Of The Human Lens Capsule Using A Finite Element Model Based On Nonlinear Regionally Anisotropic Biomembranes, G. David, Ryan M. Pedrigi, J. D. Humphrey

Department of Mechanical and Materials Engineering: Faculty Publications

Accommodation of the eyes, the mechanism that allows humans to focus their vision on near objects, naturally diminishes with age via presbyopia. People who have undergone cataract surgery, using current surgical methods and artificial lens implants, are also left without the ability to accommodate. The process of accommodation is generally well known; however the specific mechanical details have not been adequately explained due to difficulties and consequences of performing in vivo studies. Most studies have modeled the mechanics of accommodation under assumptions of a linearly elastic, isotropic, homogenous lens and lens capsule. Recent experimental and numerical studies showed that the …

Finite Element Simulation Of Pzt-Aided Interrogation Of Composite Laminates Exhibiting Damage, Amany Micheal, Yehia Bahei-El-Din

Centre for Advanced Materials

Piezoelectricity has proved effective in capturing changes in structures caused by various damage mechanisms. In one approach, piezoelectric wafer active sensors (PWAS) are mounted on the surface of the host structure and utilized as both actuators and sensors to interrogate the structure and monitor its health. This is achieved by subjecting the PWAS to a transient electric pulse and reading the resulting voltage. Changes in the stiffness of the substrate due to structural damage affect the response of the PWAS, which could be correlated to integrity of the structure. Applying this technique to fibrous composite laminates encounters particular challenges due …

A Multi-Scale Based Model For Composite Materials With Embedded Pzt Filaments For Energy Harvesting, A.E. El-Etriby, M.E. Abdel-Meguid, K.M. Shalan, Tarek Hatem, Yehia Bahei-El-Din

Centre for Advanced Materials

Ambient vibrations are major source of wasted energy, exploiting properly such vibration can be converted to valuable energy and harvested to power up devices, i.e. electronic devices. Accordingly, energy harvesting using smart structures with active piezoelectric ceramics has gained wide interest over the past few years as a method for converting such wasted energy. This paper provides numerical and experimental analysis of piezoelectric fiber based composites for energy harvesting applications proposing a multi-scale modeling approach coupled with experimental verification. The multi-scale approach suggested predicting the behavior of piezoelectric fiber-based composites use micromechanical model based on Transformation Field Analysis (TFA) to …