Roth J.T.,Penn State Erie |
Djurdjanovic D.,University of Texas at Austin |
Yang X.,Cummins Inc. |
Mears L.,Clemson University |
Kurfess T.,Clemson University
Journal of Manufacturing Science and Engineering, Transactions of the ASME | Year: 2010
Tool condition monitoring (TCM) is an important aspect of condition based maintenance (CBM) in all manufacturing processes. Recent work on TCM has generated significant successes for a variety of cutting operations. In particular, lower cost and on-board sensors in conjunction with enhanced signal processing capabilities and improved networking has permitted significant enhancements to TCM capabilities. This paper presents an overview of TCM for drilling, turning, milling, and grinding. The focus of this paper is on the hardware and algorithms that have demonstrated success in TCM for these processes. While a variety of initial successes are reported, significantly more research is possible to extend the capabilities of TCM for the reported cutting processes as well as for many other manufacturing processes. Furthermore, no single unifying approach has been identified for TCM. Such an approach will enable the rapid expansion of TCM into other processes and a tighter integration of TCM into CBM for a wide variety of manufacturing processes and production systems. Copyright © 2010 by ASME.
Nazzal M.,German Jordanian University |
Abu-Farha F.,Penn State Erie |
Curtis R.,King's College London
Journal of Materials Engineering and Performance | Year: 2011
Characterizing the behavior of superplastic materials is largely based on the uniaxial tensile test; yet the unique nature of these materials requires a particularly tailored testing methodology, different to that used with conventional materials. One of the crucial testing facets is the specimen geometry, which has a great impact on the outcome of a superplastic tensile test, as a result of the associated extreme conditions. And while researchers agree that it should take a notably different form than the typical dog-bone shape; there is no universal agreement on the specimen's particular size and dimensions,as evident by the disparities in test specimens used in the various superplastic testing efforts found throughout the literature. In view of that, this article is dedicated to understanding the effects of specimen geometry on the superplastic behavior of the materialduring tensile testing. Deformation of the Ti6Al4V titanium alloy is FE simulated based on a multitude of specimen geometries, covering a wide range of gauge length, gauge width,grip length, and grip width values. The study provides key insights on the influences of each geometrical parameter as well as their interactions, and provides recommendations onselecting the specimen's proportions for accurate and unified tensile testing of superplastic materials.
Schnars J.L.,Tom Ridge Environmental Center |
Voss M.A.,Penn State Erie |
Stauffer J.R.,Pennsylvania State University
Environmental Toxicology and Chemistry | Year: 2011
Embryos of oviparous organisms are exposed to contaminants by two pathways: contaminant uptake from the surrounding environment, and the transfer from female to offspring (maternal transfer). The initial source of contaminant exposure for most embryos is likely to be maternal transfer; therefore, maternal transfer studies are critical in determining the effects of contaminants on future populations. Injection of contaminants directly into eggs is one route of experimental contaminant exposure that permits controlled doses and potential reliable replication. This technique, however, has been used in the past with little success in reptiles. The objective of the present study was to evaluate egg injection as a means of mimicking maternal transfer of polychlorinated biphenyls (PCBs) to snapping turtle eggs. Eggs from several clutches were injected with a PCB solution and incubated at several temperatures and moisture levels to measure interactive effects of injection, environmental condition, and contaminant load on hatching success. The injection technique allowed for application of consistent and specific doses among replicates. Overall hatching success in this study was 61% and was as high as 71% within specific treatments. Hatching success was much higher in this study than in other studies using egg injections to mimic maternal transfer in chelonians and crocodilians. © 2010 SETAC © 2010 SETAC.
Andreopoulos Y.,City College of New York |
Danesh-Yazdi A.H.,Penn State Erie |
Goushcha O.,City College of New York |
Elvin N.,City College of New York
ASME 2015 Dynamic Systems and Control Conference, DSCC 2015 | Year: 2015
Turbulent flows carry mechanical energy distributed over a range of temporal and spatial scales and their interaction with a thin immersed piezoelectric beam results in a strain field which generates electrical charge. This energy harvesting method can be used for developing self-powered electronic devices such as flow sensors. In the present experimental work, various energy harvesters were placed in a turbulent boundary layer or inside a decaying flow field of homogeneous and isotropic turbulence. The role of large instantaneous turbulent structures in this rather complex fluid-structure interaction is discussed in interpreting the electrical output results. The forces acting on the vibrating beams have been measured dynamically and a theory has been developed which incorporates the effects of mean local velocity, turbulence intensity, the relative size of the beam's length to the integral length scale of turbulence, the structural properties of the beam and the electrical properties of the active piezoelectric layer to provide reasonable estimates of the mean electrical power output. Experiments have been carried out in which these fluidic harvesters are immersed first in inhomogeneous turbulence like that encountered in boundary layers developing over solid walls and homogeneous and isotopic turbulence for which a simplified analytical description exists. It was found that there is a non-linear effect of turbulence length scales on the power output of the fluidic harvesters. © Copyright 2015 by ASME.
Abu-Farha F.,Penn State Erie |
Hector Jr. L.G.,General Motors
Journal of Manufacturing Science and Engineering, Transactions of the ASME | Year: 2011
The formability curves of AZ31B magnesium and 5083 aluminum alloy sheets were constructed using the pneumatic stretching test at two different sets of forming conditions. The test best resembles the conditions encountered in actual hydro/pneumatic forming operations, such as the superplastic forming (SPF) and quick plastic forming (QPF) techniques. Sheet samples were deformed at (400 °C and 1×10-3 s-1) and (450 °C and 5×10-3 s-1), by free pneumatic bulging into a set of progressive elliptical die inserts. The material in each of the formed domes was forced to undergo biaxial stretching at a specific strain ratio, which is simply controlled by the geometry (aspect ratio) of the selected die insert. Material deformation was quantified using circle grid analysis (CGA), and the recorded planar strains were used to construct the forming limit curves of the two alloys. The aforementioned was carried out with the sheet oriented either along or across the direction of major strains in order to establish the relationship between the material's rolling direction and the corresponding limiting strains. Great disparities in limiting strains were found in the two orientations for both alloys; hence, a "composite FLD" is introduced as an improved means for characterizing material formability limits. © 2011 by ASME.
Abu-Farha F.,Penn State Erie |
Hector L.,General Motors |
Krajewski P.,General Motors
SAE 2011 World Congress and Exhibition | Year: 2011
Forming Limit Curves (FLCs) were developed for the 5083 aluminum alloy at conditions simulating high temperature processes such as superplastic and quick plastic forming. Sheet samples were formed at 450 °C and at a constant strain rate of 5ã - 10-3 s-1, by free bulging into a set of elliptical die inserts with different aspect ratios. Friction-independent formability diagrams, which distinguish between the safe and unsafe deformation zones, were constructed. Although the formability diagrams were confined to the biaxial strain region (right side quadrant of an FLD), the elliptical die insert methodology provides formability maps under conditions where traditional mechanical stretching techniques are limited. © 2011 SAE International.
Weissbach R.S.,Penn State Erie |
King J.R.,Penn State Erie
IEEE Green Technologies Conference | Year: 2013
The use of energy storage in conjunction with renewable energy sources such as wind and solar is receiving more attention to help mitigate the effects of the intermittent nature of these sources at off-grid residences. One wishes to maximize the probability that there will be enough energy available to meet the residential load demand while minimizing the cost of both the renewable energy sources as well as the energy storage device(s). In this paper, the energy storage required to ensure high reliability of supply to an off-grid residence in the Midwest is determined iteratively based on the amount of installed solar power. A Markov model is employed consisting of 288 state transition matrices to generate synthetic solar data for analysis. By accounting for the costs of both the photovoltaic system and the energy required energy storage, an optimal cost solution is provided. © 2013 IEEE.
Carson S.,Penn State Erie |
Schmader J.,Penn State Erie |
Smith G.,Penn State Erie
Annual Technical Conference - ANTEC, Conference Proceedings | Year: 2011
The effects on mechanical properties of blending different levels by weight of talc, silica, and glass fibers in Liquid Silicone Rubber systems was investigated. Specifically, tensile strength, hardness, elongation, and compression set behavior was measured for unblended resin and each level of additive. A material property characterization was developed from these measurements. It was determined that talc and silica had better dispersion and both modifying and reinforcing effects, while the glass had none.
Sweeney S.K.,Penn State Erie
SAE International Journal of Commercial Vehicles | Year: 2011
Several recent product developments for vibration and motion control have needed passive viscous damping, in addition to traditional elastomer-based hysteretic damping, to be successful in their respective applications. In addition to attenuating steady-state vibration, an important function of these recent product developments is to control motion from impulsive or mechanical shock input. Examples are the cab mounts of off-highway vehicles that need damping in the vertical direction to control cab motion from ground input through the vehicle and some torsionally flexible couplings that need damping to control torque spikes from shift shocks or other transient events. In this work, the theoretical damped impulse response quantities of displacement, velocity, acceleration, force, jerk, yank, and jounce are investigated. This work shows that, for certain response quantities, there is a specific magnitude of damping that minimizes response from impulsive or mechanical shock input. Further, this work shows that the specific magnitude of damping to minimize response depends upon the quantity considered. This work also shows that the magnitudes of damping needed to minimize response from impulsive or mechanical shock input are higher than what is readily attainable with the hysteretic damping of elastomeric products, substantiating the need to add passive viscous damping in recent elastomeric product developments. © 2011 SAE International.
Sweeney S.K.,Penn State Erie
SAE Technical Papers | Year: 2011
This work provides a theoretical analysis of the natural and forced lateral vibration in a driveline having a flexible coupling and universal joints. The analysis is specific to the front driveline common in many off-highway vehicles which usually consists of a flexible coupling at the engine flywheel, the driveshaft, and one or two universal joints. A torsionally flexible coupling is often needed in a front driveline to suppress torsional vibration. The problem is that most torsionally flexible couplings are also inherently flexible in their radial and cocking directions. These additional directions of flexibility, compounded by the presence of universal joints, can result in unexpectedly low lateral natural frequencies of the driveline. With a few axial dimensions, mass properties of the driveline, and stiffness properties of the flexible coupling, this work provides simple, closed-form calculations for the lowest lateral natural frequencies. This work also investigates the lateral disturbances to the driveline that can result in synchronous whirl. Copyright © 2011 SAE International.