PRELIMINARY ANALYSIS ON THE INFLUENCE OF THE LINK CONFIGURATION ON SEISMIC PERFORMANCES OF MRF-EBF DUAL SYSTEMS DESIGNED BY TPMC

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1 Intrnational Journal of Earthquak Enginring Num. Anno XXXIII Spcial CTA Num. PRELIMINARY ANALYSIS ON THE INFLUENCE OF THE LINK CONFIGURATION ON SEISMIC PERFORMANCES OF MRF-EBF DUAL SYSTEMS DESIGNED BY Rosario Montuori, Elid Nastri*, Vincnzo Piluso Dpartmnt of Civil Enginring, Univrsity of Salrno, Italy SUMMARY: Th work is dvotd to th valuation of th influnc of link configuration on sismic prformancs of Momnt Rsisting Frams-Eccntrically Bracd Frams dual systms (MRF-EBF dual systms) dsignd by mans of Thory of Plastic Mchanism Control (). As it is known assurs th dvlopmnt of a collaps mchanism of global typ, thrfor, th sismic prformancs valuatd by mans of IDA analyss, ar affctd only by th structural schm configuration. Howvr, in this papr only a bays structur with, and 8 storys ar rportd, so that, th work configurs as a prliminary valuation. Additional analyss on diffrnt structural schms with diffrnt numbr of bays will b th natural dvlopmnt of th work hrin prsntd. KEYWORDS: EBFs, ccntrically bracd frams, sismic, kinmatic thorm,. INTRODUCTION Th work hrin prsntd is dvotd to th valuation of th sismic prformanc of Momnt Rsisting Fram-Eccntrically Bracd Fram dual systms (MRF-EBF dual systms) considring all th possibl configuration of bracs and links as rportd in th Eurocod 8 [CEN, ] (Fig. ). As it is known, EBFs constitut a suitabl compromis btwn MRF and CBF [Longo t al., ; D Anillo t al., ; D Anillo t al., ; D Anillo t al., ], du both to thir latral stiffnss givn by th bracs and adquat dissipation capacity givn by links abl to dvlop wid and stabl hystrsis loops [Dlla Cort t al., ; Dlla Cort t al., 7]. Th numbr of th proposd link configuration is : thr of which hav a horizontal link configuration (K-schm, D-schm, V-schm) whil th last on has a vrtical link configuration (Invrtd Y-schm). In this papr, MRF-EBF dual systms with, and 8 storys hav bn dsignd using th Thory of Plastic Mchanism Control for a total numbr of study cass. Th scop is to invstigat th structural sismic rspons of th dsignd structur bing assurd, by th dsign approach, a collaps mchanism of global typ. In this way, th sismic prformancs ar only affctd by th structural schm, i.. by th link configuration. For this rason both push-ovr and Incrmntal Dynamic Analyss (IDA) hav bn carrid out on th dsignd structur with th scop to point out, on on hand, th accuracy of th dsign approach, and on th othr hand, downstram th validation, th diffrnt sismic prformancs achivd by th diffrntly configurd structur. Howvr, in this papr only a bays structur is invstigatd, so that th work configurs as a prliminary valuation. For a highr accuracy, additional analyss on diffrnt structural schms with diffrnt story and bay numbrs will b rportd in furthr works. *Corrsponding author: Elid Nastri, Dpartmnt of Civil Enginring, Univrsity of Salrno, Italy. nastri@unisa.it

2 INGEGNERIA SISMICA INTERNATIONAL JOURNAL OF EARTHQUAKE ENGINEERING Figur. EBFs typologis proposd by Eurocod 8. DESIGN APPROACH is basd on a rigorous approach assuring a collaps mchanism of global typ [Piluso t al., ; Montuori and Muscati, ; Longo t al., ] which xploits th kinmathic thorm of plastic collaps xtndd to th concpt of collaps mchanism quilibrium curv: () whr is th first ordr collaps multiplir of horizontal forcs, is th slop of th linarizd mchanism curv du to scond ordr ffcts and is th plastic top sway displacmnt. stats that th mchanism quilibrium curv corrsponding to th global mchanism has to b locatd blow thos corrsponding to all th undsird mchanisms until a dsign displacmnt compatibl with th local ductility supply (Figur ). Column sctions at ach story ndd to assur a collaps mchanism of global typ ar unknown of th dsign problm, whil link, bam and diagonal mmbrs ar prliminarily dtrmind as known quantitis of th dsign problm. Mor dtails about this dsign procdur dvotd to EBFs ar rportd in prvious works [Longo t al., ; Montuori t al., ; Montuori t al., a; Montuori t al., b; Montuori t al., ]. STUDY CASES Th study cass hrin invstigatd ar rfrrd to a building whos plan configuration is dpictd in Fig.. In particular, considring only th primtr frams whos scondary floor warping is orthogonal to th bam of th fram, four structurs hav bn dsignd for ach slctd numbr of story (, and 8) according to for a total numbr of frams. Th corrsponding sismic rsistant schms ar dpictd in Figur with rfrnc to th - story building whr also th laning column adoptd in structural modlling to account for scond ordr ffcts du to th intrnal gravity load rsisting systm is rportd. Rgarding th lngth of th links, at ach story, it is qual to. m for K-schm and D-schm EBFs whil is qual to. m for V-schm EBFs. As rgards th invrtd Y-schm, link lngth has bn assumd qual to m at ach story bcaus th link lngth has bn dfind in ordr to assur that th ultimat dsign displacmnt,, for th application of is th sam both for th all th structural configuration, according to th following rlations:.8./. for K-schm and D-schm ().8./.. for invrtd V-schm ().8.7/.. for invrtd Y-schm () whr is th targt link plastic rotation, is th link lngth, is th bracd bay lngth, is th intrstory hight and is th building hight.

3 R. MONTUORI t al. Figur. statmnt Th charactristic valus of th vrtical loads ar qual to. kn/m and. kn/m for prmannt and liv loads, rspctivly. As a consqunc, with rfrnc to th sismic load combination providd by EC8, (whr is th cofficint for th quasi-prmannt valu of th variabl actions, qual to. for rsidntial buildings), th vrtical loads acting on th floor ar qual to. kn/m. Th structural matrial adoptd for all th mmbrs is S stl grad. Th bams hav bn dsignd to withstand vrtical loads accounting also for srvicability rquirmnts and thy ar dlivrd in Figur. Th dsign horizontal forcs hav bn dtrmind according to EC8, assuming a pak ground acclration qual to.g, a sismic rspons factor qual to. and a bhaviour factor qual to. It is important to obsrv that EC8 dos not mak any diffrnc in trm of bhaviour factor btwn th EBFs configuration. On th basis of such forc distribution, th dsign shar action of link mmbrs has bn obtaind by assuming that th story shar is compltly ntrustd to th link. In addition, for ach structur th link lngth combind with th rsistanc blonging to th slction of th sction from th standard shap assur a shortlink bhaviour, according to th classification givn in EC8. Short links show many advantags if compard with long and intrmdiat links du to thir prformanc in trms of both stiffnss and ductility. In fact, th cyclic bhaviour of short links is charactrisd by wid and stabl cycls allowing th dvlopmnt of high nrgy dissipation capacity and highst rotational capacity if compard with long and intrmdiat ons [Bosco t al., ; Mastrandra t al., ; Ohsaki t al., ; Gulc t al., ]. Tabl th link and diagonal sctions for th dsignd structurs ar rportd. In addition, in th Tabl column sctions of ach structur ar dlivrd. For sak of shortnss, th numrical dtails for th application of procdur ar givn lswhr [Longo t al., ; Montuori t al., a; Montuori t al., b] so only th rsults obtaind ar hrin prsntd.. PUSH-OVER RESULTS With rfrnc to th sismic rsistant systm dpictd in Figur, push-ovr analyss hav bn carrid out by mans of SAP computr program for all th four structural schms. Th aim of ths analyss is to chck th collaps mchanism actually dvlopd in ordr to validat th accuracy of th application. Mmbr yilding has bn accountd for by modlling th dissipativ zons by mans of hing lmnts, i.. with a lumpd plasticity modl.

4 INGEGNERIA SISMICA INTERNATIONAL JOURNAL OF EARTHQUAKE ENGINEERING Column, bam, diagonal and link mmbrs hav bn modlld with an lastic bam-column fram lmnt with two rigid-plastic hing lmnts locatd at th mmbr nds. With rfrnc to bams, plastic hing proprtis ar dfind in pur bnding (M hing) whil in cas of columns and diagonals plastic hing proprtis ar dfind to account for th intraction btwn bnding and axial forc (P-M hings). Both of thm hav a rigid-plastic constitutiv modl for th momnt rotation bhaviour. In addition, an axial hing has bn locatd in th midspan of ach column with th scop to chck th out of plan buckling. Rgarding link mmbrs, as short links yilding in shar ar of concrn, plastic hings in shar hav bn considrd with a shar forc vrsus shar displacmnt rigid-hardning constitutiv modl (. of ovrstrngth). Figur. Plan configuration of th analysd structurs Tabl. Dsign sismic forcs, link and diagonal sctions for th dsignd structurs K-schm D-schm V-schm Invrtd Y-schm F [kn] LINKS DIAGONALS LINKS DIAGONALS LINKS DIAGONALS LINKS DIAGONALS 9.97 HEB CHS.9x HEB CHS.9x HEB CHS.9x HEB CHS.x 9.9 HEB CHS.9x HEB CHS.9x HEB CHS.9x HEB CHS.x 88.9 HEB 8 CHS.9x HEB 8 CHS.9x HEB CHS.9x HEB CHS.x 8.9 HEB CHS.9x HEB CHS.9x HEB CHS.9x HEB 8 CHS.x K-schm D-schm V-schm Invrtd Y-schm F [kn] LINKS DIAGONALS LINKS DIAGONALS LINKS DIAGONALS LINKS DIAGONALS. HEB CHS.x HEB CHS.x HEB 8 CHS.x HEB CHS.x.8 HEB CHS.x HEB CHS.x HEB 8 CHS.x HEB CHS.x.98 HEB CHS.x HEB CHS.x HEB 8 CHS.x HEB CHS.x.7 HEB CHS.x HEB 8 CHS.x HEB CHS.x HEB 8 CHS.x. HEB CHS.x HEB CHS.x HEB CHS.x HEB CHS.x.8 HEB CHS.x HEB CHS.x HEB CHS.x HEB CHS.x K-schm D-schm V-schm Invrtd Y-schm F [kn] LINKS DIAGONALS LINKS DIAGONALS LINKS DIAGONALS LINKS DIAGONALS.7 HE B CHS.x HEB CHS.x HE 8 B CHS.x. HEB CHS.x.89 HE B CHS.x HEB CHS.x HE 8 B CHS.x. HEB CHS.x 9. HE B CHS.x HEB CHS.x HE 8 B CHS.x. HEB CHS.x.978 HE B CHS.x HEB CHS.x HE 8 B CHS.x. HEB CHS.x 8.7 HE B CHS.x HEB 8 CHS.x HE B CHS.x. HEB 8 CHS.x 9.7 HE 8 B CHS.x HEB CHS.x HE B CHS.x. HEB CHS.x 7. HE B CHS.x HEB CHS.x HE B CHS.x. HEB CHS.x 8.9 HE B CHS.x HEB CHS.x HE B CHS.x. HEB CHS.x -STOREY -STOREY 8-STOREY

5 R. MONTUORI t al. MRF-EBF DUAL K-SCHEME - STOREYS MRF-EBF DUAL D-SCHEME - STOREYS =. kn = kn =8.8 kn = cm qd=(gk+.qk)l=.9 knm =(Gk+.Qk)Ll L= 9. knm =. kn = kn =8.8 kn = cm qd=(gk+.qk)l=.9 knm =(Gk+.Qk)Ll L= 9. knm HEB HEB 8 HEB HEB HEB HEB HEB HEB HEB HEB HEB C C C C HEB C C C C MRF-EBF DUAL K-SCHEME - 8 STOREYS MRF-EBF DUAL D-SCHEME - 8 STOREYS =. kn = kn =8.8 kn HEB HEB HEB 8 HEB HEB HEB HEB HEB = cm qd=(gk+.qk)l=.9 knm C C C C =(Gk+.Qk)Ll L= 9. knm 8 7 =. kn = kn =8.8 kn HEB HEB HEB 8 HEB HEB HEB HEB HEB = cm qd=(gk+.qk)l=.9 knm C C C C =(Gk+.Qk)Ll L= 9. knm MRF-EBF DUAL V-SCHEME - STOREYS MRF-EBF DUAL INVERTED Y-SCHEME - STOREYS =. kn = kn =8.8 kn = cm qd=(gk+.qk)l=.9 knm =(Gk+.Qk)Ll L= 9. knm =. kn = kn =8.8 kn =7 cm qd=(gk+.qk)l=.9 knm =(Gk+.Qk)Ll L= 9. knm HEB HEB HEB HEB HEB 8 HEB 8 C C C C C C C C MRF-EBF DUAL V-SCHEME - 8 STOREYS MRF-EBF DUAL INVERTED Y-SCHEME - 8 STOREYS =. kn = kn =8.8 kn = cm =. kn = kn =8.8 kn =7 cm qd=(gk+.qk)l=.9 knm =(Gk+.Qk)Ll L= 9. knm qd=(gk+.qk)l=.9 knm =(Gk+.Qk)Ll L= 9. knm HEB 8 8 HEB 7 7 HEB HEB HEB 8 HEB 8 HEB 8 HEB 8 C C C C C C C C Figur. Structral schms of th longitudinal sismic rsistant systm 9.

6 INGEGNERIA SISMICA INTERNATIONAL JOURNAL OF EARTHQUAKE ENGINEERING Push-ovr analyss hav bn ld undr displacmnt control taking into account both gomtrical and mchanical non-linaritis. In addition, out-of-plan stability chcks of comprssd mmbrs hav bn prformd at ach stp of th non-linar analysis for both th xamind structurs. Th rsults providd by th pushovr analyss ar rportd in Fig., Fig. and Fig. for th -story, -story and 8-story buildings, rspctivly. In particular, th rsults providd by th analyss show that th softning branch of th push-ovr curv corrsponding to th structur dsignd by mans of tnds towards th mchanism quilibrium curv obtaind by mans of scond ordr rigid-plastic analysis. It is also usful to undrlin that, in th xamind cass, push-ovr curvs xhibit a softning bhaviour, bcaus th occurrnc of strain-hardning in shar links dos not countrbalanc th softning du to scond ordr ffcts. Tabl. Column sctions -STOREY -STOREY BUILDING 8-STOREY BUILDING K-schm D-schm V-schm Inv. Y-schm C C C C C C C C R=HEB HEB 8 HEB 8 HEB HEB HEB HEB HEB HEB HEB HEB 8 HEB L=HEB R=HEB HEB 8 HEB 8 HEB HEB HEB HEB HEB HEB HEB HEB HEB L=HEB R=HEB HEB 8 HEB 8 HEB HEB HEB HEB HEB HEB HEB HEB HEB L=HEB 8 R=HEB HEB 8 HEB 8 HEB HEB HEB HEB HEB HEB HEB HEB HEB L=HEB K-schm D-schm V-schm Inv. Y-schm C C C C C C C C R=HEB HEB HEB HEB HEB 8 HEB 8 HEB HEB HEB HEB HEB HEB L=HEB R=HEB HEB HEB HEB HEB 8 HEB 8 HEB HEB HEB HEB HEB HEB L=HEB R=HEB HEB HEB HEB HEB 8 HEB 8 HEB HEB HEB HEB HEB HEB L=HEB R=HEB HEB HEB HEB HEB 8 HEB 8 HEB HEB HEB HEB HEB HEB L=HEB R=HEB HEB HEB HEB HEB 8 HEB 8 HEB HEB HEB HEB HEB HEB L=HEB R=HEB HEB HEB HEB HEB 8 HEB 8 HEB 8 HEB 8 HEB HEB HEB HEB L=HEB K-schm D-schm V-schm Inv. Y-schm C C C C C C C C R=HEB 7 HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB L=HEB 7 R=HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB L=HEB R=HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB L= HEB R=HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB L=HEB R=HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB L=HEB R=HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB L=HEB R=HEB 7 HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB HEB L=HEB R=HEB 8 HEB HEB HEB HEB HEB HEB 8 HEB 8 HEB HEB HEB HEB L=HEB 8 7

7 R. MONTUORI t al. st. K schm Top sway displacmnt (m)....8 st. V schm Top sway displacmnt (m)....8 Bas Shar (kn) ultimat dsign displacmnt Bas Shar (kn) ultimat dsign displacmnt Figur. Push-ovr curvs for -story structurs Bas Shar (kn) ultimat dsign displacmnt st. D schm Top sway displacmnt (m)....8 Bas Shar (kn) ultimat dsign displacmnt st. Invrtd Y schm Top sway displacmnt (m) IDA ANALYSES RESULTS Whil prvious works hav invstigatd th diffrnt prformancs achivd by th structur dsignd by mans of and EC8, pointing out th highr prformancs of dsignd strucuturs [Montuori t al., a; Montuori t al., b] th scop of th IDA analyss hrin carrid out is th valuation of th sismic prformancs of th structurs considring th four link configuration proposd by EC8 givn th numbr of storys givn th sam dsign approach. To this purpos IDA analyss hav bn carrid out on th sam structural modl alrady adoptd for push-ovrs by assuming a % damping according to Rayligh with th proportional factors computd with rfrnc to th first and third mod of vibration (Tabl ). Rcord-to-rcord variability has bn accountd for by considring rcordd acclrograms slctd from PEER data bas [Pacific Earthquak Enginring Rsarch Cntr]. Ths rcordd acclrograms hav bn slctd to approximatly match th linar lastic dsign rspons spctrum of Eurocod 8, for soil typ A. In addition, ach ground motion has bn scald to obtain th sam valu of th spctral acclration, Sa(T), corrsponding to th fundamntal priod of vibration T of th structur undr xamination; succssivly Sa(T) valus hav bn progrssivly incrasd. Th IDA analyss hav bn carrid out by incrasing th Sa(T)/g valu until th occurrnc of structural collaps, corrsponding to column or diagonal buckling or up to th attainmnt of th limit valu of th chord rotation of structural mmbrs that is assumd qual to. rad in th cas of bams, columns and diagonals and qual to.8 rad in th cas of links [CEN, ]. 8

8 INGEGNERIA SISMICA INTERNATIONAL JOURNAL OF EARTHQUAKE ENGINEERING st. K schm Top sway displacmnt (m) st. V schm Top sway displacmnt (m) Bas Shar (kn) Ultimat dsign displacmnt Bas Shar (kn) Ultimat dsign displacmnt Figur. Push-ovr curvs for -story structurs Bas Shar (kn) Ultimat dsign displacmnt st. D schm Top sway displacmnt (m) Bas Shar (kn) Ultimat dsign displacmnt st. Invrtd Y schm Top sway displacmnt (m) In Tabl, Tabl and Tabl 7 th Sa(T)/g valus corrsponding to th structural collaps for ach ground motion ar rportd. In particular, by comparing th avrag valu of th collaps Sa(T)/g it is possibl to obsrv that, givn th numbr of storys, th collaps condition is always achivd, first by th V-schm structurs followd by th D-schm structur and K- schm. Invrtd Y-schm structurs always confirm th bst prformancs which bcoms mor rlvant at th incrasing of th structural hight compard with th scond classifid of th list, i.. K-schm. It is also possibl to obsrv that th sismic prformancs of D-schm and V-schm dcras as far as th structural hight incras, thrfor it is prfrabl not to us D-schm and V-schm EBFs for tall buildings. Convrsly, invrtd Y-schm incras its prformancs as th numbr of story incras, that maks it mor suitabl to tall building application. Othr bnfits givn by invrtd Y-schm EBFs, not blonging to th bam mmbr, ar th chanc to b asily substitutd aftr dstructiv sismic vnts and to conciv th schm within th framwork of supplmntary nrgy dissipation stratgy [Castaldo, ; D Iuliis and Castaldo, ; Castaldo and D Iuliis, ; Palazzo t al., ; Castaldo t al., ], by substituting th vrtical link mmbr with dissipativ dvic, such as a friction dampr or hystrtic dampr, which is abl to xhibit a highly dissipativ bhaviour if compard with traditional link mmbrs[montuori t al., b; Nastri, ]. In addition, such link configuration can b suitabl also for th sismic rtrofitting of xisting buildings [D Anillo t al., ; Mazzolani t al., 9]. 9

9 R. MONTUORI t al. Bas Shar (kn) Ultimat dsign displacmnt 8 st. K schm Top sway displacmnt (m) Bas Shar (kn) Ultimat dsign displacmnt 8 st. D schm Top sway displacmnt (m) st. V schm Top sway displacmnt (m) Bas Shar (kn) Ultimat dsign displacmnt Figur 7. Push-ovr curvs for 8-story structurs Bas Shar (kn) Ultimat dsign displacmnt 8 st. Invrtd Y schm Top sway displacmnt (m) Givn th abov, it is possibl to conclud that all th EBF configuration show quit th sam prformancs for a lowr numbr of storys whil th diffrncs bcoms mor rlvant as th numbr of storys incrass. For this rason, a diffrnt bhavior factor for th diffrnt EBF configuration should b assumd. Howvr, in this papr only a bays structur with, and 8 storys hav bn invstigatd so that additional analyss on diffrnt structural schms with diffrnt numbr of bays should b carrid out in ordr to provid a mor xhaustiv rsarch. Tabl. First and third vibration mod priod of buildings dsignd STOREYS STOREYS 8 STOREYS EC8 EC8 EC8 T (s) T (s) T (s) T (s) T (s) T (s) T (s) T (s) T (s) T (s) T (s) T (s) K-schm D-schm V-schm Invrtd Y-schm

10 INGEGNERIA SISMICA INTERNATIONAL JOURNAL OF EARTHQUAKE ENGINEERING Tabl. Analyzd ground motion rcords Earhquak (rcord) Componnt [-] Dat [-] PGA/g [-] Lngth (s) Stp rcording (s) Victoria, Mxico Chihuahua) CHI 98//9..9. Coalinga (Slack Canion) H-SCN 98// Kob (Kakogawa) KAK 99//..9. Spitak, Armnia (Gukasian) GUK 988// Northridg (Ston Canyon) SCR 99// Imprial Vally (Agrarias) H-AGR 979// Palm Springs (San Jacinto) PALMSPR/H8 98/7/8... Santa Barbara (Courthous) SBA 978/8/..7. Friuli, Italy (Buia) B-BUI 97/9/..8. Irpinia, Italy (Calitri) A-CTR 98//..79. Tabl. S a (T ) valus corrsponding to th attainmnt of th collaps condition for th story structurs st. K-schm st. D-schm st. V-schm -story Inv. Y Sa(T ) Sa(T ) Sa(T ) Sa(T ) Coalinga.9 g g g.8 g Friuli, Italy.9 g.9 g. g. g Imprial Vally. g. g. g. g Irpinia, Italy. g. g.9 g. g Kob.8 g.9 g. g.9 g Northridg g. g. g.8 g Palm Springs g.8 g. g.8 g Santa Barbara.8 g g. g.9 g Spitak Armnia. g. g. g. g Victoria Mxico. g. g. g.8 g Man valu.89 g.8 g. g.9 g Tabl. S a (T ) valus corrsponding to th attainmnt of th collaps condition for th story structurs st. K-schm st. D-schm st. V-schm st. Inv. Y-schm Sa(T ) Sa(T ) Sa(T ) Sa(T ) Coalinga g g. g.8 g Friuli, Italy g g. g g Imprial Vally. g. g. g. g Irpinia, Italy.8 g.9 g. g. g Kob. g. g. g g Northridg. g. g. g g Palm Springs. g. g. g. g Santa Barbara. g.9 g. g.9 g Spitak Armnia. g. g. g. g Victoria Mxico. g. g. g. g Man valu. g. g. g.7 g

11 R. MONTUORI t al. Tabl 7. S a (T ) valus corrsponding to th attainmnt of th collaps condition for th 8 st. structurs 8 st. K-schm 8 st. D-schm 8 st. V-schm 8 st. Inv. Y-schm Sa(T ) Sa(T ) Sa(T ) Sa(T ) Coalinga g g. g.8 g Friuli, Italy.9 g.8 g. g. g Imprial Vally. g. g. g. g Irpinia, Italy g g. g.8 g Kob. g. g. g.9 g Northridg. g. g. g. g Palm Springs. g. g. g. g Santa Barbara. g. g. g g Spitak Armnia. g. g. g. g Victoria Mxico. g. g. g g Man valu. g. g. g.8 g. CONCLUSIONS In this papr, th valuation of th influnc of link configuration on sismic prformancs of Momnt Rsisting Frams-Eccntrically Bracd Frams dual systms (MRF-EBF dual systms) dsignd by mans of Thory of Plastic Mchanism Control () is rportd. is basd on th kinmatic thorm of plastic collaps and its xtnsion to th concpt of mchanism quilibrium curv and assur to dsign structur showing at th collaps a global mchanism. For this rason, bing assurd and vrifid th collaps mchanism of global typ through push-ovr analyss, IDA hav bn carrid out to chck th actual prformancs of th dsignd frams. Rsults show that V-schm structurs always show th wors prformancs which vn dcras as far as th numbr of story incras. On th contrary invrtd Y-schm confirms th bst prformancs. Notwithstanding, invrtd Y-schm incrass its prformancs as th numbr of story incrass, that maks this structural schm mor suitabl for tall buildings, whil all th horizontal link EBFs dcras or at last kp constant thir prformancs bing an incras of th numbr of storys. Howvr, in this papr only a bays structur with, and 8 storys hav bn invstigatd so that additional analyss on diffrnt structural schms with diffrnt numbr of bays should b carrid out in ordr to provid a mor xhaustiv rsarch. 7. REFERENCES Bosco, M., Marino, E.M., Rossi, P.P., (), Modlling of stl link bams of short, intrmdiat or long lngth, Enginring Structurs, Volum 8, Fbruary, Pags -8. Castaldo P, D Iuliis M. Optimal intgratd sismic dsign of structural and viscolastic bracingdampr systms. Earthquak Enginring and Structural Dynamics ;(): Castaldo P. Intgratd Sismic Dsign of Structur and Control Systms. Springr Intr-national Publishing: Nw York,. DOI.7/ Castaldo P., Amndola G., Palazzo B. () Sismic fragility and rliability of structurs isolatd by friction pndulum dvics: Sismic rliability-basd dsign (SRBD), Earthquak Enginring and Structural Dynamics, DOI:./q.798.

12 INGEGNERIA SISMICA INTERNATIONAL JOURNAL OF EARTHQUAKE ENGINEERING CEN (): EN 998--: Eurocod 8 - Dsign of Structurs for Earthquak R-sistanc. Part : Gnral Ruls, Sismic Actions and Ruls for Buildings", Comit Euro-pn d Normalisation, CEN/TC. D Anillo M., Dlla Cort G., Mazzolani F.M., (). Sismic Upgrading of RC Build-ings by Stl Eccntric Bracs: Exprimntal Rsults vs. Numrical Modling. STESSA. Confrnc Stl Structurs in Sismic Ara. Japan, -7 August D Anillo M., La Manna Ambrosino G., Portioli F., Landolfo R., (). Modlling as-pcts of th sismic rspons of stl concntric bracd frams. Stl and Composit Structurs, An Intrnational Journal, Vol., No., 9- Novmbr D Anillo M., La Manna Ambrosino G., Portioli F., Landolfo R., (). Th influnc of out-ofstraightnss imprfction in Physical-Thory modls of bracing mmbrs on sismic prformanc assssmnt of concntric bracd structurs. Th Structural Dsign of Tall and Spcial Buildings, Vol. (), D Anillo M., Portioli F., Landolfo R., (). Modlling issus of stl bracs undr xtrm cyclic actions. COST- Final Confrnc Napls -8 Sptmbr; pp. -. D Iuliis M, Castaldo P. An nrgy-basd approach to th sismic control of on-way asymmtrical structural systms using smi-activ dvics. Inggnria Sismica - Intrna-tional Journal of Earthquak Enginring ; XXIX():. Dlla Cort G., D Anillo M., Landolfo R., (). Analytical and numrical study of plastic ovrstrngth of shar links. Journal of Constructional Stl Rsarch, 8, 9 Dlla Cort G., D Anillo M., Mazzolani F.M., (7). Inlastic rspons of shar links with axial rstraints: numrical vs. analytical rsults th Intrnational Confrnc on Advancs in Stl Structurs, Singapor, 7 Dcmbr. Gulc C.K., Gibbons B., Chn A., Whittakr A.S.: Damag Stats and Fragility Func-tions for Link Bams, Journal of Constructional Stl Rsarch, Vol. 7,, pp. 99-9,. Longo A., Montuori R., Piluso V. "Thory of plastic mchanism control for MRF CBF dual systms and its validation." Bulltin of Earthquak Enginring, pp. -,. Longo A., Nastri E., Piluso, V. [], Thory of Plastic Mchanism Control: Stat of th Art Th Opn Construction and Building Tchnology Journal,, 8: -78 Mastandra L., Nastri E., Piluso, V., Validation of a Dsign Procdur for Failur Mod Control of EB-Frams: Push-ovr and IDA analyss, Th Opn Construction and Building Tchnology Journal, 7, 9-7,. Mazzolani F.M., Dlla Cort G., D Anillo M., (9). Exprimntal analysis of stl dissipativ bracing systms for sismic upgrading. Journal of Civil Enginring and Managmnt (): 7-9. Montuori R., Muscati R., Plastic dsign of sismic rsistant rinforcd concrt fram, Earthquaks and Structurs, Vol. 8, No., January Pags -. Montuori R., Nastri E., Piluso V. (): Rigid-Plastic Analysis and Momnt-Shar In-traction for Hirarchy Critria of EB-Frams with Invrtd Y-Schm, Journal of Constructional Stl Rsarch, Volum 9, January, pp Montuori R., Nastri E., Piluso V. (a), Thory of Plastic Mchanism Control for Eccntrically Bracd Frams with Invrtd Y-schm, Journal of Constructional Stl R-sarch, Volum 9, January, pp.. Montuori R., Nastri E., Piluso V. (b) Thory of plastic mchanism control for th sismic dsign of bracd frams quippd with friction damprs - Mchanics Rsarch Communications Vol. 8. pp. -,.

13 R. MONTUORI t al. Montuori R., Nastri E., Piluso V., (a) Sismic Dsign of MRF-EBF Dual Systms with Vrtical Links: Ec8 Vs Plastic Dsign, accptd for publication on Journal of Earthquak Enginring,. Montuori R., Nastri, E., Piluso, V., (b) Sismic Rspons of EB-Frams with Invrtd Y schm: Vrsus Eurocod Provisions, accptd for publication on Earthquaks and Structurs. Montuori, R., Nastri, E., Piluso, V., Thory of plastic mchanism control for MRF-EBF dual systms: Closd Form Solution, Submittd for publication to Enginring Struc-turs,. Nastri E., Eccntrically Bracd Frams Dsignd for Enrgy Dissipation Optimization, ECCOMAS Congrss VII Europan Congrss on Computational Mthods in Ap-plid Scincs and Enginring, Crt Island, Grc, Jun. Ohsaki M., Nakajima T.: Optimization of Link Mmbr of Eccntrically Bracd Frams for Maximum Enrgy Dissipation, Journal of Constructional Stl Rsarch, Vol. 7,, pp. 8-,. Pacific Earthquak Enginring Rsarch Cntr, PEER Strong Motion Databas, Palazzo B, Castaldo P, Marino I. () Th Dissipativ Column: A Nw Hystrtic Dampr. Buildings;():-78; doi:.9/buildings. Piluso V., Nastri E., Montuori R., Advancs in Thory of Plastic Mchanism Control: Closd Form Solution for MR-Frams, accptd for publication on Earthquak Engi-nring and Structural Dynamics,

14 Intrnational Journal of Earthquak Enginring Num. Anno XXXIII Spcial CTA Num. ANALISI PRELIMINARE DELL INFLUENZA DELLA CONFIGURAZIONE NELLE PERFORMANCE SISMICHE DEI SISTEMI ACCOPPIATI CON CONTROVENTI ECCENTRICI PROGETTATI MEDIANTE LA Rosario Montuori, Elid Nastri*, Vincnzo Piluso Dpartmnt of Civil Enginring, Univrsity of Salrno, Italy SOMMARIO: Il lavoro riguarda l influnza dlla configurazion dl link nlla valutazion dll prstazioni sismich di tlai accoppiati con controvnti ccntrici (MRF-EBF dual systms) progttati mdiant la Toria dl Controllo dl Mccanismo di Collasso (). Com è noto, tal toria assicura ch i tlai progttati in accordo con ssa manifstino al collasso un mccanismo global. Pr tal motivo, con rifrimnto ai tlai riportati nl prsnt lavoro, l unico lmnto ch influnza l prstazioni sismich è la disposizion di link. In ogni caso, in qusta mmoria sono stat riportat l analisi push-ovr IDA pr una struttura a campat facndo variar il numro di piani (, 8). Essndo ssa solo un analisi prliminar risulta suprfluo affrmar ch una campagna di analisi più approfondita, riguardant struttur con divrso numro di piani di campat sarà oggtto di un futuro approfondimnto. *Corrsponding author: Elid Nastri, Dpartmnt of Civil Enginring, Univrsity of Salrno, Italy. nastri@unisa.it