Engineering Science and Materials Commons^™

Call For Abstracts - Resrb 2019, July 8-9, Wrocław, Poland, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Tailoring Materials Behavior Using Geometry.Pdf, Hessein Ali, Hossein Ebrahimi, Ranajay Ghosh

Hossein Ebrahimi

The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco

Buenaventura "Ven" Basco

No abstract provided.

Multi-Objective Bayesian Optimization Of Super Hydrophobic Coatings On Asphalt Concrete Surfaces, Ali Nahvi, Ali Arabzadeh, Alireza Sassani, Mohammadkazem Sadoughi, Halil Ceylan

Ali Nahvi

Energy Efficient Process Heating: Managing Air Flow, Kevin Carpenter, J. Kelly Kissock

J. Kelly Kissock

Much energy is lost through excess air flow in and out of process heating equipment. Energy saving opportunities from managing air flow include minimizing combustion air, preheating combustion air, minimizing ventilation air, and reconfiguring openings to reduce leakage.

This paper identifies these opportunities and presents methods to quantify potential energy savings from implementing these energy-savings measures. Case study examples are used to demonstrate the methods and the potential energy savings.The method for calculating savings from minimizing combustion air accounts for improvement in efficiency from increased combustion temperature and decreased combustion gas mass flow rate.

The method for calculating savings from …

Umass Amherst Green Building Guidelines 2013, Ludmilla Pavlova-Gillham, Ted Mendoza, Ezra Small, Patricia O'Flaherty, Nariman Mostafavi, Mohamed Farzinmoghadam, Somayeh Tabatabaee Pozveh

Ludmilla D Pavlova

Facilities & Campus Services, Sustainable UMass and Campus Planning support sustainability and energy conservation initiatives by providing in-house resources to campus staff as well as designers and contractors working with the University. The UMass Amherst Green Building Guidelines provide a framework for approaching new construction and major renovation projects at UMass Amherst that are undergoing LEED certification by focusing the conversation on green building aspects that are most important to the campus. They are intended to be the beginning of a dynamic conversation between designers, environmental consultants and constructors, university stakeholders, and users of new high performance buildings.

Analytical And Numerical Analysis Of Low Velocity Impact On Metallic Sandwich Panel With Polyurethane Foam Core, Mohsen Mahdian, Hossein Ebrahimi

Hossein Ebrahimi

No abstract provided.

Resilience-Based Design Of Precast Steel-Concrete Composites For Railway Track Slabs, Sakdirat Kaewunruen, Dane Wp Griffin, Olivia Mirza, Kenny Kwok

Sakdirat Kaewunruen

The relatively high turnover of timber sleepers (crossties in a plain track), bearers (skeleton ties in a turnout), and transoms (bridge cross beams) is responsible for producing greenhouse gas emissions 6 times greater than an equivalent reinforced concrete counterparts. This paper presents an innovative solution for the replacement of aging timber transoms installed on existing railway bridges along with the incorporation of a continuous walkway platform, which is proven to provide environmental, safety and financial benefits. Recent developments for alternative composite materials to replace timber components in railway infrastructure construction and maintenance demonstrate some compatibility issues with track stiffness as …

Optical Detection Of Acoustic Emission Signals, C Harvey Palmer, Robert E. Green Jr

Robert A. Green

Piezoelectric transducers, long used in the generation and detection of ultrasonic waves, have more recently been the detector of choice for acoustic emission signals. Optical probing methods, however, have several important advantages for acoustic emission studies: (1) they have an inherent broad frequency response, free from mechanical resonances, (2) they do not interfere with the acoustic waves. (3) since the focused optical beam diameters are typically only a few hundredths of a millimeter, optical methods can probe very close to a crack or a twin, (4) they can probe internally in transparent media, and (5) they can be used over …

Effects Of Temperature Change On Interfacial Delamination In Thermal Barrier Coatings, Hossein Ebrahimi, Soheil Nakhodchi

Hossein Ebrahimi

No abstract provided.

Zespół Energii Odnawialnej I Zrównoważonego Rozwoju (Eozr), Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Single-Layer Graphene Oxide Reinforced Metal Matrix Composites By Laser Sintering: Microstructure And Mechanical Property Enhancement, Dong Lin

dong lin

No abstract provided.

Optimization Of Contact Pattern Position On The Worm Wheel Teeth By Axial Shift In Worm Wheel Axis, Ehsan Soury, Arash Houshmand, Alireza Nezamabadi

Arash Houshmand

In industrial applications Lubricant temperature decrease is a desired aim in the case of lubricant and gears performance. In this paper the procedure of optimization of worm gears performance by considering the proper contact pattern position had been performed. In accordance with required axial shift in worm wheel axis the contact pattern optimized and as a result the lubricant temperature decreased. This procedure leads to increase gears efficiency and their effective life.

Morphological Instability Leading To Formation Of Porous Anodic Oxides, Ömer Çapraz, Kurt Hebert, Pranav Shrotriya

Ömer Özgür Çapraz

No abstract provided.

Impact Damage On A Thin Glass Plate With A Thin Polycarbonate Backing, Wenke Hu, Yenan Wang, Jian Yu, Chian-Fong Yen, Florin Bobaru

Florin Bobaru Ph.D.

We present experimental and computational results for the impact of a spherical projectile on a thin glass plate with a thin polycarbonate backing plate, restrained in a metal frame, or in the absence of the frame. We analyze the dependence of the damage patterns in the glass plate on the increasing impact velocities, from 61 m/s to 200 m/s. Experimental results are compared with those from peridynamic simulations of a simplified model. The main fracture patterns observed experimentally are captured by the peridynamic model for each of the three projectile velocities tested. More accurate implementation of the actual boundary conditions …

Finite Element Analysis Of The Ramberg-Osgood Bar, Dongming Wei

Dongming Wei

In this work, we present a priori error estimates of finite element approximations of the solution for the equilibrium equation of an axially loaded Ramberg-Osgood bar. The existence and uniqueness of the solution to the associated nonlinear two point boundary value problem is established and used as a foundation for the finite element analysis.

Development Of A Novel Handheld Device For Active Compensation Of Physiological Tremor, Abhijit Saxena

Abhijit Saxena

In microsurgery, the human hand imposes certain limitations in accurately positioning the tip of a device such as scalpel. Any errors in the motion of the hand make microsurgical procedures difficult and involuntary motions such as hand tremors can make some procedures significantly difficult to perform. This is particularly true in the case of vitreoretinal microsurgery. The most familiar source of involuntary motion is physiological tremor. Real-time compensation of tremor is, therefore, necessary to assist surgeons to precisely position and manipulate the tool-tip to accurately perform a microsurgery. In this thesis, a novel handheld device (AID) is described for compensation …

The Formulation And Computation Of The Nonlocal J-Integral In Bond-Based Peridynamics, Wenke Hu, Youn Doh Ha, Florin Bobaru, Stewart A. Silling

Florin Bobaru Ph.D.

This work presents a rigorous derivation for the formulation of the J-integral in bond-based peridynamics using the crack infinitesimal virtual extension approach. We give a detailed description of an algorithm for computing this nonlocal version of the J-integral.We present convergence studies (m-convergence and δ-convergence) for two different geometries: a single edge-notch configuration and a double edge-notch sample.We compare the results with results based on the classical J-integral and obtained from FEM calculations that employ special elements near the crack tip.We identify the size of the nonlocal region for which the peridynamic J-integral value is near the classical FEM solutions.We discuss …

The Meaning, Selection, And Use Of The Peridynamic Horizon And Its Relation To Crack Branching In Brittle Materials, Florin Bobaru, Wenke Hu

Florin Bobaru Ph.D.

This note discusses the peridynamic horizon (the nonlocal region around a material point), its role, and practical use in modeling. The objective is to eliminate some misunderstandings and misconceptions regarding the peridynamic horizon. An example of crack branching in a nominally brittle material (homalite) is addressed and we show that crack branching takes place without wave interaction. We explain under what conditions the crack propagation speed depends on the horizon size and the role of incident stress waves on this speed.

Convergence, Adaptive Refinement, And Scaling In 1d Peridynamics, Florin Bobaru Ph.D., Mijia Yabg Ph.D., Leonardo F. Alves M.S., Stewart A. Silling Ph.D., Ebrahim Askari Ph.D., Jifeng Xu Ph.D.

Florin Bobaru Ph.D.

We introduce here adaptive refinement algorithms for the non-local method peridynamics, which was proposed (in J. Mech. Phys. Solids 2000; 48:175–209) as a reformulation of classical elasticity for discontinuities and long-range forces. We use scaling of the micromodulus and horizon and discuss the particular features of adaptivity in peridynamics for which multiscale modeling and grid refinement are closely connected. We discuss three types of numerical convergence for peridynamics and obtain uniform convergence to the classical solutions of static and dynamic elasticity problems in 1D in the limit of the horizon going to zero. Continuous micromoduli lead to optimal rates of …

Influence Of Van Der Waals Forces On Increasing The Strength And Toughness In Dynamic Fracture Of Nanofibre Networks: A Peridynamic Approach, Florin Bobaru Ph.D.

Florin Bobaru Ph.D.

The peridynamic method is used here to analyse the effect of van der Waals forces on the mechanical behaviour and strength and toughness properties of three-dimensional nanofibre networks under imposed stretch deformation. The peridynamic formulation allows for a natural inclusion of long-range forces (such as van der Waals forces) by considering all interactions as ‘long-range’. We use van der Waals interactions only between different fibres and do not need to model individual atoms. Fracture is introduced at the microstructural (peridynamic bond) level for the microelastic type bonds, while van der Waals bonds can reform at any time. We conduct statistical …

Crack Nucleation In A Peridynamic Solid, S. Silling, O. Weckner, E. Askari, Florin Bobaru

Florin Bobaru Ph.D.

A condition for the emergence of a discontinuity in an elastic peridynamic body is proposed, resulting in a material stability condition for crack nucleation. The condition is derived by determining whether a small discontinuity in displacement, superposed on a possibly large deformation, grows over time. Stability is shown to be determined by the sign of the eigenvalues of a tensor field that depends only on the linearized material properties. This condition for nucleation of a discontinuity in displacement can be interpreted in terms of the dynamic stability of plane waves with very short wavelength. A numerical example illustrates that cracks …

Studies Of Dynamic Crack Propagation And Crack Branching With Peridynamics, Youn Doh Ha Ph.D., Florin Bobaru Ph.D.

Florin Bobaru Ph.D.

In this paper we discuss the peridynamic analysis of dynamic crack branching in brittle materials and show results of convergence studies under uniform grid refinement (m-convergence) and under decreasing the peridynamic horizon (δ-convergence). Comparisons with experimentally obtained values are made for the crack-tip propagation speed with three different peridynamic horizons.We also analyze the influence of the particular shape of themicro-modulus function and of different materials (Duran 50 glass and soda-lime glass) on the crack propagation behavior. We show that the peridynamic solution for this problem captures all the main features, observed experimentally, of dynamic crack propagation and branching, as well …

Green Scheduling For Radiant Systems In Buildings, Truong X. Nghiem, Madhur Behl, George J. Pappas, Rahul Mangharam

Truong X Nghiem

In this report we look at the problem of peak power reduction for buildings with electric radiant floor heating systems. Uncoordinated operation of a multi-zone radiant floor heating system can result in temporally correlated electricity demand surges or peaks in the building’s electricity consumption. As peak power prices are 200-400 times that of the nominal rate, this uncoordinated activity can result in high electricity costs and expensive system operation. We have previously presented green scheduling as an approach for reducing the aggregate peak power consumption in buildings while ensuring that indoor thermal comfort is always maintained. This report extends the …

Determination Of Kinetic Parameters From The Thermogravimetric Data Set Of Biomass Samples, Karol Postawa, Wojciech M. Budzianowski

Wojciech Budzianowski

This article describes methods of the determination of kinetic parameters from the thermogravimetric data set of biomass samples. It presents the methodology of the research, description of the needed equipment, and the method of analysis of thermogravimetric data. It describes both methodology of obtaining quantitative data such as kinetic parameters as well as of obtaining qualitative data like the composition of biomass. The study is focused mainly on plant biomass because it is easy in harvesting and preparation. Methodology is shown on the sample containing corn stover which is subsequently pyrolysed. The investigated sample show the kinetic of first order …

Green Scheduling For Radiant Systems In Buildings, Truong X. Nghiem, Madhur Behl, George J. Pappas, Rahul Mangharam

Madhur Behl

In this report we look at the problem of peak power reduction for buildings with electric radiant floor heating systems. Uncoordinated operation of a multi-zone radiant floor heating system can result in temporally correlated electricity demand surges or peaks in the building’s electricity consumption. As peak power prices are 200-400 times that of the nominal rate, this uncoordinated activity can result in high electricity costs and expensive system operation. We have previously presented green scheduling as an approach for reducing the aggregate peak power consumption in buildings while ensuring that indoor thermal comfort is always maintained. This report extends the …

Green Scheduling For Radiant Systems In Buildings, Truong Nghiem, Madhur Behl, George Pappas, Rahul Mangharam

Rahul Mangharam

In this report we look at the problem of peak power reduction for buildings with electric radiant floor heating systems. Uncoordinated operation of a multi-zone radiant floor heating system can result in temporally correlated electricity demand surges or peaks in the building’s electricity consumption. As peak power prices are 200-400 times that of the nominal rate, this uncoordinated activity can result in high electricity costs and expensive system operation. We have previously presented green scheduling as an approach for reducing the aggregate peak power consumption in buildings while ensuring that indoor thermal comfort is always maintained. This report extends the …

Investigation Of Thermomechanical Effects Of Lighting Conditions On Canvas Paintings By Laser Shearography, Morteza Khaleghi, Ivo Dobrev, Philip Klausmeyer, Ellery Harrington, Cosme Furlong

Morteza Khaleghi

Quantitative techniques to characterize thermomechanical effects of light on canvas paintings are necessary in order to better understand the deleterious effects that light has on precious art collections in museum exhibitions. In this paper, we present advances in the development of a customized laser shearography system for temporal characterization of in-plane displacements of canvas paintings when subjected to specific lighting conditions. The shearography system is synchronized with a thermal IR camera and concomitant measurements of derivatives of displacements along two orthogonal shearing directions as well as thermal fields are performed. Due to the nature of the measurements, we have developed …

Hydrogen Production From Biogas By Oxy-Reforming: Reaction System Analysis, Aleksandra Terlecka, Wojciech M. Budzianowski

Wojciech Budzianowski

Oxy-reforming is emerging as an interesting alternative to conventional methods of hydrogen generation. The current article characterises this process through analysis of individual reactions: SMR (steam methane reforming), WGS (water gas shift) and CPO (catalytic partial oxidation). Analyses relate to optimisation of thermal conditions thus enabling cost-effectivenes of the process.

Reverse Logic - Safety Of Spent Nuclear Fuel Disposal, Antti Lempinen, Marianne Silvan-Lempinen

Antti Lempinen

No abstract provided.