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Modeling force transfer around openings in wood-frame shear walls / Minghao Li in Journal of structural engineering, Vol. 138 N° 12 (Décembre 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 12 (Décembre 2012) . - pp. 1419–1426 Titre : Modeling force transfer around openings in wood-frame shear walls Type de document : texte imprimé Auteurs : Minghao Li, Auteur ; Frank Lam, Auteur ; Borjen Yeh, Auteur Année de publication : 2013 Article en page(s) : pp. 1419–1426 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Wood  frame  Shear  walls  Openings  Force  transfer  Finite-element  model Résumé : This paper presented a modeling study on force transfer around openings (FTAO) in wood-frame shear walls detailed for FTAO. To understand the load transfer in the walls, this study used a finite-element model WALL2D, which is able to model individual wall components, including framing members, sheathing panels, oriented panel-frame nailed connections, framing connections, hold-down connections, and strap connections for reinforcing the corners of openings. The various wall models were validated through laboratory testing of 12 full-scale 2.44×3.66 m (8'×12') shear wall configurations, which included a variety of opening types and sizes. At the wall design load level, the predicted strap forces around openings also agreed well with the test results, in contrast with four simplified analytical methods commonly used in designing shear walls with openings detailed for FTAO. This wall model thus presents a useful tool to check the accuracy of the simplified methods and develop a better understanding of the behavior of wood-frame shear walls with openings. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000592 [article] Modeling force transfer around openings in wood-frame shear walls [texte imprimé] / Minghao Li, Auteur ; Frank Lam, Auteur ; Borjen Yeh, Auteur . - 2013 . - pp. 1419–1426. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 12 (Décembre 2012) . - pp. 1419–1426 Mots-clés : Wood  frame  Shear  walls  Openings  Force  transfer  Finite-element  model Résumé : This paper presented a modeling study on force transfer around openings (FTAO) in wood-frame shear walls detailed for FTAO. To understand the load transfer in the walls, this study used a finite-element model WALL2D, which is able to model individual wall components, including framing members, sheathing panels, oriented panel-frame nailed connections, framing connections, hold-down connections, and strap connections for reinforcing the corners of openings. The various wall models were validated through laboratory testing of 12 full-scale 2.44×3.66 m (8'×12') shear wall configurations, which included a variety of opening types and sizes. At the wall design load level, the predicted strap forces around openings also agreed well with the test results, in contrast with four simplified analytical methods commonly used in designing shear walls with openings detailed for FTAO. This wall model thus presents a useful tool to check the accuracy of the simplified methods and develop a better understanding of the behavior of wood-frame shear walls with openings. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000592

Modeling hysteretic behavior of wood shear walls with a protocol-independent nail connection algorithm / Minghao Li in Journal of structural engineering, Vol. 138 N° 1 (Janvier 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 1 (Janvier 2012) . - pp. 99-108 Titre : Modeling hysteretic behavior of wood shear walls with a protocol-independent nail connection algorithm Type de document : texte imprimé Auteurs : Minghao Li, Auteur ; Ricardo O. Foschi, Auteur ; Frank Lam, Auteur Année de publication : 2012 Article en page(s) : pp. 99-108 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Wood  structures  Nail  connections  Shear  walls  Hysteresis  Finite-element  method Résumé : This paper presents an extension to an algorithm called HYST to develop the hysteresis characteristics of a nail connection. The paper also discusses the implementation of the algorithm in a finite-element model of a wood shear wall, called WALL2D, to study the hysteretic wall response. The HYST algorithm is a protocol-independent and mechanics-based procedure that considers the nail shank as steel beam elements and the wood embedment medium as compression-only spring elements smeared along the nail shank. By accounting for the stiffness degradation of the wood embedment medium under cyclic loading, HYST can fully address strength/stiffness degradation and the pinching effect in the hysteresis of typical nail connections. HYST was verified by the load-slip hystereses from nail connections tested with two different loading protocols. The WALL2D application model consists of linear elastic beam elements for framing members, orthotropic plate elements for sheathing panels, linear springs for framing connections, and oriented nonlinear springs for panel-frame nail connections. The hysteretic behavior of the nonlinear springs is represented by the HYST algorithm. The wall model was verified by reversed cyclic test results of two types of shear walls. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v138/i1/p99_s1?isAuthorized=no [article] Modeling hysteretic behavior of wood shear walls with a protocol-independent nail connection algorithm [texte imprimé] / Minghao Li, Auteur ; Ricardo O. Foschi, Auteur ; Frank Lam, Auteur . - 2012 . - pp. 99-108. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 1 (Janvier 2012) . - pp. 99-108 Mots-clés : Wood  structures  Nail  connections  Shear  walls  Hysteresis  Finite-element  method Résumé : This paper presents an extension to an algorithm called HYST to develop the hysteresis characteristics of a nail connection. The paper also discusses the implementation of the algorithm in a finite-element model of a wood shear wall, called WALL2D, to study the hysteretic wall response. The HYST algorithm is a protocol-independent and mechanics-based procedure that considers the nail shank as steel beam elements and the wood embedment medium as compression-only spring elements smeared along the nail shank. By accounting for the stiffness degradation of the wood embedment medium under cyclic loading, HYST can fully address strength/stiffness degradation and the pinching effect in the hysteresis of typical nail connections. HYST was verified by the load-slip hystereses from nail connections tested with two different loading protocols. The WALL2D application model consists of linear elastic beam elements for framing members, orthotropic plate elements for sheathing panels, linear springs for framing connections, and oriented nonlinear springs for panel-frame nail connections. The hysteretic behavior of the nonlinear springs is represented by the HYST algorithm. The wall model was verified by reversed cyclic test results of two types of shear walls. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v138/i1/p99_s1?isAuthorized=no

Stability analysis of metal-plate-connected wood truss assemblies / Xiaobin Song in Journal of structural engineering, Vol. 138 N° 9 (Septembre 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 9 (Septembre 2012) . - pp.1110–1119. Titre : Stability analysis of metal-plate-connected wood truss assemblies Type de document : texte imprimé Auteurs : Xiaobin Song, Auteur ; Frank Lam, Auteur Année de publication : 2012 Article en page(s) : pp.1110–1119. Note générale : Génie civil Langues : Anglais (eng) Mots-clés : Wood  structures  Trusses  Bracing  Lateral  stability  Reliability Résumé : This paper presents a study on the critical buckling load and lateral bracing force of metal-plate-connected (MPC) wood truss assemblies. A three-dimensional finite-element method (FEM) based computer program was developed, calibrated, and verified with test results. A preliminary reliability analysis was conducted based on the verified FEM model, with consideration of the variation in material properties and the initial out-of-plane deflection of compression webs. The out-of-plane rotational stiffness of MPC connections has a significant effect on the critical buckling load and lateral bracing force ratio of MPC trusses. The critical buckling load could almost be doubled on the basis of an ideally pinned compression web, and the lateral bracing force ratio was found to be generally less than 1% from the test results and numerical analysis. Consequently, the currently used 2% rule of thumb for lateral bracing design may be conservative, by overestimating the lateral bracing force, and may lead to oversized bracing members. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000502 [article] Stability analysis of metal-plate-connected wood truss assemblies [texte imprimé] / Xiaobin Song, Auteur ; Frank Lam, Auteur . - 2012 . - pp.1110–1119. Génie civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 9 (Septembre 2012) . - pp.1110–1119. Mots-clés : Wood  structures  Trusses  Bracing  Lateral  stability  Reliability Résumé : This paper presents a study on the critical buckling load and lateral bracing force of metal-plate-connected (MPC) wood truss assemblies. A three-dimensional finite-element method (FEM) based computer program was developed, calibrated, and verified with test results. A preliminary reliability analysis was conducted based on the verified FEM model, with consideration of the variation in material properties and the initial out-of-plane deflection of compression webs. The out-of-plane rotational stiffness of MPC connections has a significant effect on the critical buckling load and lateral bracing force ratio of MPC trusses. The critical buckling load could almost be doubled on the basis of an ideally pinned compression web, and the lateral bracing force ratio was found to be generally less than 1% from the test results and numerical analysis. Consequently, the currently used 2% rule of thumb for lateral bracing design may be conservative, by overestimating the lateral bracing force, and may lead to oversized bracing members. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000502

Stability capacity and lateral bracing requirements of wood beam-columns / Xiaobin Song in Journal of structural engineering, Vol. 136 N° 2 (Fevrier 2010) 

Public ISBD [article]  in Journal of structural engineering > Vol. 136 N° 2 (Fevrier 2010) . - pp. 211-218 Titre : Stability capacity and lateral bracing requirements of wood beam-columns Type de document : texte imprimé Auteurs : Xiaobin Song, Auteur ; Frank Lam, Auteur Année de publication : 2011 Article en page(s) : pp. 211-218 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Wood  structures  Beam  columns  Biaxial  loads  Bracing  Lateral  stability Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents a study on the stability capacity and lateral bracing requirements of wood beam-columns subjected to biaxial eccentric compression loads. Material property tests and wood beam-column tests were conducted to provide input parameters and verification to a finite element method based numerical analysis model. The model provided good predictions of the maximum compression load, midspan lateral deflection and lateral bracing force of the wood beam-columns. A parametric study was conducted for the effect of the lateral bracing stiffness, load eccentricity and initial lateral deflections. The adequacy of the 2% rule-of-thumb, Winter’s and Plaut’s methods was also studied by comparing to the test results of the lateral bracing force. The developed model and its output can be used to improve the design methods of the lateral bracing systems of wood beam-columns. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i2/p211_s1?isAuthorized=no [article] Stability capacity and lateral bracing requirements of wood beam-columns [texte imprimé] / Xiaobin Song, Auteur ; Frank Lam, Auteur . - 2011 . - pp. 211-218. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 136 N° 2 (Fevrier 2010) . - pp. 211-218 Mots-clés : Wood  structures  Beam  columns  Biaxial  loads  Bracing  Lateral  stability Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents a study on the stability capacity and lateral bracing requirements of wood beam-columns subjected to biaxial eccentric compression loads. Material property tests and wood beam-column tests were conducted to provide input parameters and verification to a finite element method based numerical analysis model. The model provided good predictions of the maximum compression load, midspan lateral deflection and lateral bracing force of the wood beam-columns. A parametric study was conducted for the effect of the lateral bracing stiffness, load eccentricity and initial lateral deflections. The adequacy of the 2% rule-of-thumb, Winter’s and Plaut’s methods was also studied by comparing to the test results of the lateral bracing force. The developed model and its output can be used to improve the design methods of the lateral bracing systems of wood beam-columns. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i2/p211_s1?isAuthorized=no

Stability capacity of metal plate connected wood truss assemblies / Xiaobin Song in Journal of structural engineering, Vol. 136 N° 6 (Juin 2010) 

Public ISBD [article]  in Journal of structural engineering > Vol. 136 N° 6 (Juin 2010) . - pp. 723-730 Titre : Stability capacity of metal plate connected wood truss assemblies Type de document : texte imprimé Auteurs : Xiaobin Song, Auteur ; Frank Lam, Auteur ; Hao Huang, Auteur Année de publication : 2011 Article en page(s) : pp. 723-730 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Wood  structures  Trusses  Bracing  Lateral  stability  Experimental  data Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the results of an experimental study on the critical buckling load and lateral bracing force of metal plate connected wood truss assemblies. Material property tests—including the modulus of elasticity of dimension lumber, flexural stiffness of plywood panels, and load-slip relationship of nail connection—and full-scale tests of individual trusses and truss assemblies were conducted. The critical buckling load and lateral bracing force were recorded. The continuous lateral bracing, the load sharing and distribution effects, and the residual deformation at the metal plate connections were studied for their influence on the system’s stability performance. The adequacy of the 2% rule of thumb, which is used by some design engineers for lateral bracing system design, was also discussed by comparing to the test results of the lateral bracing forces. The generated database can be used as input parameters and for verification for numerical analysis models and therefore contributes to the improvement of the design methods in the long term. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i6/p723_s1?isAuthorized=no [article] Stability capacity of metal plate connected wood truss assemblies [texte imprimé] / Xiaobin Song, Auteur ; Frank Lam, Auteur ; Hao Huang, Auteur . - 2011 . - pp. 723-730. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 136 N° 6 (Juin 2010) . - pp. 723-730 Mots-clés : Wood  structures  Trusses  Bracing  Lateral  stability  Experimental  data Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the results of an experimental study on the critical buckling load and lateral bracing force of metal plate connected wood truss assemblies. Material property tests—including the modulus of elasticity of dimension lumber, flexural stiffness of plywood panels, and load-slip relationship of nail connection—and full-scale tests of individual trusses and truss assemblies were conducted. The critical buckling load and lateral bracing force were recorded. The continuous lateral bracing, the load sharing and distribution effects, and the residual deformation at the metal plate connections were studied for their influence on the system’s stability performance. The adequacy of the 2% rule of thumb, which is used by some design engineers for lateral bracing system design, was also discussed by comparing to the test results of the lateral bracing forces. The generated database can be used as input parameters and for verification for numerical analysis models and therefore contributes to the improvement of the design methods in the long term. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v136/i6/p723_s1?isAuthorized=no

Strength prediction for rounded dovetail connections considering size effects / Tannert, Thomas in Journal of engineering mechanics, Vol. 136 N° 3 (Mars 2010) 

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