CAV Review ‘11

CAV Review ‘11-’12Welcome New CAV MembersNew Distance Education DirectorThe CAV has experienced growth in the membership of faculty and research staff this past year. Those who have joined us bring experience intheir respective fields, fresh ideas and possible avenues for research collaboration. We welcome the following new members.Russell Joins Acoustics ProgramDr. Cliff Lissenden is a professor of engineeringscience and mechanics, having joined The Pennsylvania State University in August 1995 as an assistant professor. His ongoing research is in the areaof structural health monitoring and nondestructiveevaluation using ultrasonic guided waves. Phasedarray transducers are being designed to providemode control and steer an ultrasonic beam that issensitive to degradation of joints on compositestructures. Piezoelectric strip transducers are beinginvestigated to monitor hot spots in plate and shellstructures. Tomographic imaging algorithms arebeing developed to visualize fatigue crack growthin multilayer metal structures. Nonlinear ultrasonic guided waves arebeing researched in order to characterize the evolution of microstructuredue to thermal aging, creep, and plasticity through the generation of higher harmonics.The Graduate Program in Acoustics is pleasedto announce that Dr. Daniel A. Russell (formerlyof Kettering University/GMI Engineering &Management Institute) has joined Penn State asProfessor of Acoustics and Director of DistanceEducation. Dr. Russell is widely known for hisacoustics animations website and for his research involving the acoustics and vibration ofsports equipment and musical instruments. For16 years while at Kettering University, Dr. Russell worked with many co-op students workingin the automotive and manufacturing industries.In addition to teaching several of our acoustics courses, Dr. Russell oversees, manages, and markets the distance education component of PennState’ Acoustics program. For example, in Spring 2012 Dr. Russell taughtACS 537 Noise Control Engineering to a record enrollment, in a blendedenvironment, to both in-resident and distance education students. Tocontact Dr. Russell please email drussell@engr.psu.edu. Please join us inwelcoming him to Penn SateCAV Anechoic Room RecharacterizedDr. Daniel G. Linzell, P.E. is the John A. andHarriette K. Shaw Professor of Civil Engineering and Director of the Protective TechnologyCenter at The Pennsylvania State University.He received his Ph.D. in Civil Engineering fromthe Georgia Institute of Technology in 1999, hisM.S. in Civil Engineering from Georgia Tech in1995 and a B.S. in Civil Engineering from theOhio State University in 1990. He served as avisiting professor at TECNUN, the engineeringcampus of the University of Navarra in SanSebastian, Spain, during the 2008-09 academicyear. Dr. Linzell has published over 40 refereedarticles in areas related to structural engineering that have included research related to: protective barrier systems;building and bridge systems and components under blast and impactloads; the behavior of bridges during construction and under serviceloads; and ship structural components under static and dynamic loads.structural inspections on bridges, buildings and other infrastructure systems.CAV Members Organize ConferenceSteve Hambric, General Chair and Steve Conlon, Technical Chair, areorganizing this year’s Internoise conference, to be held 19-22 August inNew York City.Internoise is sponsored by the International Institute ofNoise Control Engineering (I-INCE)and the USAbranch—INCE-USA.Over 1,000 paperswill be presented atthe conference, withover 65 vendorsdisplaying hardware, software, and noise and vibration control solutions. To learn moreabout the conference and to register see www.internoise2012.com.Paul Bauch, M.S. student in our Acoustics program, has recharacterizedour CAV hemi-anechoic room. Combined with Andrew Orr’s (M.S.Acoustics, 2011) recharacterization of the CAV reverberant room, Paul ispreparing to update and benchmark sound tramsmission loss procedures through our window between the two roms.3

CAV Review ‘11-’12T ec hn i ca l Re sear ch G rou p Hig h l ig htsAcoustics Characterization of MaterialsControl Technical Group is to pursue strategiesfor reducing vibration and noise in engineeringsystems. This involves the development of activematerials and devices, accurate modeling apThe mission of the Acoustics Characterization of proaches, passive control methods, discrete anddistributed sensors and actuators as well asMaterials group is to develop a new underplacement strategies, structural integrationstanding of how various types of waves, i.e.,ultrasonic x-ray, thermal, optical, electromagnet- methods, fast and stable adaptive control algorithms, and experiments to evaluate real-worldic, acoustic, etc., interact with advanced materiperformance. In complex mechanical/acousticalals; to translate this understanding into techniques for monitoring and controlling industrial systems with multiple sensing and source/actuator locations, significant challenges remain.processes; and to apply these techniques to thedevelopment of materials processes.Professor George Lesieutre and his students arepursuing a number of projects in vibration conRecent graduate students—trol and active structures. Working with Prof.Manton Guers received his Ph.D. in AugustFrecker's group, and with the support of the2011. he is to be employed at the Applied ReNational Science Foundation, they are pursuingsearch Laboratory. He can be reached atthe development of high-strain-capable ceramicmjg244@psu.edu.materials. The National Rotorcraft TechnologyCenter (NRTC) supports a project that involvesSahar Masghsoudy-Louyeh graduated in Maythe active deployment of small trailing-edge2011 and is now at Airspace Cor., Los Angeles,devices to improve rotor performance. The LordCA.Corporation sponsors a program to improve theCliff Searfass received is Ph.D. this May and will dynamic behavior of helicopter lag dampers.Finally, NASA supports a research effort thatshortly be working at Hitachi Research Laboraaims to damp vibrations of integrally-bladedtory, Tokyo, Japan.turbomachinery rotors using piezoelectric materials.David Parks received his Ph.D. and is now atBernhard R. Tittmann, Group Leaderbrt14@psu.eduIdaho National Laboratory, Idaho Springs, Idaho.Shawn Getty has earned his M.S. and will beworking at General Motors Co. Chicago, Michigan.Ongoing work—Xiaoning Xi is continuing her work on her Ph.D.research and thesis.Brian Reinhardt is continuing his work on hisPh.D.New graduate students to our group are—Robert Cyphers—M.S. candidate.Jeoung Kim (Acoustics) - M.S. candidate.Current Undergraduate Students —Christiane PheilKyle SindingVisiting Scholar—Taesung Park is a Ph.D. candidate from theKorean Institute of Technology and will be atPenn State for 6 months. His research is in“Nondestructive Evaluation of Thin Films byOptical and Acoustic Microscopy.”Active Structures and Noise ControlGeorge Lesieutre, group leadergal4@psu.eduThe mission of the Active Structures and NoiseControl Technical Group is to pursue strategiesTitle: High-Strength High-Strain Structures Using Ceramic Cellular Contact-Aided CompliantMechanisms (C3M)Sponsor: NSFSummary: Cellular Contact-Aided CompliantMechanisms (C3M) are cellular structures withintegrated contact mechanisms that providestress relief. C3M are capable of large strainscompared to their bulk material constituentsand, due to the stress relief, are capable of evengreater strains than their non-contact cellularcounterparts. Originally developed by Drs.Frecker and Lesieutre for the skin of morphingaircraft vehicles, C3M have the potential to beused in many applications requiring large strain.In this project we are developing integrateddesign and fabrication methods for highstrength high-strain ceramic C3M. Ceramic materials are of interest because of their highstrength particularly at the mesoscale, with over2 GPa bend strength, and potential high temperature capability. Bulk ceramic materials alsohave high strength, but low strain at failure,perhaps 0.2 – 1.0 percent, depending on the size.In contrast, ceramic C3M are capable of ultimatestrains of 11 to 13 percent, an order of magnitudehigher than the ultimate strain of the bulk material. This project brings together expertise inmaterials, fabrication, modeling, and design.Collaborators: Dr. Mary Frecker (ME), Dr. JimTitle: Multi-State Lag DampersAdair (MatSci)Sponsor: Lord CorporationStudent: Jennifer Hyland, M.S. expected August,Summary: A multi-state lead-lag damper is de- 2012signed to reduce damper forces when dampingis not required. This isTitle: Reduction of High-Cycle Fatigue in Inteachieved via a set of bypassgrally Bladed Rotors through Piezoelectric Vichannels than can bebration Damping and Controlopened or closed in order toSponsor: NASA Glenn Research Centervary the damper forces. ASummary: A robust vibration damping systemfirst generation prototypefor integrally bladed rotors can dramaticallywas built and bench testedreduce high-cycle fatigue in turbomachinery.to validate the multi-stateSuch a system can be implemented using piezoebehavior. Additionally, to predict the damper lectric materials in both passive and active roles.behavior, an analytical model and a computa- Current research focuses on semi-active resotional fluid dynamics (CFD) model using the nance de-tuning, and modeling using an ascommercial program FLUENT were developed. sumed-modes method. The approach involvesThe prototype damper was bench tested over a detuning the structural resonance frequencyrange of frequencies and dynamic displacements from a (changing) excitation frequency by alterin both the open and closed configurations. ing the structural stiffness (by switching theComparison between the open and closed con- electrical boundary conditions of a piezoelectricfigurations demonstrated the ability of the by- element), thus limiting the structural dynamicpass channels to reduce damper force by more response. Including a switch back to the originalthan 70%, with the capability to tune this value stiffness state, detuning requires two switchesby varying the bypass channel diameter. The per resonance / excitation frequency crossing,CFD model allows detailed investigation into the orders of magnitude fewer than other stateinternal flow dynamics of the damper device switching approaches that require four switchesand is able to capture the general shape of the per cycle of vibration. The detuning methodexperimental force vs. displacement hysteresis provides the greatest normalized vibration reloops. Rotor tests confirmed the validity of the duction for slow sweeps, low damping, and highbypass damper concept.coupling coefficient.Collaborator: Dr. Edward Smith (Aerospace)Student: Jeff Kauffman, Ph.D. expected August,Student: Conor Marr, Ph.D. expected May 2012 20124

CAV Review ‘11-’12T ec hn i ca l Gr oup R es ear ch Hig h l ig htsTitle: Radial Bearing Isolator for HelicopterNoise ReductionSponsor: FellowshipSummary: Main transmission bearings are ofcritical importance to flight safety, noise, andmaintainability/reliability. Reduced cabin noiseis becomingmore criticalashearinglossissuesdevelop forDoD passengers. A majorsourceofnoise is gearmeshing vibration that is transmitted to the cabin via hard mounts, bearings, and the housing.Considerable research has addressed interiornoise reduction strategies. In general, these involve modification of the vibration and acoustictransmission paths from the gearbox to the cabin. Examples include the use of mounts to isolatethe gearbox from the fuselage, and tailored fuselage panels. Passive approaches are preferred,but are not always capable of meeting demanding requirements. This research is pursuing amultilayered metal-elastimer bearing isolatorthat will reduce the vibration transmitted fromthe gearbox to the transmission housing andnoise to the cabin.Collaborator: Dr. Edward Smith (Aerospace)Student: Pauline Autran, M.S. expected August,2012Title: Controllable Lag Damping via DeployableDrag DevicesSponsor: FellowshipSummary: Traditional root-end lag dampers arerequired to prevent ground- and air-resonanceinstabilities in rotorcraft, and thus find widespread use. Although these instabilities are of concern under limitedoperational conditions, the dampersare always active,leading to persistent loading of the damper and rotor. Significantbenefits would ensue from the ability to deploydamping only when it is needed. One conceptfor variable lag damping is a deployable dragbrake. Such a device, located on the outer span,towards or at the tip, would be deployed onlywhen the blade is oscillating at its lag naturalfrequency, and actuation without power externalto the rotor is a key goal. This damping conceptrequires some method to sense blade lag motion,and means for accomplishing this are also beinginvestigated.Collaborator: Dr. Edward Smith (Aerospace)Student: Anna Winslow, M.S. expected December 2012Title: Variable Thermal Conductivity Structures for Spacecraft Thermal Control usingCeramic-Metal Cellular Contact‐aided Compliant MechanismsSponsor: AFOSRSummary: C3M are cellular structures withnovel integrated contact mechanisms that provide local stress relief under high loads; whenactive, these contact mechanisms also introducenew thermal conduction pathways. C3M arecapable of sustaining very large effective strainscompared to those of their bulk material constituents, and are capable of greater strains thantheir non-contact cellular counterparts. We areexploring the potential benefits of C3M in applications requiring high thermal performancealong with structural functionality, with emphasis on spacecraft thermal control. The research effort spans synthesis and fabricationover multiple length scales, and brings togethera unique interdisciplinary team to pursue enhanced thermomechanical performance instructural applications relevant to Air Forceneeds.Collaborators: Dr. Mary Frecker (ME), Dr. JimAdair (MatSci)Student: Rebecca Stavely, M.S. expected August 2013choice of a large N may result in a high ordercompensator that is difficult to implement.Using Lyapunov-based approaches that do notrequire discretization, we design controllers thatasymptotically stabilize the distributed model.This mathematically elegant method eliminatesthe spillover instabilities associated with traditional control approaches, produces simple, loworder, physically intuitive controllers, and is applicable to nonlinear systems. The approach applies mathematical tools based on functional analysis, semigroup theory, and Lyapunov’s DirectMethod to a specific mechatronic system. In addition, Lyapunov-based techniques such asadaptive andbacksteppingcontrol can beused to account for parametric uncertainty and electrical dynamics, respectively. Unlike most researchers in this areawho focus exclusively on mathematics, we experimentally implement the proposed controllers anddemonstrate the improved performance providedby the control. This often requires the development of novel mechatronic sensing and actuationMECHATRONICS RESEARCH LABschemes to measure the required feedback variaC. Rahn - Directorbles and apply the required system inputs. Thefigure shows, for example, a distributed parameThe Mechatronics Research Lab specializes in a ter model-based control experiment for repetitivemulti-physics model-based approach to control learning force tracking in a whisker sensor for theand design of mechatronic systems. The reNavy.search has been supported by funding fromNSF, NIH, AFOSR, ONR, Army, DOE, DOC,NSF is currently supporting an EFRI project inand industry. Research in the MRL is currently smart structures with Prof. Kon-Well Wang andconcentrated in three areas: Smart structures,two other PIs from Michigan and Prof. Chuckbattery systems engineering, and advancedBakis here at Penn State. The overall goal of thisactuators.research is tocreate a transFluidSmart Structures. Our focus has been on theformativemodel-based control of distributed parametermultifuncsystems. Distributed parameter models accutional adaprately represent the physics of many electrome- tive structurechanical systems. These models typically con- conceptsist of partial differential equations (PDEs) forthrough inthe distributed mechanical subsystem, bounda- vestigatingry conditions, electromechanical coupling equa- the uniquetions, and ordinary differential equationsand desirable characteristics of plants; including(ODEs) for the electrical subsystem. Applicanastic (rapid plant motions) actuation with largetions include flexible cable cranes, high-speedforce and stroke and self-sensing/machining spindles, active noise control sysreconfiguration/healing. More specifically, wetems, flexible robot arms, marine cable systems, propose to develop and investigate new bioand high-speed web and fiber handling sysactuation/bio-sensing ideas building upon innotems. Traditionally, the distributed equationsvations inspired by the mechanical, chemical, andare discretized to a finite number (N) of lowelectrical properties of plant cells. We have alorder modes, resulting in a set of ODEs that can ready demonstrated the vibration isolation charbe used for control design using standard tools. acteristics of a fluidlastic cell coupled to a mass.For systems with low damping, however,The figure shows the theoretically predicted andchoosing N too small can cause spillover insta- experimentally demonstrated transmission isolabilities in the high order modes. Alternatively, tion zero at around 28 Hz. One of our challenges5

CAV Review ‘11-’12T ec hn i ca l Gr oup R es ear ch Hig h l ig htsin this project is to extend the initial success in a ium ion concentration on the active particle surdiscretized structure to a distributed, hypercel- faces (b) and in the electrolyte (c). These reducedorder models can then be used as the basis forlular structure.Kalman filters and parameter estimators thatAdvanced Actuators. Working with colleagues predict real-time state of charge, internal batteryconditions, and state of health. Dynamic currentin the Electrical Engineering department, welimits, based on minimizing the predominantare helping to develop small and lightweightactuators for vehicles and medical applications. damage mechanism, enable long lived energystorage systems.AFOSR is currently supporting a project todevelop piezoeStudents and Graduation Dateslectric (PZT) actuBin Zhu (PhD), Spring 2014ators and wingsChris Ferone (MS), Spring 2013for Nano AirGithin Prasad (PhD), Spring 2013Vehicles (NAVs).Kiron Mateti (PhD), Summer 2011Prof. SrinivasLloyd Scarborough (PhD), Winter 2012Tadigadapa andMICHAEL ROBINSON (MS), Spring 2012MRL team memNicolas Kurczewski (PhD), Spring 2015bers invented the T-beam actuators that proRory Byrne-Dugan (MS), Spring 2012vide two-axis displacement from bulk PZTstructure. These actuators have been integrated Varma Gottimukkala (MS), Spring 2011Ying Shi (PhD), Spring 2013with polymer flexures to produce the clappingZheng

ing social at the Hintz Alumni Center, between 6 and 9 pm. Penn State CAV researchers, working with counterparts at AFRL and Sandia, developed a new two Our corporate sponsors, government guests, and inter-national liaisons will cast votes for the best posters, and we’ll award small pr