2nd International Conference on Production and Industrial Engineering CPIE-2010

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1 nd International Conference on Production and Indutrial Engineering CPIE- 59 Actie/Paie Damping Technique for iration control: - FEM aed deign and experimental iration control Sanji Kumar Raji Kumar Rakeh Sehgal 3 Lecturer, BBSB College of Engg andtech., Dept of Mech. Engg., Fatehgarh Sahi,INDIA Aociate Profeor, Dept of (I & P) Engg. National Intitute of Technology, Jalandhar(Punja),INDIA 3 Profeor, Dept of Mech. Engg. National Intitute of Technology, Hamirpur, INDIA Atract: - Actie contrained layer damping treatment uffer from the diadantage of reduced tranmiiility of actie force. By uing edge anchor, thi prolem can e oled up to certain extent. Thee edge tiffener increae the tranmiiity of force only at ery high feedack gain only; howeer decreae the effectiene of PCLD treatment. On the other hand, y adding the tand off layer (SOL) etween the Vicoelatic layer and the ae eam, the efficiency of paie damping can e improed dramatically. Thi technique ha additional adantage. Firt, it increae the Vicoelatic train and hence more energy i diipated ia Vicoelatic layer. Secondly, it enhance the effect of actie force and moment een without uing edge anchor. The propoed treatment ha alo een erified experimentally. Keyword: - PCLD, ACLD, finite element method, iration control. INTRODUCTION AND PROBLEM FORMULATION Reearcher hae een intenifying oer the pat two decade regarding actie iration control method for tructure uing mart material. The potential and uitaility of uing mart compoite tructure for actie uppreion of iration in aeropace indutry i a widely inetigated topic of reearch. The widely ued mart material for iration control in tructure are piezoelectric material ince they hae deirale characteritic. Paie contrained layer damping (PCLD) i an old technique to uppre iration. In comination with actie control technique, PCLD treatment can e made een more effectie. Thi technique i called actie contrained layer damping (ACLD) treatment. Preent work i aed on the deelopment of newer paie

2 nd International Conference on Production and Indutrial Engineering CPIE- 597 technique, which can enhance the damping performance of PCLD and ACLD ytem. Firt of all the rief hitory of PCLD and ACLD treatment will e dicued. The ACLD treatment i uually a three layer compoite coniting of a Vicoelatic Material (VEM) damping layer andwiched etween a piezoelectric layer (contraining layer) and the aic tructure. The application of ACLD treatment for iration uppreion in tructure ha een exteniely inetigated y numerou reearcher. Swallow [] firt introduced the concept of tructural iration reduction with contrained layer damping treatment. A large amount of work ha een pulihed ince late 95 on the iration damping of three layer plate and eam. Reference [- 8] how the initial deelopment in thi area. Whittier [9] propoed that the hear angle of the VEM layer could further e increaed uing a SOL layer or pacer layer to the PCLD treatment etween the irating tructure and the contraining layer. Thi SOL layer moe the VEM layer and contraining layer farther from the neutral axi of the irating tructure. Thi diplacement which the SOL layer impoe magnifie the hear train in the VEM layer and thu it energy diipation. If the SOL layer itelf i choen to hae internal damping propertie, the oerall damping of the treatment may increae dramatically.. SYSTEM DESCRIPTION AND MODELING. Baic Relationhip The enhanced ACLD treatment with SOL layer i termed a EACLDSOL. The chematic of EACLDSOL i hown in figure (). The new thing here i that the additional SOL layer ha een andwiched. The upper urface of hot tructure or the eam i attached with a SOL and VEM layer. Thi layer in turn i contrained y an actie piezoelectric material like Lead Zirconiated Titnate (PZT). Thi layer act a an actie layer. A Polyinilidene Di Fluoride (PVDF) layer act a enor. A pair of edge element mounted at oth end of the contraining heet to connect the contraining layer directly to the hot tructure. Thee edge element are modeled a pring. Thee are alo called anchor. The purpoe of thee element i to increae the tranmiiility of the actie control action. Figure Nodal diplacement of a treated eam element For the continuity of diplacement at the interface etween the layer the relation etween hear angle (train) and ariou diplacement (figure ) i a [3]

3 nd International Conference on Production and Indutrial Engineering CPIE- 598 (h +h ) () (u +u ) (h -h -h ) () u -u h +h +y h c u =u - θ c c u = + θ c c = θ - h h h (3) where h h=y c + h +h + and θ denote the lope. u and w denote the longitudinal and tranere diplacement repectiely. h c, h, h and h denote the thickne of contraining layer, ae eam, VEM layer and SOL layer. The ditance etween the top urface of the ae eam and the neutral axi of the oerall ytem i denoted y y. The hear tre deeloped in VEM layer i denoted y τ. The hear train of the VEM layer i repreented y. Similarly hear tre deeloped in SOL layer i denoted y τ. The hear train of the SOL layer i repreented y. u c and u are the longitudinal diplacement of the contraining layer and the ae eam repectiely and w i the tranere diplacement of the contraining layer a well a of the ae eam. The edge tiffener are modeled a pring of certain tiffne. The hear tre in oth the layer i gien a = G and = G (a, ) Since equal tre i deeloped in oth the layer, hence = (5) Relation () and (5) how that = G VEM layer PZTActuator Layer G Figure Schematic of the experimental etup Soling equation () and (-5), we get uc-u h c+h +y w G h G = h h x G h G () uc-u h c +h +y w h G = h h x h G (7) The cloed loop equation of motion for the ytem i gien a MU + K+G U = SOL layer Viration Exciter p PVDF Senor Layer Treated Beam (Simply Supported) Bolt Attachment Soft Material High Voltage amplifier Channel High Voltage amplifier Channel Low Pa Filter Phae Change y inerting Spectrum Analyer (8)

4 nd International Conference on Production and Indutrial Engineering CPIE- 599 The chematic of the experimental etup i hown in figure (). Figure (3) how the photograph of the experimental eam. Figure 3 Photograph of the experimental eam The eigenalue prolem aociated with eq. (8) i * M ω K+G p U = (9) The eigenfrequencie will e complex ince there i a complex hear modulu in VEM and SOL layer material. After the complex eigenfrequencie hae een found, the modal frequencie and the lo factor of the ytem can e calculated a follow Im (ω ) * * ω= Reω, η= Re (ω * ) 3. Reult and dicuion (a, ) 3.. Performance with the addition of SOL Layer to Paie Contraining Layer Damping Treatment In the preent work, a SOL layer i added on the ae eam and after that the VEM layer i pated on it. The contraining layer i then glued on the VEM layer. If the material of the SOL layer i ame a of VEM layer, it will increae the thickne of VEM layer. It will decreae all modal lo factor except the firt mode. The improement for thi mode i only up to certain limit and after that damping performance decreae. It i not deirale. But, y increaing the Modulu of Rigidity (hear modulu) of the SOL layer, damping performance i enhanced dramatically. It i clear from the figure that optimal reult are otained if the modulu of rigidity of SOL layer i time that of VEM layer. An increae in lo factor y 8%, 5%, % and % for firt, econd, third and fourth mode repectiely wa otained. 3.. Performance with the addition of SOL Layer to Actie Contraining Layer Damping Treatment Now we are conidering the ACLD ytem with SOL layer. Figure () how the comparion of actie and paie lo factor for firt mode a a function of poition of ACLD patch (with and w/o SOL layer ) at different tiffne of anchor with 33 % coerage and Kp =. Figure (5) how Comparion of actie and paie lo factor for econd mode a a function of poition of ACLD patch (with and w/o SOL layer ) at different tiffne of anchor with 33 % coerage and Kp =. Firt and Second modal lo function are function of poition of ACLD patch (Figure ).. Concluion:- Application of tand off layer in-etween the ae eam and the Vicoelatic layer not only improe the damping performance of the paie

5 nd International Conference on Production and Indutrial Engineering CPIE- contrained layer damping treatment, ut alo of the actie contrained layer damping treatment. Ue of anchor can increae the modal lo factor in certain ituation with hear modulu of the SOL layer in the range 8 to 9 ; the enhancement in tranmiiity of force i ignificant, which i a remarkale factor in actie contrained layer damping treatment. Reference []. Swallow W. An improed method of damping panel iration. Britih Patent Specification 939; 53 []. Kerin EM. Damping of flexural wae y a contrained icoelatic layer. J Acout Soc America. 959; 3; 95-9 [3]. Ro D, Ungar E and Kerin EM. Damping of plate flexural iration y mean of Vicoelatic laminae. Structural damping New York ASME 959 []. Di Taranto RA. Theory of iratory ending for elatic and Vicoelatic finite length eam. J Appl Mech Tran ASME 95; 3: [5]. Mead DJ and Marku S. The force iration of a three layer damped andwich eam with aritrary oundary condition. J Sound Vi 99; : 3-75 []. Yan MJ and Dowell EH. Goerning equation for irating contrained layer damping of andwich eam and plate. J Appl Mech Tran ASME 97; 9: -7 [7]. Mead DJ. A comparion of ome equation for the flexural iration of damped andwich eam. J Sound and Vi 98; 83(3): [8]. Huang SC, Inman DJ and Autin EM. Some deign conideration for actie and paie contrained layer damping treatment. Smart Mater Struct 99; 5 : 3-33 [9]. Whittier JS, The effect of configurational addition uing Vicoelatic interface on the damping of a cantileer eam, Wright Air Deelopment Center WADC Technical Report 959: 58-58

6 MAXIMA NODE MAXIMA Second Modal Lo Factor MAXIMA Firt Modal Lo Factor nd International Conference on Production and Indutrial Engineering CPIE- TOTAL LOSS FACTOR OF ACLD SYSTEM WIthout SOL LAYER.3. SOL layer thick =mm SOL layer thick =mm SOL layer thick =3mm SOL layer thick =mm Anchor =zero N/m. Anchor =e N/m Anchor =e7 N/m x ACTIVE PORTION OF THE LOSS FACTOR OF ACLD SYSTEM..... PASSIVE PORTION OF THE LOSS FACTOR OF ACLD SYSTEM Ditance of the firt edge of the patch from the free end of the ae eam (mm). Anchor =zero N/m Anchor =e N/m.5 Anchor =e7 N/m x -3 x Ditance of the firt edge of the patch from the free end of the ae eam (mm) Figure. Comparion of actie and paie lo factor for firt mode a a function of poition of ACLD patch (with and w/o SOL layer ) at different tiffnee of anchor with 33 % coerage and Kp = Figure 5 Comparion of actie and paie lo factor for econd mode a a function of poition of ACLD patch (with and w/o SOL layer ) at different tiffnee of anchor with 33 % coerage and Kp =

7 IInd Modal Lo Factor It Modal Lo Factor nd International Conference on Production and Indutrial Engineering CPIE-.5 Anchor =zero N/m Anchor =e N/m. Anchor =5e N/m Anchor =e7 N/m Kp= 5 5 Kp=8 Kp= Kp= Ditance of the firt edge of the ACLD patch from the free edge of the ae eam (mm) with SOL a mm Kp= Figure Firt and Second modal lo function a a function of poition of ACLD patch (with SOL layer thickne a mm) at different tiffne of anchor at different feedack gain Kp with 33 % coerage