of computer based techniques, as well as laser-optics methods, nanotechnologies and nanomaterials, among many other technological advances, added new dimension and perspectives to minim ize or prevent catastrophic failures of engineering systems, structures and components.
This volume contains the extendedAbstracts of the 380 papers accepted for presentation in the IRF2013-41h International Conference on In tegrity, Relia bility and fa ilure held in Funchal/Portugal, 23-27 June 2013. The book is complemented by an accompanying CD-ROM containing the full length papers.
799 RO I R03 R05 807 809 RI I SI3 815 RI7 819 821 823 R25 827 829 13
EDlTORS PREFACE
As the engineering community continues lo cross the boundaries Df known practices, materiais and manufacturing techniques into lhe frontiers af new functional materiais, environrnents and applications. the opportunities for catastrophic failures w ill inevitably incrcase.
Ir
our knowledge af how to engineer systems, slTUctures and components to minimize or prevent catastrophic failure is to keep pile e with modem manufacturing technologies, the demanding applications, and the intolerance af a safety conscious society, we musl continue aur efforls to develop and use superior materiais, apply reliable analytical techniques and validate lhese with sound experimental tools. lt is with this in mind that lhis series of conferences was organised.The objectives of this gathering are to provi de a forum for the discussion and dissemination of recent advances in assessing the integrity, reliabilily and failure of engineering structurcs, components, and assemblies, foster research in these arcas, and promote international co-operation arnong scientists and engineers in the field . The goal is to enable concerncd researchers and scientists from ali over the world to exchange ideas on mechanics, materiais and design as Ihey relate lo system integrily and reliabilily.
This fourth intemational conference, which is sponsored by the Univcrsity Df Porto, lhe University ofToronto and the University of Madeira, is part ofa prestigious series of Integrity Reliability and Failure conferences coordinated by the Intemational Scientific Committee on Mechanics and Materiais in Design. The conference atlractcd over 300 participants with 380 accepted submi ssions [rom 45 different countries around lhe world. These papers were presenled in June 23-27, 2013 in lhe magnificenl cily of Funchal, Madeira. The confcrence themcs which address integrity, reliability and failurc focu sed on Analytical and Numerical tools, Testing and Diagnostics, Surfacc and Interface Engineering, Sensors and Instrumentation, Tribology, Mechanical Design and Prototyping, Modes of Failure, Composite Materiais, Nanotcchnologies and Nanornaterials, Biomechan ícs, Energy and Thenno-Fluid Systems, Impact and Crashworthiness and Case Studies.
We are particularly indebted lo the authors and speeial gucsls for their plcnary lectures and presentations. Each of lhe more than 380 contributions offered opportunities for thorough discussions with the authors. We acknowledge ali of the participants, who contributed with innovations, new research approaches, novel modeling and simulation efforts, and invaluable criticai commems. We are also indebled to lhe outstanding plcnary lecturers who highlighled the conference thcrnes with their contributions: Professor Xiong Zhang (Tsinghua University, P. R. China), Professor E.A. Elsayed (Rutgers University, USA) and Professor Norilsugu Umehra (Nagoya University, Japan). We also take this opportunity to thank lhe members of lhe Intemational Scientific Committee and reviewers for thcir time and effort.
Last but by no means least, we offer our sincere gratitudc to the symposia organisers [ar th cir contribution to the success of the cvent and lhe local organising commíttec for attending to many aspeels oflhe conference dcmands. For ali ofthem, wc are truly very grateful.
Shaker A. Meguid alld J.F. Silva Gomes Fundlal ! Madeira, June 2013
International Scientific Committee
Abcn, H. (Estonia) Dourado, N. (Portugal) Masato, Y. (Jap'lIl) Sainov, V. (Bulgaria) Abreu, M.J. (portugal) Ebcrhardsteincr, J. (Austria) Mcda, A. (tlnly) Santos, J.M. (Portugal) Adali, S. (5. Africa) Estcvcs, l.L. (Portugal) Mcguid, S.A. (e:mada) Santos, Telmo (Portugal) Afonso, C.F. (Portugal) Fanguciro. R. (Portugal) Melo, F.Q. (Portugal) Serncnski, D. (Croatia) Alcxopoulos, N. (Grecec) Fernandes, A.A. (Portugal) Milciko, S.T. (Russia) Silva, AJ. (Portugal) Alves, A. (Portugal) Ferreira, D. (Portugal) Millcr. R.E. (Canada) Silva. Lucas (Portugal)
António,
c.c.
(Portugal) Ferreira, J.G. (Portugal) Mines, R. (UK) Silva Gomes, l.F. (Portugnl) Banks-Sil1s, L (Israel ) FiúZll, A. (Portugal) Miranda, R. (Portugal) Sjõdahl, M. (Sweden) Baptista, J.S. (Portugal) Fonseca E. (Portugal) Morcim, F. (Portugal) Soares, C.M. (Portugal) Barros, R.C. (Portugal) Gdoutos, E. (Grecce) Moreira, P. (Portugal) Sousa, LC. (Portugal) Bathe, K.1. (USA) Gcraldes, M. (Portugal Morimoto, Y. (Japan) Sousa, R. (Portugal) Botsis, J. (Switzcrli,lnd) Guedes, R.M. (Portugal) Moura, M.F. (Portugal) Suleman, Afzal (Portugal) Brcrnand, F. (Franee) Hejum, Ou (Singapore) Muc, Aleksander (Poland) Takagi, T. (Japan) Caetano, E. (Portugal) 19artua, A. (Spain) Navarro, C. (Spain) Talllia, M. (Portugal) ClImllnho, P. (Portugal) Ignaszak, Z. (Poland) Navas, H. (Portugal) Tamalsky, E. (Bmzil) Campos, lR. (Portugal) Iliescu, N. (Romania) Pappalettere, C. ([taly) Tamuzs, V. (Latvia) Castro, C.F. (Ponugal) Jones, N. (UK) Pieczyska, E. (Poland) Tavares, 1M. (Portugal) Castro, P.T. (Portugal) Jorge, R.N. (Ponugal) Piloto, P. (Portugal) Tavares, P. (Portugal) Catarino, A. (Portugal) Kahlen, F-J. (S. Africa) Pindera, M,J. (USA) Thomscn, O.T. (Denmark) Cavalcante, M. (Brazil) Klein, W. (Genmllly) Prime, M. (USA) Tooren, M,J. (Netherlands) Chen, T. (Taiwan) Kourkoulis, S. (Greece) Quc!has, O. (Brazil) TrumtlO, C.E. (UK) Chenot, J-L (France) Laermann, K. (Germany) Ramesh, K. (Jndia) VanHemc!rijck, D. (Belgium) Cime, J. (Portugal) Langseth, M. (Norway) Reddy, J.N. (USA) Varom, H. (Portugal) Correia, A. (Ponugal) Lima, G. (Brazi]) Restivo, M.T. (Ponugal) Vasques, C. (Ponugal) Croccolo, D. (ltaly) Lino, J. (Ponugal) Ribeiro, J.E. (Portugal) Vaz, Mnrio P. (Ponugal) Cunha, A. (Ponugal) Lopes, H. (Ponugal) Robinson, J. (Ircland) Vilas-Boas, l (Portugal) Daua, S. (USA) Lu, Jian (I~ong Kong) Rocha, A.B. (Portugal) Wang, Wci-Chung (Taiwan) Degrieck, J. (Belgium) Madureira, L (Portugal) Rodrigues, H. (Portugal) Weng, G. (USA)Dias, G. (Ponugal) Maia, Lino (Portugal) Rodrigues, lO. (Portuglll) Yoneyama, Satoro (Japan) Dietrich, L. (Poland) Mal, A. (USA) Ruiz, G. (Spain) Yoon, Y.C. (Singapore) Diago, M.T. (Portugal) Marques, A.T. (Portugal) Ruzieka, M. (Czech R.l Zhang, Z. (China)
J)
Institutional Sponsors
FEUP
MADL
CCEE
Ul1iversily Df Porto Portugal
Ulliversity ofToronto Callada
University of Madeira Portugal
Co-Chairs
J.F. Silva Gomes
CU.
PorIa)
Shaker A. Meguid
C U.Toronto)
Organizing Committee
Carlos C. Antánio, CHto F. Afonso, José M. Cime
Lino Maia, Mário A.P. Vaz, Paulo G. Piloto, Pedro M.G.P. Moreira
Conference Secretariat
Nuno Pinto, Lurdcs Calalino, Carla Gonçalves M.F. Silva Gomes,
lVi/h lhe mppor/ of
ABREU-pea, Profcssional Congress Organizcr (http://pco.abrcu.pt) Mcrcatura Confcrcncc Systcrn (http://www.mcrcatura.pt)
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ACKNOWLEDGMENTS
IRF2013 confercnce is sponsored by the following institutions, whose contributions are gratefully acknowledged:
FEUP-Faculdade de Engenharia, Universidade do Porlo MADL-Mechanics Gnd Aerospace Design Lab, Universily ofToronto CCEE-Cenlro de Ciências Exae/as e de Engenharia, Universidade da A1adeira
Governo Regional da Madeira
IVBAM-lllstitllto do Vinho, do Bordado e do Artesanato da Madeira, !.P. APAET-Porlugucse Associatioll for Experimental Mechanics
EURASEM-El/ropean Sacie'y for Experimental Mechanics SEM-American Saciely for Experimental Mechanics
BSSM-British Saciely for Stl'ain A1easuremenl JSME-Japallcse Society of Mechanical Engilleering
IMEKO-Inlernational Measuremenl Conjederation AFM-Associatioll Française de MécGnique DY.MAT-EuropeaJl Associationjor Dynamics of Materiais INEG1-lnstitulo de Engenharia Mecânica e Gestão Industrial
LABIOMEP-Laboralório de Biomecânica do Porto FCT-Fundação para a Ciência e a Tecnologia ABREU-PCO, Professional Congress Organize/'
(grORTO
••••••••
••••••••
MEDiANlCS ANO AEROSPACE DE5IGN lAB---
.. t11.
~ i-;'-TRACKS I MAIN TOPICS:
Topic_ A: Analytical and Numerical 1001s
Topic_B: Testing and Diagnostics
Topic_ C: Surface and lnterlàce Engincering Topic_D: Civil Engineering Applications Topic_ E: Sensors and Instrumentation Topic_ F: Tribology, Geurs and Transmissions Topic _ G: Mechanical Design and Protolyping Topic _H: Modes af Failurc
Topic_I: Composite Materiais
Topic_J: Nanotechnologics and Nanomaterials Topic _ K: Biomechanical Applications Topic_L: Encrgy and Thenno-Fluid Systems Topic_M: Impact and Crashworthiness
Topic_N: Case Studies
SPECIAL SYMPOSIA:
Symp_OI: Smarl Materiais and Structures Coordinafor: MJ. Gera/des (UBI) Symp_03: lmaging and Vizualization
Coordinator: João Tavares (U.Porto)
Symp_04: OpticaI Techniques ofExperimental Mechanics in Dcsign
Coordinators: Hernani Lopes (lPB), João Ribeiro (IPB)
Symp_05: Blood Flow Mcchanical Behaviour
Coordinalors: Catarina Castro (U.Porto), Luisa Sousa (U.Porto)
Symp _ 06: Integrity, Reliability and Failure in Dental Materiais
Coordinalors: J.c. Reis Campos (U.Porlo), André Correia (U.Porto)
Symp_ 07: Mechanical Characterization ofBone Behaviour
Coordinators: Marcelo Moura (U.Porto), Nl11l0 Dourado (UTAD)
Symp _ 1o: Structural and Multidisciplinary Optimization
Coordinalor: Carlos C. António (U.Porto)
Symp _ 11: Innovative Joining Processes
Coordillalors: Pedro Moreira (lNEGl/ U.Porto), LlIcas Silva (U.Porto)
Symp _12: Vibration and Structural Acoustic Analysis
COOl'dinalor: César Vasqlles (INEGI)
Symp_ 13: Dynamics, Stability and Control in Engineering Structures
Coordinator: Rui C. Barros (U. Porto)
Symp 14: Assessment, Monitoring and Control ofCivil Engineering Structurcs
- Coordillalors: Álvaro Cunha (U.Porto), Eisa Caetano (U.Porto)
Symp_ 15: Behaviour Characterization ofConstructions for Earthquake Demands
Coordinators: Humberto Vantm (U.Aveiro), Hugo Rodrigues (U.Aveiro)
Symp_ 17: Concrete Material Perfonnance
Coordinators: Nuno Dourado (UTAD), Marcelo Moura (U.Porto)
Symp_J 8: Safety ofWooden Structures
Coordinalors: Elza Fonseca (IPB), Débora Ferreira (IPB)
Symp_ 19: Occupational Safety and Health
Coordinators: J. Santos Baptista (U.Porlo), M Tato Diogo (U.Porto), Gilson Lima (LATEC), Osvaldo Quelhas (LATEC)
Symp_20: Thclll10dynamics and Thenno-Fluid Systems
Coordiflators: Clilo F. Afonso (U.Porto), Carlos C. Anlól/io (U.Porlo)
Symp_21: Lean and Green Manufacturing
Coordinators: AI/abeta Alves (U.Minho), Rui SOl/sa (U. Minho), Franz-Josef Kallen (U. Cape Town)
Symp_26: Advanccs in Fibrous and Composite MateriaIs for Civil Engineering
Coordillators: Raul Fanglleiro (U. Minha), Sohel Rana (U.Minho)
Symp_27: Structural Health Monitoring of Advanced Structures
Coordinators: Júlio C. Viana (CriticaI MateriaIs, SA), Gustavo Dias (CriticaI Malerials, SA)
Symp_28: Fire and StructuraI Engineering
Coordinators: Paulo G. Piloto (IPB), Alberto Medo (U. Roma)
Symp_29: Metrology, Quality Contrai and Reliability
Coordinator: Helena v.G. Novas (FCT/ UNL)
Symp_30: MedicaI Devices and Healthcare Materiais
Coordinators: Maria José Abreu (U.Minho), André Calarino (U.Minha)
Symp_31: Micromechanics and Homogenization af Hctcrogeneous Media
Coordinalors: Marek-Jerzy Pindem (U. Virginia), Marcio Cavalcante (U.Alagoas)
Symp_32: Failure and Fatigue ofStructural Elements
Coordinator: Aleksander Muc (Cracow U.T.)
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RECENT ADVANCES IN
INTEGRITY -RELlABILlTY -FAILURE
J.F. Silva Gomes, Shaker A. Meguid (Ed)
Proceedings IRF2013
4th International Conference on Integrity, Reliability and Failure
FunchallPortugal, 23-27 June 2013SYMPOSIUM_18
Safety Df Wooden Structures
Coordinators: Elza M.M. Fonseca")
Departmenl af Applied Mechanics, Polylechnic Institule of Bragança. Portugal
Débora RS.M. Ferreira" )
Departmenl of Applied Mechanics, Polytechnic Institule Df Bragança, Portugal
d, :n s, 1e lO he :es lal ,w ón y nd ral ns, Jl3
fNTEGRlTY, RELfABfLfTY AND FAfLURE
PAPEl< REF: 4057
NUMERICAL MODEL TO EV ALUA TE THE FIRE RESIST ANCE
IN WOODEN SLABS WITH CA VITIES
D. Coelhol
('), E.M.M. Fonseca!, P. Vila Rcal\ J.A. Faria!, A. Aredc·
I Faculty ofEnginccring, Univcrsity
ar
Porto, Porto, Portugal~Polytcchnic Institulc ofSragança, Bragança, Portugal
JUniversity af Avciro, Avciro, Portugal
(O)Email: diana.coclho@gmaiLcom
ABSTRACT
The main objective af this paper is to develop a numerical madel for thermal analysis Df wooden slabs with cavities, when subjected to the fire action. The temperature profiles, the charring deplh layer and lhe charring rate will be determined using lhe finile element method with ANSYS program, The numerical calculation of the temperature profiles will be obtained through a transient and a noo-linear thermal analysis, where the material properties are tcmperature dependent. These properties were established in accordance with the referenced data and numerically calibrated. Two different models of wooden slabs with cavities were studied. Ooe modeI characterizes a wood slab with void cavities and other with insulation material. To characterize the fire resistance in wooden slabs with insulated cavities or void cavities, different typical curves of charring depth layer will be obtained. A numerical procedure is proposed to identify the heating action into the slab cavities. Ali numerical results pennit the verification ofthe fire safety in wooden slabs with cavities.
Keywords: wooden slab, fire, insulated cavities, void cavities.
INTRODUCTION
Wood is a friendly material, attracted by engineers and architects, due the attractive attributes such as architectural features, structural characteristics and a1so a renewable material. This material when exposed to accidental actions, such as fire action, presents a decomposition process, pyrolysis, and produces a surrounding charring depth layer. On the fire exposure side a charcoal layer, without effective resistance, causes the reduction of the element cross-section. However, this charring depth layer can delay the heating process, from the exposed side, lo the wood core section and acting as a good insulating material. Several researchers have presented experiínental models and analytical methods to calculate the physical degradation of ,wood due high temperatures (White, 1999), (Poon, 2003), (lanssens, 2004), (Frangi, 2008), The main objectives ofthis work are:
- Present a numerical mode! to obtain the sarne results from Frangi when uses experimental wooden slabs;
- Evaluate the thennal perfonnance of wooden slabs with insulated cavities or void cavities, when subjected of a fire situation;
- Determine different stages of the charring rate Ihrough ali wooden slabs;
- Present a numerical model who intends to be a replica of prefabricated wooden slabs common in Nordic countries, and used in residential and commercial buildings;
4111 l11ternot;onal Conference onlntegrity , Reliability ol1d Fai/llre
- Use two different insulated materiais (glass fiber and rock waol) in arder to evaluate the thennal effect into lhe wooden slab cavities.
RESULTS AND CONCLUSIONS
This study considers a replica of a prefabricated wooden slab with cavities exposed to fire, with two constructive solutions, figure I. In lhe first solutiont lhe slab cavities have an
insulation materialt and for the second solution the internai slab cavities have no insulation.
These models were based on lhe conslructivc solution proposed by Frangi. The numerical
model proved to be a great importance in the detennination of the charring depth layer in
wooden slabs with insulatcd cavities and void cavities. The temperature profiles obtained in transient analysist as well as lhe charring rate in different phases in wooden slabs with cavities
exposed to fire were calculated using the finite element melhod with ANSYS programo Two
different insulation materiais used into lhe wooden cavities were compared and the mineral
wool exerts higher proleclion in relation to the fiber glass, figure 2a. The results obtained through lhe proposed numerical model have a good correlation between lhe values of Frangi and Eurocode 5. As regards with the study ofthe wooden slab with void cavities, it is possible
to conclude that at the end af one hour of fire exposure, lhe structural resistance vanishes
completely, as represented in figure 2b.
I '
Fig. I - Prefabricated wooden slab with insulalcd and void cavities dimensions in mm.
;;:~ 1.::: .:::: :;;: JH. ';H ;;:':a . " l : n.U!
~ 1 . l!1l JJ1. 111 ll !.~ ~ ' ;;:J7 . 17 ~ 1~ =
Fig. 2 - Tempcralurcs in woodcn slab wilh insulated and void cavitics at the end of 3600s.
REFERENCES
[I)-White RH, Dietenberger MA. Fire Safety, Chapter 17, Wood Handbook: Wood as an Engineering Material, Forest Products Laboratory, USDA Forest Service, 1999.
[2)-Poon L, England JP. Literature Review on the Contribution of Fire Resislant Timber Construction to Heat Release Rale - Timber Development Association, Warrington Fire Research Aust. Pty. Ltd., Project No.20633, version 2b, pp.I-78, 2003.
[3)-Janssens ML. Modeling of the lhennal degradation of structural wood members exposed to fire. Fire and Materiais, 28, pp.199-207, 2004.
[4)-Frangi A, Knobloch M, Fontana M. EIsevier - Fire design oftimber slabs made ofhollow core elements. EIsevier - Engeneering Structures, USA, 2008.
